MELVILL : GASTROPODA FROM THE PERSIAN GULF, Ei'C. IGl 



The most frequent of the three species found together in the above 

 locality. It seems almost intermediate between S. alta and aedonm, 

 both of Watson,' from the Azores and Pernarabuco respectively; but 

 is quite distinct from either. The rarer species associated with it 

 are S. cetherta, M. & S., and what seems to be S. coronata, Watson,- 

 the type of which came from Tahiti. I have especial pleasure in 

 naming this beautiful little moUusk after Mr. John Wilfrid Jackson, 

 who has given much needed assistance in sorting the di'edged material, 

 and was the first to extract this species therefrom. 



Cerithium anembat0m,^ n.sp. PL X, Fig. 6. 



C. testa parva, fusiformi, solidula, pallide albo-fusca, anfractibus 12, 

 quorum apicales 4, vitrei, nitidi, Isete ochracei, sub lente spiraliter 

 unicarinati, caeteris apud suturas impressis, quatuor supernis spiraliter 

 tri-, tribus his proximis quadri-liratis, liris papillosis, ultimo anfractu 

 8-10 lirato, apertura ovato-rotunda, labro tenui, canali brevi. Long. 5, 

 lat. 150 mm. 



A very small species, but I think quite adult. The apical whorls 

 are shining, ochraceous, once spirally keeled, the remainder being 

 papillosely transversely Urate. It is not very frequent in siftings 

 from the above dredging. 



Cerithium pervicax, n.sp. PI. X, Fig. 7. 



C. testa minuta, albida, interdum pallide fusca, delicata, anfractibus 

 9-10, quorum 3-4 apicales, ochraceo-fusci, nitidi, laeves, sub lente 

 forte ad medium unicarinati, caeteris ad suturas multum impressis, 

 gradatulis, nequaquam varicosis, supernis spiraliter bi-, ultimistriseriatis, 

 gemmulatis, ultimo infra peripheriam unicarinato, apertura subrotunda, 

 labro tenui, marginem apud columellarem nitido, crassiusculo, canali 

 brevissimo. Long. 3, lat. 1 mm. 



My coadjutor (Mr. R. Standen) and I, in describing Cerithium 

 verecundum,^ mentioned this as but a form of that shell. A closer 

 research has satisfied me as to its specific difference. Much smaller 

 than C. verecundum, long. 3 as against 4*20 mm., it is broader in 

 proportion, and no trace of varices is to be seen. The mouth 

 is rounder, not prolonged towards the base, the canal remarkably 

 short. It is as abundant in shell-sand from the above locality as its 

 neai'ly allied species is scarce. Of the true C. verecundum I have not 

 noticed more than twelve examples, as against two hundred or more 

 of C. pervicax. 



BiTTiuM caudatum, n.sp. PI. X, Fig. 8. 



B. testa minutissima, cylindrica, solidula, pallide brunnea, apud 

 apicem multum attenuata, anfractibus 10, quorum apicales 4 nunc 



' Rep. " Challenger" Exped., vol. xv, pp. 114, 115, pi. viii, figs. 1, 3. 



' L.c, p. 114, pi. viii, fig. 4. 



^ on/e'/U/Saros, inaccessible. 



^ Ann. & Mag. Nat. Hist., ser. vii, vol. xii, p. 300. 



VOL. VI. — SEl'TEMBEK, 1904. 12 



