OF SOUTHERN INDIA. 441 
species having been under these names figured by the same author already in 
his “Traité elem. de Conch.,” pl. 61, figs. 18, 15, 16, and figs. 11, 12,14. Thus 
all the species of Siphonodentalium known at present are six, one recent and five 
tertiary. 
6. Gadila, Gray, 1847 (Proc. Zool. Soc., London, 1847, p. 159—Gadus, 
Montagu, teste Rang, non id. Linn). Shell tube-like, generally of moderate length, 
thin, almost hyaline, smooth, thickest near the middle, somewhat contracted 
towards both ends, more so towards the posterior one; margin of both ends entire. 
The animal is similar to that of Siphonodentalium, under which generic name 
Sars described a recent species, Gadila (Siph.) subfusiformis (Forhandlinger i 
Vidensk., 1864, p. 301, figs. 36-44). 
The oldest known species evidently belonging to this genus is the (tertiary or 
recent?) Dentaliwm gadus, Montagu (or Lamarck teste Deshayes),* for which, 
according to the authority of Rang, Montagu ought to have used the generic name 
Gadus, though this poimt is by no means very clear. In his Manuel of 1829, 
p. 116, Rang simply states that he unites Vaginella of Daudin and Gadus of 
Montagu with his sub-genus Cresis (non Créséis). 
The name Gadus having been, however, previously used by Linné, it cannot be 
here applied again, as proposed by Deshayes in his last edition of Paris fossils and 
followed by Conrad and others (Am. Journ. Conch. II, p. 75). From the descrip- 
tion given by Rang of Cresis, it is also evident that his species belongs to the 
Preropopa, and therefore Gray’s name Gadila must be retained for this group 
of shells. Lamarck’s Dent. coarctatum, figured by Chenu in his “ Illust. Conchil.,” 
is stated to be identical with Gadila Gadus, Mont. Several other fossil species, 
however, also belong to this genus, which appears to be represented already in the 
lower jurassic strata; it is even possible that some of the paleeozoic Hyolithes belong 
to Gadila or allied genera. The cretaceous species will be mentioned subsequently. 
6a. Helonyx, Stimpson, 1865, (Amer. Journ. Conch. I, p. 63). This name 
was proposed for Dent. clavatum, Gould, the animal of which Stimpson observed 
in the Hongkong harbour, where it lives on the muddy bottom at a depth of about 
20 fathoms. The shell does not appear to differ from Gadila, but the animal is 
figured with a rather pointed foot, while the description says that it is “ obtuse at 
the extremity.” It does not appear, however, to terminate with such a flat disk 
as observed in the species described by Sars, and until further researches have been 
instituted, it may seem desirable to retain Stimpson’s name, at least for the one 
recent species. 
7. Pulsellum, Stoliczka, 1868. (Siphonodentalium, Sars, ex parte). Shell 
tubular, thin, smooth, or longitudinally ribbed, gradually tapering towards the 
posterior end which is truncate, with the margin entire. This genus is proposed 
to include the three recent species described by Sars as Siphonodentalium lofotense, 
affine and pentagonum (Forhandliger Vidensk., etc., 1864, p. 297, etc.). The animals 
closely resemble those of Siphonodentalium vitreum, only showing slight differences 
* Traité de Conch., p. 36, pl. 61, figs. 8-10. 
5Q 
