ON THE FILAMENTOUS, LONG-HORNED DIATOMACEiE. 105

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1 ON THE FILAMENTOUS, LONG-HORNED DIATOMACEiE. 105 On the FILAMENTOUS, LONG-HORNED DIATOMACE/E, toith a Description of two new species. By THOMAS BRIGHTWELL, F.L.S. IN a gathering of Diatomacese, made by the late Mr. Wigham in July 1854, on the borders oi the salt-water estuary, called Breydon, near Yarmouth, a singular filamentous, horned species was detected, allied to the genus C/xctoceros of Ehrenberg. An examination of this singular organism, (the first of the family which has occurred in this country), and a comparison of it with the allied forms described by Ehrenberg and Dr. Bailey, afford materials calculated to ^extend and correct our knowledge of this rather doubtful group of Diatomacea?. Mr. Wigham's discovery will also, we trust, induce surviving labourers in the same field, to endeavour to add to our knowledge of existing species, as much must yet be brought to light before a satisfactory classification of this group can be effected. Most of the described species have been found only in a fossil, or rather, if we may so term it, a deposit state ; and in this state it is clearly difficult to form a correct idea of either species or genera, since deposits give no information as to the Diatoms being in threads or solitary frustules. From this circumstance, and a disposition to describe every variety of form, and even many fragments of Diatoms, as species, both species and genera have been multiplied to a perplexing extent. It appears probable that there are few, if any, instances of truly fossil Diatoms, but that all the so-called fossil species are only deposits from still-existing and living species ; and it is only when we have the living Diatom before us, that we can give any specific or generic characters that can be at all relied upon.* The discovery of a new and living species of Chaitoceros, and a careful examination of most of the species of this and several other allied genera, described by Ehrenberg as found in a fossil state, have satisfied us that most, if not all these, will, when found in a living state, turn out to belong to the singular filamentous and horned group, which may for the present, with some extension of its character (such as is hereafter attempted in this paper), be comprehended in the genus Cluetoceros. The typical species of Ehrenberg's genus appears to be C. * Tu proof of this, Khrcnberg's genus Biblantm seems entirely composed of the disjecta membra of several genera, as Tetracyolus, Odontidium, and some others. Tetracyclus emarginatus, Wm. Smith, {Biblarum emarginatum, Ehr.,) bas been found recently, in a living state, both in Ireland and Scotland.

2 106 BRIGHTWELL, ON THE FILAMENTOUS, didymus. This occurs not unfrequently in guano. The horns proceed immediately from apertures on each side of the frustules (an essential character of Ehrenberg's genus), and differ in this respect from our newly-discovered species, in which the horns proceed from, or rather are an elongation of the intermediate rings. Two species from the Antarctic Sea are briefly described by Ehrenberg (C. dichceta and C. tetracliceta); each frustule is smooth, and the horns (of which the former species has two on each side, and the latter four) are very long and filiform. These species were, we believe, found in pancake-ice, and were brought home by Dr. J. D. Hooker. Two species from Bermuda earth, marked as doubtful, are described by Dr. Bailey (C. bacillaria and C. diploneiis), and he has also recently described and figured a remarkable species, named by him C. boreale, found in the stomach of Botriodactyla grandis.* The horns of this species are very long, and armed with numerous minute spines. Dr. Bailey describes and figures a small species also found in guano, named by him C. incurvum, which we have found plentiful in South American guano. Of the allied genus Goniothecium, eight species are described by Ehrenberg, all found in the Richmond earth, North America. The two largest and most common are G. Rogersii and G. odontella, and we think it probable these will turn out, if discovered in a recent or living state, to be Chcetoceri. Of the remaining six species, we are led to conclude, from the discovery of the Breydon species, that two of them belong to the genus Chmtoceros, and are, when living, filamentous. They are Goniothecium gastridium, of which we have found many specimens with the horns perfect, and G. crenatum. A figure of a frustule of this species is given in the Microgeologie of Ehrenberg; and it can scarcely be distinguished from the frustules of the Breydon species. Similar frustules are of frequent occurrence in African and other guano, and in several fossil earths of marine formation, and we have detected recent specimens in a gathering lately sent us from Monterey Bay, North America. Goniothecium hispidum and G. didymum of Ehrenberg, scarcely appear to differ from some of the smaller frustules of the Breydon species. G. navicula and G. barbatum are marked by Ehrenberg as doubtful species of Goniothecium ; but are clearly allied to G. crenatum, or our Breydon species. Several other fossil genera of Ehrenberg contain species which will probably be found to belong to the long-horned filamentous Diatoms. Xanlhiopyxis civgulata has precisely * See Smithsonian Contributions to Knowledge, Feb. 1854, pp. 8, 9.

