MELVILL : ON GASTROPODA FEOM THE PERSIAN GULF, ETC. 57 



decorata, spinigera, spinis paucis regularibus, latis, brevibus, numero 

 ultimum apud anfractum circa 12-13, ultimo apud basin producto, 

 apertura anguste oblonga, labro paullum expanse, ad medium angulato, 

 tenui, sinu indistincto, canali longa, paullum recurvirostri. Long. 9-5, 

 lat. 4 mm. (sp. maj.). 



^^^.—Persiaa Gulf, Gulf of Oman, lat. 24° 58' N., long. 56° 54' E., 

 156 fathoms. 



The author of the genus, having kindly examined my specimens, 

 pronounces them generically the same as the Western A. elegans and 

 A. r ad lata, Ball,' the first from Florida (Pourtales) and Cuba, dredged 

 at 805 fathoms, the second found in various stations in the Gulf of 

 Mexico and West Indies during the "Blake" Expedition. The old 

 Pleurotoma cedo-nulli, Eeeve, likewise is transferred to the same genus. 

 This is supposed to have come from Panama (Cuming). A. orient is, 

 being the first species yet recorded from the Old World, is for that 

 reason alone worthy of description at the present juncture, although 

 none of the five or six examples procured from shell-sand and 

 globigerina-ooze are otherwise than in very juvenile condition. In 

 all probability, when full grown, some sculpture would be present 

 on, at all events, the body-whorl ; and the size would be at least 

 doubled, say 18mm. 



Pletjeotoma trtpanodes,^ n.sp. PI. Y, Fig. 2. 



P. testa fusiformi, albida, eleganter tornata, anfractibus 11-12, 

 quorum apicales 3 J globulares, parvi, vitrei, caeteris spiraliter tornatis, 

 tricarinatis, et liratis, liris cum carinis alternantibus, una carina infra, 

 juxta suturas, duabus infra medium anfractuum, striis indistinctis 

 longitudinaliter conjugatis, ultimo anfractu spiraliter magnopere 

 carinato et lirato usque ad basin, apertura ovata, labro tenui, sinu 

 lato sed non prof undo, canali producta, columella recta. Long. 21, 

 lat. 7 mm. 



J?ai.— Arabian Sea, lat. 18° 58' N"., long. 71° 45' E., 40 fathoms. 



A most refined species, near PI. oxytropis, Sowb., but with more 

 regular angled carinse and alternating lirations. 



Mangilia bathmis,^ n.sp. PI. V. Fig. 4. 



M. testa ovato-fusiformi, utrinque attenuata, solida, alba, anfractibus 

 6, quorum tres apicales perlaeves, vitrei, nitidi, caeteris conspicue 

 graclatis, ad suturas quasi canaliculatis, longitudinaliter oblique 

 crassicostatis, costis apud ultimum anfractum numero circa 14, liris 

 spiralibus, in penultimo circa 6, decoratis, ultimo producto, apertura 

 oblonga, labro paullum incrassato, canali lata. Long. 6, lat. 2 mm. 



J?«J.— Persian Gulf, Gulf of Oman, lat. 24° 58' N., long. 56° 54' E., 

 156 fathoms. 



Of peculiar form, the thickened ribs and terraced whorls being 

 noteworthy. Of very rare occurrence at the above locality. 



1 Bull. Mus. Comp. Zool., xviii, No. 29, pi. xii, fig. 12, and pi. xxxvii, fig. 3. 



^ Tpuirai/(i5Tjs, screw-like. 



3 ^a()^is, a teiTaced flight of steps. 



