MOLLTJSCA OP THE ' CHALLENGtER ' EXPEDITION. 329 



patulous, and obliquely truncate backwards; iu the middle it is 

 sligbtly contracted. Top : tbe whole upper part of the shell 

 contracts, and the spire is roundly conical and subscalar, with 

 the glossy round papillary apex rising slightly above all : it is 

 scored with the sutural canal, which is narrow and not deep, but 

 well defined by the sharp keel which lies below it. Inner lip : 

 there is a thick prominent labial pad ; the curve of the body is 

 convex, and so passes on regularly to the point of the pillar, 

 which is very oblique and carries a strong, twisted, oblique, 

 longitudinally furrowed tooth ; between this tooth and the body 

 is a very small furrow. H. 0'22. B. 0"1. B. of mouth at 

 same place, 0"02. 



This species a good deal resembles, not the U. tti^rritzis, Moll., 

 but Sowerby's figure of that species in the ' Thesaurus,' pi. cxxi. 

 f. 28. In perfectly fresh specimens the spiral furrows, which 

 I have described as very faint, may be distinct ; but in the ten 

 ' Challenger ' specimens they are only traceable with certainty 

 near the edge of the labial pad. U. canaliculatus, Say, is a much 

 smaller and stumpier form, much broader above, with a minute 

 apex turned over on its side. 



4. IJteictjlus (Toenatusta) aratus, n. sp. 



St. 188. Sept. 10, 1874. Lat. 9° 59' S., long. 139° 42' E. W. 

 of Cape York, ofi" S.W. point of Papua. 28 fms. 



Shell. — Small, oblong, truncated at the toj), rounded in front 

 but not truncated, with whorls sharply angulated above and 

 furrowed spirally from end to end *, a channelled suture, a 

 papillary apex, a longish, concave, toothed, and furrowed pillar, 

 and a small mouth. Sculpture. Longitudinals — the lines of 

 growth are very feeble. Spirals — from end to end the shell is 

 scored with small but distinct furrows, which on the front of the 

 shell are rounded, but above are sharper, shallower, and fretted ; 

 they are parted by flattish surfaces of double their width in front, 

 but much more than this above, where the furrows are slighter : 

 round the top of each whorl runs a sharp up-standing keel, 

 within which lies the deepish and narrow, but at bottom 

 rounded, sutural canal. Colour ivory-white, with a dull gloss. 

 Mouth barely shorter than the shell, narrow, curved, slowly 

 enlarging, elongately pear-shaped. Whorls barely 8. Ou,ter 



* Hence the name. 