3 LONG-HORNED DIATOMACKffi. 107 the cup-shaped and hispid character of our Breydon species, but is destitute of the neck. Syndendriwn diadema and Dicladia capreolus are common species ; they are found with the other Chcetoceri, in various earths, and guano, and appear to be of the same family. They are chiefly distinguished by long styles, proceeding from the rounded end of the frustule, which styles are branched at the end, and are not unfrequently found with a portion of the membrane adhering to them, in which they seem to have been imbedded. Omphalotheca hispida has the appearance of an imperfect frustule, and Mastogonia prmtexta, of a semi-frustule of Goniothecium Roger sii. We venture to give a synopsis of the Chcetoceri, adapted to our present imperfect state of knowledge of these singular organisms. CH2ET0CBK0S. Filamentous ; filaments elliptical, fragile, imperfectly siliceous. Frustules without stria}, united in pairs by the' interlacing on each side, of horns proceeding from the frustules, or from a cingulum between the frustules. Horns often of groat length, and sometimes spinous, or serrated. $ Horns, four on each side. 1. C. Tetracheta, Ehrenb., Kutz., spec. Alg Horns, two on each side, and proceeding from tubular apertures in the frustules. * Horns filiform Dichceta, Ehrenb., Kiitz., spec. Alg Didymus, Ehrenb., Kutz., spec. Alg C.? Bacillaria, Bailey, Kutz., spec. Alg ? Biploneiis, Bailey, Kutz., spec. Alg C. Gastridium, Goniothecium, Gastridium, Ehrenb., Kutz., spec. Alg. 23. See Plate VII., figs N. B. To Ehrenberg's description should be added, " Cornubus utrinque duobus." This species clearly belongs to the genus Ohcetoceros. Many examples have occurred with the homs perfect. See Plate vii., fig. 7. C. incurvum, Bailey. Smithsonian Contributions, Feb. 1854, p. 9. Plate VII.,figs We have found this species abundant in guano. Mr. Tuffen West has detected in guano frustules of a species, belonging to this section, which is new to me, and may perhaps be C. Bacillaria, Bailey. For figures of these frustules see Plate VII., figs. 1, 2. ** Horns spinous, or serrated horeale, Bailey. Smithsonian Contributions, Feb. 1854, p. 8. Plate VII., figs Peruvianum, Brightwell. Frustules hemispherical. Horns proceeding from the centre of the circular end; very stout and long, and beset with short spines, recurved. * I am also able to state, that G. Wighamii and Goniothecium hispidum have lately been gathered in the bay of the Isle of Eoa, near Ulverstone.

