1G On Marine Mollusca from the Persian Gulf, &c. 



quorum apicalis ipse bulbosus, pervitreus, duo liiuc proximi 

 vitrei, arete longitudinaliter costulati, tertius unicariuatus, carina 

 crenulata, caeteris apud suturas impressis, spiraliter tornatis, 

 bicarinatis, carinis regulariter brunneo-maculatis et lineatis, 

 interstitiis arete spiraliter liratis, albis, ultimo anfractu multi- 

 lirato, ad peripberiam fortiter bicariuato, carinis, praesertirn 

 superiore, regulariter brunneo-maculatis, Kris omnibus simili 

 modo ad basin brunneo-lineatis ; apertura ovata, labro tenui, 

 sinu conspicuo, columella recta, canali prolongato. 

 Long. 32, lat. 6 mm. 



Hah. Persian Gulf. 



Of this fine addition to the Pleurotomidse I have only 

 seen the type specimen, but am informed that others have 

 been found. This is in very perfect condition, and belongs 

 to the typical section of the genus, which has been compelled 

 to have its well-known generic name Pleurotoma, Lam., 1799, 

 altered, owing to one year's priority of Turris only. It 

 perhaps most resembles the larger and more elongate T. mar- 

 rnorata, Lam., but the abbreviate form distinguishes it at a 

 glance from both this and other allies. I am especially 

 indebted to Mr. G. B. Sowerby for first calling my attention 

 to this species. 



Betusa turrigera, sp. n. (PI. II. fig. 28.) 



H. testa abbreviato-cylindrica, tenui, alba vel pallide straminea, 

 spira gradata ; anfractibus 4, quorum apicalis parvus mamillatus, 

 subvitreus, caeteris turrigeris, laevibus, parum nitidis, ultimo 

 interdum ad medium constrictulo, interdum normali ; apertura 

 ovata, subtus latiore, labro fere recto. 



Long. 2*75, lat. 1*25 mm. 



Hab. Persian Gulf, Mussandam. 



A compact species, the whorls angularly turreted above, 

 quite smooth, dull white or straw-coloured, the mouth widened 

 basally, ovate ; outer lip sometimes, with basal whorl, con- 

 stricted in the centre, at other times quite normal and straight. 

 We do not know a near ally, at all events in this fauna. 



Lepton orientate, sp. n. (PL II. fig. 29.) 



L. testa subaequilaterali, percompressa, explanata, tenui, alba, sub- 

 pellucente, superflcie delicate sed irregulariter concentrice striata, 

 striis sericatulis, umbonibus prominulis, approximatis, margine 

 dorsali antice paullum excavato, ventrali prope recto, pagina 

 interna albo-lactea, cardine normali. 



Alt. 3, diam. 4 mm. 



