^04 



A REVISION OF THE SPECIES OF TEREBRA 

 OCCURRING IN THE PERSIAN GULF, GULF OF OMAN, 



AND ARABIAN SEA, AS EVIDENCED IN THE 

 COLLECTION FORMED BY MR. F. W. TOWNSEND, 1893-1914. 



By JAMES COSMO MRLVILL, M.A., D.Sc, and ROBERT STANDEN. 

 (Read before the Society, March 8th, 1916). 



It is nearly fifteen years since we published our first account of the 

 Marine Gastropoda of the Persian Gulf, and naturally many species 

 new to the district, or to science, have been more recently collected, 

 many also found in new localities, and at different depths, and some 

 curious variations have likewise occurred. Certain emendations and 

 corrections have also, naturally, to be made, and accordingly a revision 

 of certain of the genera becomes necessary. 



The genus Terebra is one of the most admired and graceful of all 

 the marine gastropoda ; and though most of the Persian Gulf region 

 treated of in our paper is outside the Tropic of Cancer, some of the 

 larger and finer species are found, though perhaps not very commonly, 

 while several smaller endemic species, mostly made known by the 

 dredgings of Colonel, afterwards Sir Lewis, Pelly, K.C.B., and de- 

 scribed but not figured by Mr. Edgar Smith in the Ann. and Mag. 

 N.H., 1877, occur in local plenty. 



This genus has been split up into various sections and subdivisions, 

 which are referred to in another paper brought out by one of us simul- 

 taneously with this, but it seems to us that, with the exception of the 

 sub-genus Mazatlania Dall {Euryla H. and Ad., noft Gistel) that they 

 are not very necessary, so great a family likeness prevails throughout 

 the whole series of over two hundred recent species. Of these, 

 about one-seventh, say thirty-five, occur in the region we are now 

 considering ; which we proceed to give in alphabetical order, 

 with references to where a description or figure may be found ; and 

 giving additional localities where they have been dredged by one 

 of the most careful observers and collectors of the day, Mr. Frederick 

 W. Townsend. We are sorry to say he has now retired, so that the 

 series brought home by him in 19 14 will be the last trophies, 

 we fear, for very many years to come from the Persian Gulf, Gulf of 

 Oman, and Arabian Sea. 



I. — Terebra ambrosia Melv. 

 T. avibrosia Melv., Proc. Malac. Soc, x., p. 250, pi. xi., fig. 10, 1912. 

 Hab. : M.C., Charbar, 5 fathoms, sand. 



Slightly larger than the allied 71 cognata Smith, the type measuring 

 long., 16; lat., 4*50 mm. The purplish-plum colour is very char- 



