76 THE VOYAGE OF H.M.S. CHALLENGER. 



Those on the upper spiral are rather the larger ; the middle of the whorl for about O'l iuch 

 is bare. On the base there are five closely-beaded threads, of which the inmost and 

 strongest defines the umbilicus. Between the outermost and the carina is a broad slightly- 

 sunken furrow. The carina meets the outer lip and appears above the suture. Longitu- 

 dinals — the upper whorls are ribbed, but the ribbing gradually breaks into the double row 

 of paired tubercles, and the link uniting the pairs in the two rows becomes very feeble. 

 There are besides many distant, irregular, loose skin-like puckerings which follow the 

 lines of growth ; they disappear on the spiral threads. The whole surface is further 

 roughened by microscopic flexuous wrinklings. Colour yellowish white on the thin 

 calcareous layer overlying the nacre. Spire high, a little scalar. Apex small and sharp. 

 Whorls 8, of regular increase, a little rounded, angulated at the carina, rather tumid on 

 the base, with a wide umbilicus. Suture angulated and well defined, but a little filled up 

 by the carina of the overlying whorl. Mouth (apparently) perpendicular, semioval. 

 Outer lip well rounded. Pillar-Up a little bent over on the umbdicus, and then advanc- 

 ing rather straight towards the left, angulated and slightly toothed at the point of the 

 base where the umbilical beaded thread joins it. Umbilicus a wide deep funuel, with a 

 deep spiral staircase at the junction of the whorls. H. 0"68 in. B. - 72, least 0"61. 

 Penultimate whorl, (P19. Mouth, height 0'32, breadth 0-32. 



This beautiful species is unfortunately present in only one dead and chipped specimen. The name 

 given to it is expressive of the singular beauty of its sculpture. It is more like Trochus magus, L., 

 than any other species I know, but is obviously very different in all details of form and sculpture. 

 It has some resemblance to Trochus ottoi Phil., but is higher and narrower; that species has a 

 broadly open but immediately contracted umbilicus, which rather resembles a scoop than a funnel ; 

 its whorls are much less tumid above, and are less sculptured ; they slope downwards conically from 

 the suture with only one feeble and feebly tubercled thread between the suture, to which it lies near, 

 and the peripheral thread. 



42. Trochus (Gibbula) zonatus, "Wood (PI. VI. fig. 7). 



Trochus cingulatiis, Miihlfeldt, Mag. d. Gesellsch. Naturf. Freunde, Berlin, vol. viii., 1818, pL iL 

 fig. 11 (but not of Brocclii). 

 zonatus, "Wood, 1828, Index Test. Suppt., p. 221 (ed. Hanley), pi. v. fig. 34. 

 cingulatiis (de novo), Menke, Synopsis Method., pp. 55, 143. 



menkeanus, Philippi, Abb. und Besch., vol. i. p. 91, sp. 5, pi. xxi. fig. 6, and vol. ii. p. 39. 

 zonatus, Krauss, Sixdafrik. Moll., p. 97, sp. 8. 



Philippi, Conch. Cab. (ed. Kiister), p. 287, sp. 372, pi. xlii. fig. 8. 

 „ v. Martens, Siidafrik. Moll, in Jahrb. d. Deutsch. Malak. Gesellsch., 1874, p. 129, 

 No. 97, and p. 142. 

 ,, leaensis, Watson, Prelim. Eeport, pt. 5, Journ. Linn. Soc. Lond., vol. xv. p. 90. 



October-December 1873. Sea Point, Cape Town. 



Habitat. — False Bay and Table Bay, Cape of Gool Hope (v. Martens). 



