EEPOETON THE GASTEKOPODA. 91 



55. Trochus (Margarita) strcptophorus? n. sp. (PI. XVII. fig. 4). 



Station 214. February 10, 1875. Lat. 4° 33' N. Long. 127° 6' E. South-east of 

 Philippines. 500 fathoms. Blue mud. Bottom temperature 41° - 8. 



Shell. — Ivory white, thin, conical, rounded at the periphery, umbilicated, sculptured, 

 and rough on the upper whorls. Sculpture: the upper whorls are dull, rough, and reticu- 

 lated, being crossed by obbque close-set riblets, scored by 7 or 8 fine round threads ; the 

 riblets gradually degenerate into puckerings, which die out in the course of the penulti- 

 mate whorl ; a necklace of little tubercles near the top of the puckerings becomes on this 

 whorl double or treble, the tubercles being at the same time horizontally elongated ; in 

 this whorl too a very obtuse feeble tubercled carination appears in the middle of the 

 whorls ; both this keel and the subsutural necklace die out toward the mouth ; the edge 

 of the umbilicus is angularly keeled ; outside of the keel is a strongish, but depressed 

 thread ; besides this stronger sculpture the whole surface is scored with very fine lines of 

 growth and still more microscopic spiral scratches. Colour white, dead above, and with 

 the gloss and beauty of ivory below, where a faint pearly nacre gleams through. Spire 

 somewhat raised, scalar. Apex small, mammillated, but prominent. WJwrls 6^, high and 

 convex, more or less angulated above the periphery, of regular but rapid increase ; the 

 last large, with a round but slightly flattened base, and with a large marginated funnel- 

 shaped umbihcus, within which the lines of growth are very strong. Suture strong, 

 marginated. Mouth largish, round. Outer lip thin, bevelled off from the inside to a sharp 

 edge, nacreous within. Inner lip strong, concave, patulous, thickened and angulated at 

 point of the pillar where the umbilical keel joins it. Umbilicus funnel-shaped, pervious ; 

 a deeply marked suture coils up within it. H. 0*46 in. B. 0*46. Penultimate whorl, 

 height 0-14. Mouth, height 0'25, breadth 0-23. 



This is a singularly beautiful shell. It is connected in a general way with the group to which 

 Troc/ius (Oxystele) eiospira, Dall. (Proc. Zool. Soc. Lond., 1883, p. 98, pi. xx. fig. 6), belongs. In 

 that species the umbilicus is large when the shell is young, and fills up entirely when the shell is 

 full grown. 



56. Trochus (Margarita ?) scintillans, Watson (PL V. fig. 2). 



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



p. 712. 



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

 Island, West Indies. 390 fathoms. Pteropod ooze. 



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

 1075 fathoms. Coral mud. 



1 er%irra<f>6soc t wearing a necklace. 