4 108 ON THE FILAMENTOUS, LONG-HOKNED DIATOMACEJE. In guano from Cailao, occurring in small flakes or patches full of pieces of the horns, and a few detached frustulcs. Plate VII., figs Horns proceeding from, a ciiigulum or ring, dividing the frustules. \0. 0. Wighamii, Brightwell. Frustules cup-shaped, with a band round the, mouth of the cup, and a neck or bulb, proceeding from the centre Frustules beset with minute short spines, or papillte, in all parts, except the band. Oval, on a front, or end view, the spin«s appearing as minute specks. Boiled in acid, the filaments break up, and the frustules, in an isolated state, and detached rings, with the horns proceeding from them, are all that can be detected. The rings may readily be distinguished from the frustules seen endwise, as they are open, and without dots; while the frustules, seen endwise, are dotted. In brackish water, near Breydon, Great Yarmouth. Plate VII., figs We have named this species after the discoverer, Mr. Wigharn, an excellent practical botanist, indefatigable in the pursuit of his favourite study, and most liberal in his communications to his friends cremation, i All these species are described or figured by Ehren- 12. C. hispidum. I berg, from frustules found in a fossil, or deposit navicula. j state, and appear to belong to this section of the 14. C. barbatum. J genus Chcetoceros.* The G. Wighamii was, as before stated, found near the salt-water estuary, called Breydon, at the point where the rivers Yare and Wavency meet. It occurred in a gathering made from a dirty ditch of brackish water, at the back of a small public-house, called " The Burney Arms," which is marked on the Ordnance maps. The gathering abounded in Oampylodiscus clypeus (a species chiefly known before as occurring in fossil earth from Bohemia), and in one or more species of Mastogloia; it also contained Bacillaria paradoxa, Amphora salina, Navicula pedpebralis and tumens, Mdosira varians and subflexilis, and the Viva bullosa (*); and Frotococcus hcematodes (?) abounded also in it, with which last the Chcetoceros seemed most associated. It was perhaps parasitical on some Algjc, and, after being detached, had floated to where it was discovered. This place has been frequently visited since Mr. Wigham's decease, and searched in vain, for the Ohcetoceros ; although most of the above species We subjoin a reference to the figures of most of the species above referred to, given in the Plates to Ehrenberg's Miorogcologie. Mastogonia Goniotheciutn. j> >>» Chaitoceros. Xanthiopyxis. Chajtocerns Kyndendrium. Dicladia.. Omphalothuca.. pratexta, Plate XIX.. Kogersii. Plate XVIII.. odontella. '.. gastridinm..... didymum..... navicula..... hispidum.... barbatum..... crenatum, Plate XXXIX.. didymus, XXXV.. cingulata, XXXIII.. diploneiis. diadema, Plate XXXV.. caprcolus,..... hispida A. XVIII. XVII.. XV11I. A. XVlli A. xvni. A. )X. 4, and XVII

5 HEPWORTH, ON THE MICROSCOPE. 109 were met with. In the living species of C. Wighamii, the endochromc was seen of a green colour, and aggregated in the centre of each frustule, in the manner represented in the figures of Encamjria zodakus, in Kutz. Bac, PI. XXT., fig. 21, and Pritchard's Infusoria, PI. XIII., fig. 43. No appearance of conjugation has been observed, nor have we been able to detect in this, or any other of the species, mentioned in this paper, which have come under our observation, any striaj, or markings of that kind. We have detected most of the species above described in guano (chiefly from Callao), and especially in little transparent flakes or patches containing a mass of frustules. C. f/astridiurn, ineurvum, Wighamii, and Peruvianum are of most frequent occurrence. There can be little doubt that all the guano of the coast of Peru is in like manner pervaded with these organisms, and if so, we ought to look to this locality for living species. C. Wighamii has, as we have already stated, been lately gathered in Monterey Bay, and a careful search would probably bring other species to light. The discovery of a number of specimens of C. boreale in the stomach of a large species of Holothuria, or Sea-Cucumber, should lead to the examination of the stomachs of Sea-Slugs, especially of such as are known to feed on marine AlgEe, for specimens of this singular and interesting group of DiatoinaceiE. OBSERVATIONS on the PRACTICAL APPLICATION of the MICRO- SCOPE. By J. HKP WORTH, Esq. THERE are yet some parties in the medical profession who are sceptical as to the utility of the microscope. I have found it occasionally of practical importance; and perhaps if I mention a few cases, it may not be uninteresting to the medical readers of the ' Journal.' J. M., a young man, aged twenty-three, applied to me, bringing, in a bottle containing some fluid, a lock of hair, and stating that he had vomited it in the night; that he believed it had been in his stomach three months, during most -of which he had been under medical treatment for almost constant vomiting, and he thought this had been the cause. I examined the hair, and from the fact of the bulb and sheath being complete, I concluded it had not been in the stomach at all, or the gastric fluid would have dissolved these portions of it. I suggested that it might have been thrown into the vessel into which he vomited : that was found to be the case, on inquiry, although he left with an impression that