257 



NOTES ON NASSOBONTA INSIGNIS. 

 By Edgah a. Smith, F.Z.S., etc. 



Head March 8th, 1895. 



The species under consideration was described by H. Adams in the 

 Proc. Zool. See. 1866, p. 445, and figured on pi. xxxviii, fig. 8. 

 He created for its reception the new genus Nassodonta, which he 

 placed in the family Buccinidae, but without offering a comparison 

 with any particular section of it. After carefully studying his 

 diagnosis, I fail to discover any cliaracters which may not be found 

 in the genus Nassa taken in a broad sense ; indeed, many forms in that 

 group are far more widely separated from one another, than Nassodonta 

 is from several of them. He described the outer lip in these words : 

 " labrum acutum, intus incrassatum et dentatum, extus antice denti- 

 culo instructum." In the diagnosis of the species no further mention 

 is made of the latter character, but the teeth within the labrum are 

 said to be two in number. On examining Mr. Adams's type specimen 

 in the Museum, it will at once be seen that the above diagnosis is very 

 inaccurate. In the first place, there are four distinct denticles, and 

 that which is said to be " extus," does not in fact exist. Certainly on 

 the acute margin of the lip, at the termination of a groove, which 

 passes round the base of the body-whorl, there is a feeble dentiform 

 prominence, which, however, cannot be described as a denticle on the 

 outside {extus). Similar but more distinct marginal denticles are met 

 with in Nassa glans and some other species. The animal and oper- 

 culum are unknown. The allegation of its occurrence in fresh water 

 (a statement which I shall presently show to be very doubtful) did 

 not warrant Mr. Adams in separating it from JYassa, for fluviatile and 

 marine species do, in a few cases (e.g. Neritina), occur in the same 

 genus. Fischer (Man. Conch., p. 635) doubtfully considered it a 

 section of Canidia. Tryon, however (Man. Conch., vol. iv, p. 37), has 

 placed it in Zeuxis, a subgenus of Nassa, a location with which 

 I fully agree. ^ 



With regard to the locality assigned to this species, I think there is 

 also some mistake. It is given by Adams "River Peiho, China, in 

 company with Velorita.''^ As far as I can ascertain, the genus Velorita 

 occurs only on the west side of the Indian Peninsula, in the neigh- 

 bourhood of Cochin, and in the estuary of the River Kundapur, where 

 it is largely eaten by the natives. It has never been found in China, 

 and the original locality "Japan," quoted by Gray, evidently is also 

 an error. I should here mention that on a label accompanying Mr. 

 Adams's specimen of Nassodonta, the locality is thus written : " Peihoi, 



^ Martens also suggested Nassa. Zool. Eec. 1866, p. 179. 



