new Deep-sea Mollusca. 369 



Pleurotoma [Surcula] profundorum. 



Testa breviter fusiformis, alba, periostraco tenuissimo griseo plus 

 minus induta ; anfractus normales, in medio concavi, inferue ad 

 suturam tuberculati, infra suturam lineis iucrementi angulatis 

 fortibus iustructi, ad angulum carinati, et spiralitei" striati, ulti- 

 mus ad peripheriam oblique tuberculatus, infra convexiusculus, 

 liris transverse leviter obliquis tenuibus instructus,antice rostratus ; 

 apertura angusta, lougit. totius g aequans. 



Longit. 34 millim., diam. 12. 



Hah. N.E. of Maldive Islands, lat. N. 7° 05' 45", long. E. 

 75° 04', in 719 tathoms. 



The labral sinus is broad and rather deep and situated at 

 the suture. One specimen only. Tliis species might be 

 placed in Ball's subgenus Leucosyrinx, wliich, however, is 

 scarcely separable from Surcula. 



Pleurotoma [Surcula) Thurstoni. 



Testa fusiformis, albida, periostraco tenuissimo dilute olivaceo 

 induta ; anfractus normales 10, paulo infra medium angulati, 

 supra concavi, infra suturam tcnuiter plicati, ad angulum oblique 

 et fortius plicati, infra medium spiraliter striati, supra laevea, 

 ultimus antice rostratus, lineis incrementi flexuosis aliisque trans- 

 versis sculptus ; apertura longit. totius | fere aequans ; labrum 

 tenue, superne late et subprofunde sinuatum. 



Longit. 40 millim., diam. 13 ; apertura cum canali 19 longa, in 

 medio 5 lata. 



Hah. Off Trincomalee, Ceylon, in 200-350 fathoms. 



Named after Mr. Edgar Thurston, of the Madras Museum. 

 In general form recalling P. javana (L.). The nodules at 

 the periphery are rather similar, but the tine sutural plicse are 

 wanting in that species. 



Pleurotoma [Surcula?) , sp. 



Hah. Off Trincomalee, in 200—350 fathoms. 



A single immature specimen is all that was obtained. It 

 is shortly fusiform, white, and covered with a very thin peri- 

 ostracum. The v/horls are concave above, acutely tubercu- 

 lated above the suture, finely spirally striated, and marked 

 with fine curved lines of growth. The outer lip is thin, 

 shallow ly sinuated above, curved and prominent in the middle. 

 Anterior canal broad, oblique, slightly recurved. Spire 

 conical, short, acute. 



