20 



A REVISION OF THE SPECIES OF CYCLOSTREMATIDJE AND 

 LIOTIID^ OCCURRING IN THE PERSIAN GULF AND NORTH 

 ARABIAN SEA. 



By J. Cosmo Meltill, M.A,, F.L.S. 



Read 8th December, 1905, 



PLATE III. 



More than four years have now elapsed since a catalogue of those 

 species of Liotia and Cyclostrema then known to occur in the Persian 

 Gulf and contiguous seas was published,' and already the number has 

 been nearly doubled. No apology, therefore, seems necessary for 

 again approaching the subject and offering a revision to date. This 

 additional material has been entirely received from Mr. Frederick W. 

 Townsend, whose indefatigable powers of research, both as regards 

 Mollusca and other branches of zoology as well, e.g. ichthyology, 

 have already in their results eclipsed the eff"orts of previous in- 

 vestigators in this region. As regards this particular instance, the 

 majority of the species now added, three of which are differentiated 

 as new, came from shell -sand dredged in the Gulf of Oman at 

 a considerable depth, a memorable haul indeed, having already 

 brought to light about one hundred species hitherto unknown to science. 



It has been a matter of some suipiise that no typical species of 

 Teinostoma, A. Ad., has yet occurred. It will be noted the name 

 Vitrinella, C. B. Ad., will be in this paper employed subgenerically, 

 and after much deliberation I believe this the correct course to take. 

 Instituted in the year 1 850 by Professor C. B. Adams for a series of 

 small, widelj' umhilicated, often hyaline, mostly smooth, spiral shells 

 from California and other West American shores, Vitrinella was much 

 added to by Dr. Philip Carpenter in his Mazatlan Catalogue, and 

 subsequently by Mr. Andrew Garrett in dealing with species from the 

 Pacific Isles. '^ At the best, however, it ranks as an obscure genus, 

 and consists, we believe, in greater part, of an ' olla podi'ida,' from 

 which several Cyclostremata and Adeorbes might be extracted. But 

 few are figured, and many have as their types unique dead dredged 

 examples, confessedly imperfect, not easy of access, and therefore, 

 from a scientific point of view, comparatively worthless. 



It may not be generally known that the celebrated author of 

 " Peter tSimple," " Midshipman Easy," etc., Captain F. Marryat, C.B., 

 F.R.S., was the founder of the genus Cyclostrema in the year 

 1818, his type being the rare C. cancellatu7n,^ Marryat, from the 

 Philippines. 



1 Proc. ZooL Soc, voL ii (1901), pp. 345-347. 



2 Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 213, pL xxi, figs. 13-17. 



3 Captain Marryat considered the genus feminine, his type heing given as C. cancellata, 



but if derived from kvkXos and TpTJ/ia, as is probable, it must be of the neuter 



