706 



EEV. E. BOOG WATSON O'N THE 



lip. Fillar-lij) depressed upon the umbilicus, then rounded and 

 sinuated, slightly toothed at the point of the pillar. Umhilicus 

 wide and deep, but internally narrowed. H. 0'17. B. 0'13, 

 least 0-1. Penultimate whorl O'OS. Mouth, height 0-07, breadth 

 0-07. 



The peculiarly high narrow spire and the vaulted prickles are 

 very characteristic features of this species. Wlien 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 Pernambuco, 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 infrasutural sinus, and the form of the pillar is also suggestive 

 of JBasilissaj but the form of the mouth is wholly unlike that 

 genus. 



11. Trochus (Margarita) rhtsus, JV. (pvaos, wrinkled.) 



St. II. Jan. 13, 1873. Lat. 38"^ 10' N., long. 9° 14' W. 

 Setubal. 470 fms. GloUgerina-oozQ. 1 specimen (young). 



St. 23. Mar. 15, 1873. Sombrero Island, St. Thomas, Danish 

 West Indies. 450 fms. GloUgerina-oozQ. 1 specimen. 



Sliell. — 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 longitu- 

 dinals remain here and there. The lines of growth are very 

 faint. Colour white, with a ])early lustre. Spire high, scalar. 

 Apex not fine, rounded, with the inflated 1\ embryonic whorl 

 standing out prominently. Whorls 6, flat below the suture, 

 angulated at the first spiral, flat on the contour, angulated at the 

 second spiral, and contracted into the suture below. Suture acutely 

 angulately impressed. Mouth round, angulated at the front of 

 the pillar. Pillar-lip slowly and slightly bent over the umbilicus. 



