BY W. L. MAY. 91 



ODOSTOMIA CRASSICOSTA, Sp. Nov. 



Shell minute, white, solid, short, truncated, boldly 

 ribbed. Whorls 3, plus a smooth, inverted tip. Whorls 

 rounded ; suture deeply impressed, or channeled. About 

 20 strong rounded axial ribs cross the whorls, and bend 

 over into the suture, and disappear on the base. They are 

 separated by deep furrows of about equal width, which are 

 crossed by numerous slightly raised lirae, which do not 

 pass over the ribs, but continue on the base. Mouth 

 ovately pyriform, slightly expanded in front. Columella 

 curved, a little reflected over a narrow umbilicus, and 

 bearing medially a very small, blunt tooth, which is quite 

 invisible from a front view. 



Length 1.7. Breadth 1 mill. 



Type, from 50-70 fathoms, off Port Arthur, with several 

 others; from off Schouten Id., one specimen. It has con- 

 siderable resemblance to 0. oodes, Watson, dial. Report, 

 p. 485, from Cape York, but seems a very distinct little 

 species. 



PI. IV., fig. 20. 



TRIPHOPvA OBLIQUA, Sp. Nov. 



Shell large, very elongated, rugose, yellowish-brown. 

 Whorls at least 30, flattened, broadest at the lower suture. 

 Sculpture : A prominent rounded, smooth pullus develops 

 two strong keels, which continue on two whorls, and are 

 abruptly succeeded by two rows of gemmules, which after 

 8 or 9 whorls pass into the final adult sculpture, wUich 

 consists of three nodular keels, the lower two the strong- 

 est ; the nodules, and their interspaces, form axial ribs, 

 which, being nearly in a line with the spire at first, be- 

 come more oblique as they descend, trending towards the 

 right. There is also a well developed sutural keel, which 

 strongly margins the periphery of the body whorl, and 

 there are two smaller ones on the base. Mouth rather 

 square, produced behind into a tubular canal. 



Length 17. (?) Breadth 3 mill. 



Type, from 50-70 'fathoms, off Port Arthur. No per- 

 fect specimen of this well-marked species has yet been 

 taken, and the figures are from two examples. The apical 

 portion is well preserved, but the mouth is somewhat im- 

 perfect, and the tube may be more produced. This is 

 one of our largest species. The length given is approxi- 

 mate, but from a comparison with several overlapping 

 fragments, is nearly correct. The strong rugose appear- 

 ance, and particularly the very oblique axial ribs, are 

 very striking, and the apex is also a good specific guide. 



PI. IV., fig. 21, lower portion of shell, fig. 21a, apical por- 

 tion. 



