360 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [May 20, 



periphery ; base and nucleus ribless ; the whole surface of the shell 

 (except the nucleus) is covered with extremely numerous and close- 

 set spiral stri«, which are discernible only with the aid of a micro- 

 scope : colour glassy : spire rather long, and gradually tapering to a 

 blunt point : suture slight : whorls 6, besides the nucleus, which is 

 spirally twisted and intorted ; the last or body-whorl occupies two 

 fifths of the spire : mouth oval, acutangular above and curved below : 

 outer lip thin : inner lip inconspicuous : umbilicus none, but the 

 base is shallowly excavated. L. 0-075. B. 0.035. 



• Porcupine ' Exp. 1870 : Atl. St. 13. Half a dozen living speci- 

 mens. 



This beautiful little shell may be distinguished by the numerous 

 microscopic spiral striae, as well as by its shape and prismatic lustre. 



,/ 42. Odostomia attenuata ', Jeffreys. (Plate XXVII. fig. 4.) 

 Shell club-shaped, thin, semitransparent, and very glossy : 

 sculpture, long, sharp, and curved longitudinal ribs, from 18 to 20 

 on the last whorl, and with equally broad interstices ; these ribs are 

 not continued beyond the periphery, and in one specimen they nearly 

 disappear on the last whorl ; apex quite smooth : colour whitish, 

 with a faint tinge of yellowish-brown : spire elongated, and gradually 

 tapering to a blunt and apparently truncated point : suture well 

 defined : ivhorls 6, exclusive of the nucleus, which is globular, spiral, 

 and intorted ; the last whorl occupies two fifths of the spire : mouth 

 and lips as in the last species : base sloping. L. 0-125. B. 0-035. 

 'Porcupine' Exp. 1870: Atl. St. 17; Med. 55. 

 Distribution. Gulf of Marseilles ('Travailleur ' Exp.), off western 

 coast of Africa (' Talisman ' Exp.) ; 363-1259 fms. 



^ 43. Odostomia compressa^ Jefifreys. (Plate XXVII. fig. 5.) 

 Shell cylindrical, compressed in the middle of each whorl, rather 

 thick, semitransparent and glossy : sculpture, sharp and straight 

 longitudinal ribs, which commence at the top of each whorl and 

 more or less disappear at the periphery ; their number is about 25 

 on the last whorl ; they are usually of the same breadth as the 

 interstices, but occasionally narrower ; base and apex quite smooth : 

 colour whitish, with a broad but obscure spiral band of reddish- 

 brown in a young specimen : spire turreted, elongated and gradually 

 tapering : suture narrow but distinct : u'horls 10, flattened, con- 

 tracted in the middle of each ; the last occupies about two fifths of 

 the spire ; nucleus twisted : moulh oval, acutangular above, rounded 

 below : outer lip incurved, and flexuous in the middle : imier lip 

 thickened and somewhat expanded : base sloping. L. 0-25. B. 0-075. 

 'Porcupine' Exp. 1870: Atl. St. 17, 36; Med. 40, Beuzert 

 Road. 



Distribution. Gulf of Marseilles (' Travailleur ' Exp.), off the west 

 coast of Africa, C Verd I., and Azores ('Talisman' Exp.), off the 

 Azores (' Challenger ' and ' Talisman ' Exp.) ; 363-1622 fms. 



'■ Atlemialed or narrowed. ' Pressed or squeezed together. 



