84 THE VOYAGE OF H.M.S. CHALLENGER 



Shell. — Small, conical, scalar, with rounded base and large umbilicus, sculptured. 

 Sculpture : Spirals — there is a double, tubercled carina, of which the basal one meets the 

 outer lip ; the upper and stronger angulates the whorl about two-fifths from the base ; 

 less than one-fifth from the suture is a shoulder formed by a row of stronger remoter 

 tubercles scarcely connected by a thread. On the base are two feebly beaded threads, 

 another strongly beaded defines the umbilicus, close within which lies another delicately 

 and remotely beaded. Longitudinals — the top whorls are strongly ribbed, but further 

 down these ribs break into tubercles and become disconnected ; but traces of these longi- 

 tudinals remain here and there. The lines of growth are very faint. Colour white, with 

 a pearly lustre. S}rire high, scalar. Apex not fine, rounded, with the inflated 1J embry- 

 onic whorl standing out prominently. Whorls 6, fiat below the suture, angulated at the 

 first spiral, below which the profile line is flatly conical ; it is angulated at the second 

 spiral, and then contracts into the suture below. Suture acutely angulately impressed. 

 Mouth round, angulated at the front of the pillar. Pillar-Up slowly and slightly bent 

 over the umbilicus. Umbilicus open, funnel-shaped, internally scored with minute longi- 

 tudinal ribs. H. 0-25 in. B. 0'21, least 0'18. Penultimate whorl, 0-05. Mouth, height 

 0-1, breadth 0'09. 



The specimen from which I have described this is in bad condition ; but the species is certainly 

 distinct from any other known to me. 



50. Trochus (Margarita) infundibulum, Watson (PI. V. fig. 5). 



Trochus {Margarita) infundibulum, Watson, Prelim. Keport, pt. 4, Journ. Linn. Soc. Lond., vol. xiv. 



p. 707. 



Station 56. May 29, 1873. Lat. 32° 8' 45' N., long. 64° 59' 35" "VV. Off Bermuda. 

 1075 fathoms. Coral mud. 



Station 146. December 29, 1873. Lat. 46° 46' S., long. 45° 31' E. Off Marion 

 Island. 1375 fathoms. Bottom temperature 35 '6° Fahr. Globigerina ooze. 



Animal of a uniform light colour. Foot broad, bluntly pointed behind. Appendages 

 5, probably 6, large, between which the membrane above them is edged with many small 

 ones. 



Shell, — Conical, with a tumid base, carinated, umbilicated, thin, translucent, pearly. 

 Sculpture : Spirals — on the upper whorls 2, on the body whorl 7-8, pretty strong, but fine 

 beaded threads. The first lies remote below the suture, and is sparsely ornamented by 



