61 



ON BERTHAIS, A PROPOSED NEW GENUS OF MARINE 

 GASTROPODA FROM THE GULF OF OMAN. 



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



Read 8th January, 1904. 



A FEW months ago I published,' m conjunction with Mr. E.. Standen, 

 the description of a small but peculiar Gastropod from the Gulf of 

 Oman, as follows : — 



ScALA (Constantia) intertexta, sp.n. 



" S. testa gracili, fusiformi, albida, delicata, anfractibus 10, quorum 

 apicales tres parvi, vitrei, Iseves, cylindrici, cseteris ad sutums 

 mnltum impressis, pulcherrime regulariter decussatis (aut reticulatis), 

 ad juncturas lirarum spiralium cum costulis fimbriolatis, ultimo 

 anfractu paullum prolongato ; apertura obliqui-ovata, labro eifuso ; 

 columella paullum incrassata, simplici. Long. 7, lat. 1'75 mm. 



"iZ"^^.— Gulf of Oman, lat. 24° 58' N., long 56° 54' E., 156 fathoms." 



The following remarks were added : — " Rarely has a small moUusk 

 caused such perplexity as in the present instance. Two examples 

 alone have occuried, but both have the apex perfect, this being non- 

 heterostrophe, though in most other particulars the form and texture 

 recall such pyramidelloid genera as Monnula^ Pyrgulina, or Mumiola, 

 especially one species of the latter genus, M. spirata, A. Ad., whicli 

 also occurs in the same seas. 



"Mr. Edgar Smith considers Onoha egregia, A. Ad. (which should 

 be removed from that genus), the nearest approach to our shell, and 

 suggests that it might, at all events provisionally, be located in Aclis. 

 In lip -characters it assimilates this genus, while superficially resembling 

 in the decussating sculpture C'/r«o^rfm«!, e.g. dentiscalpimn, Wats. But 

 perhaps the subgenus Const antiaoi Scala is best fitted for its reception, 

 for it seems comparable with C Standeni, Melv., in more than one point." 



This species was extracted from shell-sand dredged at 156 fathoms, 

 in the station as given above, which it is no exaggeration to say has 

 produced a greater number of hitherto unknown mollusca, mostly 

 minute, at one sweep of the dredge, than has occurred since the 

 "Challenger" Expedition and their famous hauls at Stations 23 (Culebra 

 Island) and 122 (Pernambuco), perhaps even surpassing them. 



Shortly after the above remarks were written, it occurred to me to 

 forward the C. intertexta to Dr. W. H, Dall, at Washington, for his 



1 Ann. & Mag. Nat. Hist., ser. vii, vol. xii, pp. 290 sqq. 



