EEPOET ON THE GASTEEOPODA. 83 



Station 24. March 25, 1873. Lat. 18° 38' 30" N., long. 65° 5' 30" W. Off Culebra 

 Island, West Indies. 390 fathoms. Pteropocl ooze. 



(?) Station 120. September 9, 1873. Lat. 8° 37' S., long. 34° 28' W. Off Pernam- 

 buco. 675 fathoms. Red mud. 



Shell. — Small, conical, with a high spire and a tumid base, a round mouth, and a deep 

 umbilicus, and covered with sharp prickles. Sculpture: Spirals — there are several small 

 threads, two of which, of equal strength and prominence, angulate the whorls — one at the 

 basal contraction, the other about half-way up the whorl ; on the base they are somewhat 

 closer set. The outer lip does not meet the carinal thread, but the one below. Longitu- 

 dinals — the whole surface is crossed by close-set, slightly oblique narrow laminse, which, 

 in crossing the spirals, rise into sharp vaulted prickles whose faces are turned towards the 

 mouth. Colour white, with a pearly lustre. Spire very high. Apex minute, with the 

 small embryonic 1^ whorl rising from a minute flat. Whorls 6^-, angulated and narrow 

 in the spire, but the last inflated and expanded. Suture deeply impressed, somewhat 

 depressed, and very strongly defined. Mouth perpendicular, round, slightly pointed on 

 the base, and angulated at the upper carina. Outer lip sharp, advancing far across the 

 body towards the pillar-lip. Pillar-lip depressed upon the umbilicus, then rounded and 

 sinuated, slightly toothed at the point of the pillar. Umbilicus wide and deep, but inter- 

 nally narrowed. H. 0-17 in. B.0- 13, least 0-1. Penultimate whorl, -03. Mouth, height 

 0-07, breadth 0"07. 



The peculiai-ly high narrow spire and the vaulted prickles are very characteristic features of this 

 species, none of the specimens of which are adult. When full grown there would probably be an 

 additional whorl, which would add a broad base to the high narrow spire. There seems to be some 

 variation in the number of the spirals. I have put a query to the specimens from Pemambuco, 

 because, though identical in other respects, the embryonic whorls are slightly larger and more tumid. 

 The curves of the mouth-edge have some suspicion of an infra-sutural sinus, and the form of the 

 pillar is also suggestive of Basilissa, but the form of the mouth is wholly unlike that genus. 



49. Trochus (Margarita) rhysus, 1 Watson (PI. V. fig. 4). 



Trochus (Margarita) rhysus, Watson, Prelim. Eeport, pt. 4, Journ. Linn. Soc. Lond., vol. xiv. 



p. 706. 



Station II. January 13, 1873. Lat. 38° 10' N., long. 9° 14' W. Off Setubal. 470 

 fathoms. Green mud. 



Station 23. March 15, 1873. Lat. 18° 24' N., long. 63° 28' W. Off Sombrero Island, 

 West Indies. 450 fathoms. Pteropod ooze. 



1 guffo'f, wrinkled. 



