226 



HARDWICKE'S SCIENCE-GOSSIP. 



adjective generic names (such as Hyalina) cannot be 

 used." 



Now as to Z. alginis not differing from Hyalina, 

 Continental authorities are fairly well agreed that it 

 does sufficiently to warrant a separate generic name, 

 and I cannot help thinking likewise. 



With regard to the other argument, it is absurd to 

 suppose that ( the "rules of the British Association " 

 are going to bind down foreign authors, and besides, 

 what about Succinca? Nevertheless, Dr. Jeffreys' 

 opinion is one that should not be lightly ignored, and 

 so it will be interesting to see if any evidence can be 

 brought forward against my view of the case. 



I am greatly indebted to Mr. Ponsonby, of Halkin 

 Street, for the opportunity of seeing his valuable 

 series of British Hyalina:, many of which have been 

 sent to Dr. Boettger in Germany, and which have 

 been returned with the names affixed to them, 

 according to his view of the question. 



Hyalina cellaria. — Common throughout the district. 

 My largest specimen is from Kenley in Surrey, it is 

 about three-eighths of an inch in diameter. This 

 species resembles Hy. Draparnaldi closely, but I 

 think they are distinct. The latter has not.yet been 

 found in our district. Var. compada, Jeff, has been 

 recorded. Var. albinos, Minster and Kenley. 



Var. shell greenish-white and transparent. One at 

 Maidenhead, a few on a mossy bank (the moss was, I 

 believe, Polytrichum commune, L.) by the side of the 

 high-road, between Wrotham and Eynsford. "When 

 I first found the single specimen, which was immature, 

 at Maidenhead, I identified it as alliaria var. viriditla, 

 Jeff, as it had a strong garlic odour ; but I find that 

 the young of both cellaria and of glabra, Jeff, have a 

 garlic odour, and as the shell is in shape exactly like 

 a young cellaria, and like the more mature Kentish 

 examples of the greenish var., I am obliged to refer 

 it to cellaria. 



I have referred the Maidenhead specimen to Dr. 

 Gwyn Jeffreys, and he returned it with the note 

 " The variety of Zonites cellarius is my albida." This 

 being the case, it would seem that the milk-white and 

 opaque var., which would also, I suppose, be var. 

 albida (I have referred to it above as albinos, Moq.), 

 is not to be separated from the greenish and trans- 

 parent form. 



Hyalina glabra, Stud. (Jeff).— Mr. Ponsonby 

 submitted some of these to Dr. Boettger, who 

 returned them as what the German conchologists 

 called alliaria, and some of our British alliaria he 

 called young cellaria, others young alliaria = glabra, 

 Jeff, and another British specimen he identified as 

 Hy. pdronclla, Charp. Moreover, he sent some of 

 what he called glabra, Stud., to Mr. Ponsonby, and 

 these were, without doubt, perfectly distinct from the 

 glaber of British conchologists. From this it seems 

 that there is a great gulf between the British 

 and German notions of the species of Hyalina; 

 which we are to adopt seems uncertain, but it seems 



extremely desirable^that the matter should be cleared 

 up. Jeffreys considered H. petronella to be the same 

 as Hy. excavata v. vilrina, but Dr. Boettger's 

 specimen is very different from this. In the British 

 Museum some examples of Hy. glabra, Jeff, stand as 

 a Ilia ri us. 



I have taken glabra, Jeff, in Kent and Surrey, in 

 which counties it would seem to be abundant, but I 

 fancy it does not occur in the Isle of Thanet. One 

 specimen at Hanwell (S. C. Cockerell). I found a 

 greenish -white and transparent variety (viridans of 

 my note book) at Bromley, Kent. 



Hy. nitidula. Common throughout the district. 

 Var. Helmii, this is the white form ; alba would have 

 been a much better name for it than Helmii. 

 Near Chislehurst, but rare. I found a curious variety 

 at West Northdown, Thanet, having four whorls, the 

 last whorl expanded, and shell larger than usual, and 

 of a dull waxy appearance, slightly whitish beneath, 

 and having a rather broad brown band below the 

 periphery ; band formula 00005. 



Hy.pitra. — The so-called " type " seems to be less 

 common than the var. margaritacea, which is white. 

 As far as I can remember, I have, taken the type only 

 near Godstone, Surrey, but I have found the variety 

 at Farnborough, Addington, near Dorking, near 

 Shiere, Haslemere ; andJMr. Ponsonby has a specimen, 

 from Leatherhead. 



{To be conlimied.) 



CHAPTERS ON FOSSIL ;SHARKS AND 

 RAYS. 



By Arthur Smith Woodward. 



IV. 



Petalontid,e, continued. 



[From f>agc 156.] 



CLOSELY related to Petalodus, and from the same 

 geological horizon, is Ctenopetalus, which differs 

 in the shape of the root and the coarseness of the 

 serrations ; and not far removed, also, is the curious 

 Polyrhizodus. This tooth (fig. 155) differs chiefly in- 

 being stouter and larger, in the absence of serrations 

 on the cutting edge, and in having the root divided 

 into a number of "radicles." Nothing is known of 

 the arrangement in the mouth of either of these 

 forms, and we are thus left to supply the deficiency 

 by inference. 



Proceeding to Petalorhynclucs, which is also a 

 Lower Carboniferous genus, we find the fossil remains 

 a little more complete and instructive. Numerous 

 specimens have been obtained from the Mountain 

 Limestone of Armagh by the Earl of Enniskillen, 

 and Mr. J. W. Davis published the results of his 

 study of them in the Trans. Roy. Dublin Soc. for. 



