MOLLTJSCA OF THE ' CHALLENaER ' EXPEDITIOlSr. 339 



shell is a coronal of folds forming ridges and furrows of about 

 equal strength ; these extend over the top and into the hollow 

 crown. Spirals — round the top, harshly scoring the coronal, are 

 4 or 5 deep, but not broad, sharp-cut furrows, parted by flat 

 surfaces of about twice their breadth ; below these, to a fourth 

 of the length, there are distant furrows so obsolete as to be 

 almost invisible ; below this the whole surface is superficially 

 scratched with delicate sharp-cut fretted furrows parted by 

 broadish flat intervals. Colour translucent white. Mouth the 

 entire length of the shell, being considerably produced poste- 

 riorly, where it is slightly enlarged ; in the middle it is narrow, 

 the two sides being almost perfectly parallel, in front it is 

 elongately oval ; in its entire shape it resembles a spoon. Whorls 

 4, but the earlier ones are so deeply sunken, and the hole in the 

 crown (where alone they are visible) is so small, that it is difficult 

 to count them ; the apex is papillary. Suture slight. Outer lip 

 rises straight from the crown, with a slight inclination in towards 

 the centre, is narrowly rounded above, and advances straight for 

 about two thirds of the shell's length, at which point it is slightly 

 expanded, and then becomes somewhat patulous ; it sweeps rather 

 freely round to join the pillar. Top small, oblique, harshly 

 radiatingly striate and deeply narrowly impressed. Inner lip 

 long and straight, slightly convex in front, oblique and slightly 

 concave on the pillar, which is bluntly toothed in front, and has 

 a very narrow scarce patulous prominent edge with a minute 

 furrow behind it. L. 0"18. B. 0"06. B. of mouth at same 

 place, 0-019. 



This sjDCcies, whose thin and famished look suggested the name 

 chosen, belongs to the group of which the Mediterranean 

 Z7. striatula, Forb., may be taken as a type, though in that the fea- 

 tures attributed to the subgenus &o (oi Gylichnci) are much more 

 strongly developed. Compared to this species of the ' Challenger,' 

 Cylichnajljiensis, E. Sm., is broader, not squarely truncate above, 

 and not so plicate round the top of the body. U. phiala, A. Ad., 

 from Japan, is not nearly so long and narrow, and is more 

 cylindrical. Oylichna dectissata, A. Ad., which is like in sculpture, 

 ia shorter, less cylindrical, and the outer lip rises much higher 

 behind. G. pyrmnidata, A. Ad., which is puckered above, is 

 much less cylindrical and is smooth in the body. 



