OF SOUTHERN INDIA. 141 
cancelled.* Gray (Guide, 1857, p. 17) does not separate Cyclops from Nassa at all, 
while other writers think the Cy. neriteus is only an abnormal form of some other 
species of Massa. Chenu obtained a new species of Cyclops from the Crimean sea, 
Oy. kamiesch (vide Manuel, p. 165), which in general form agrees with the other 
Mediterranean species, but neither the animal nor the operculum has been made 
known of this second species. Comparing the animal of Cyclops neriteus with that 
of Nassa, it must be agreed that they are, strictly speaking, perfectly identical, 
and that the opercula of both are very similar, or at least not more different 
than in other forms of the so-called sub-genera of Massa. The only difference 
exists in the form of the shell, and in comparing this, for instance, with species 
of the sub-genus duricularia (Adams’ Gen. I, p. 118), we meet forms evidently 
indicating a passage to Cyclops, differing from it almost solely by the short 
transverse ribbings. It appears quite sufficient to retain Cyclops as generically 
distinct from Massa, but at the same time certainly to retain both in one sub-family. 
Fossil species, ike Massa gibbosula and a few others of upper tertiary age, belong to 
Cyclops. Teinostoma, Adams (Gen. II, p. 615), is justly referred to the Rorzzzrpx of 
Gray (uusonmv#, Adams), and I believe the jurassic fossil species like Zrochus 
Moreanus, D’Orb., or the species of Helicocryptus are most nearly related to it. The 
family Rorzzzrp# has many more fossil than recent representatives, and some of the 
oldest known Gastropoda belong to it, but they are as yet dispersed under all the 
genera of Trocurp“; only comparatively few have been described as Rotelle, 
some even as Delphinule. 
Regarding the numerous sub-genera of Nassa quoted by Adams, it is difficult 
to form an idea as to their relative value, and so long as they are not supported by 
the examination of the respective animals, they must be looked upon merely as 
convenient sections or divisions of Nassa. It must, however, be granted that 
forms like Zaphon (=? Aciculina, H. and A. Adams, 1853, non id. Deshayes, 1864), 
Uzita, Naythia, and others ought to be generically separated, although it will be 
difficult to follow these and other divisions in fossil Conchology, but probably only 
because the number of the fossil species as yet known is comparatively very 
small. The jurassic genus Purpurina, D’Orb., is generally referred by French 
authors to the family Buccryrpz, but there is not much support to be found for 
this classification in the formation of the shell. We shall mention the genus 
again in the family Trrcxorrorrp.z. 
ce. Subfamily —COMINELLIN# (Gray, Guide, 1857, p. 15). 
Genera; 1. Commella, Gray, 1847. 
2. Truncaria, Adams and Reeve, 1848. 
3. Hburna, Lamarck, 1801. 
* Chenu, as seen from several other instances, does not appear to have noticed Adams’ Appendix, 
pp. 614-648, at the end of the IInd Volume. There are several very important and valuable additions and 
corrections to be found in it. 
2N 
