REPORT OX THE GASTEROPODA. 413 



Dr Fischer considers the Challenger shell (of which there is but one specimen) a distinct species 

 from his Oocorys sulcata, but after careful study of his type-specimen I found myself quite unable to 

 separate them. His specimen is larger and has coarser and less sharp sculpture on the last whorl, 

 but these differences I attribute to greater age and less perfect preservation. The Challenger 

 specimen has the spire a little higher, but that is partly a deception of the eye due to the shell being 

 smaller and narrower, and is partly due to the rubbed condition of the apex in Dr Fischer's specimen. 

 The careful measurement of coi'responding parts gives identical results. 



I have quoted Professor Verrill's Bmthodolivm abyssorum with a query because I have not seen 

 his species, and though his description and figure agree on the whole very well with Dr Fischer's 

 species, there still are some difficulties. Thus, Professor Verrill's shell seems to be as much larger 

 than Dr Fischer's as that exceeds the Challenger specimen, and yet at the same time the New 

 England form is said to have but 5 whorls, while Dr Fischer's species has 6^ and the Challenger shell 

 has 5^ ; but where the apex of specimens is eroded, as is the case in Dr Fischer's and the Challenger 

 shells, and most probably too in Professor Verrill's, an element of the greatest uncertainty is at once 

 introduced into the reckoning of the whorls, every one allowing for the absent whorls according to his 

 own fancy. That uncertainty is the greater as regards Oocorys since the form of its embryonic apex 

 is, I believe, unknown. If, then, that apex is exceptionally small, as it is in the closely allied forms 

 of Doliwm and Cassis, a frayed top will seem to present almost the entire tip when not less than two 

 or three whorls are actually absent. 



There is a feature I noticed in the Challenger shell and also in Dr Fischer's specimen which 

 seems worthy of remark because it has not been referred to in either of the descriptions quoted above, 

 but has important bearings on the relation of the genus to Cassis, and especially to Doliwm ; and 

 that is, that there are on the outer edge of the inner lip feeble but unmistakable traces of broad, flat, 

 fold-like teeth which answer to, but are only remotely connected with, the spiral threads and furrows 

 of the exterior. 



The radula of this genus, according to Professor Verrill, somewhat resembles that of Dolium, but 

 his description and figure (see fig. 12b) approach more nearly to that of Cassis. 



Family Apokrhaid.e, Gray, 1847. 

 Genera. 1. Aporrhais, Da Costa. 2. Struthiolaria, Lain. 

 1. Aporrhais, Da Costa, 1776. 

 Aporrhais cancellata (Lamarck). 



Strombus cancellatus, Lamarck, Anim. s. vert., vol. vii. p. 212, and (ed. Desh.) vol. ix. p. 710, sp. 32. 

 Wood, Ind. Test, p. 215, Suppl. pi. iv. fig. 6. 



» j, Deshayes, Encycl. method., vers, vol. iii. p. 995, sp. 21. 



„ fissurella (not of Limie), Sowerby, Genera, vol. ii. pi. ccxxxi. fig. 7. 



»> » Sowerby, Thes. Conch., vol. i. pt. 1, p. 26, pi. viii. figs. 64, 65. 



Rostellaria cancellata, Kiener, Iconog., p. 9, sp. 5, pL iii. fig. 3. 

 Strombus cancellahts, Kiister, Conch. Cab. (ed. Kiister), p. 73, sp. 53, pi. xx. fig. 5. 

 Rostellaria cancellata, Reeve, Conch. Icon., vol. vi. pi. iii. fig. 10. 



October 6, 1874. Amboina. 15 to 25 fathoms. 



