EEPOET ON THE GASTEEOPODA. 85 



longitudinally produced, high and pointed, tubercles ; it forms a shoulder on the whorl. 

 The second projects strongly and sharply at the periphery and forms the carina ; it and 

 those below are delicately fretted with close-set small beads. The third, which meets the 

 outer lip, lies within the contraction of the base. The last two are closer than the rest, 

 which, however, are sometimes brought closer by the additional thread which appears among 

 them. The one which defines the umbilicus is more sharply beaded than the rest. Longi- 

 tudinals — below the suture and near the umbilicus the surface is sharply but delicately 

 puckered, and these puckerings, strong in the early whorls, are in the later faintly continued 

 across the whorls as lines of growth. Colour yellowish white, with a brilliant nacreous 

 sheen shining through the thin superficial calcareous layer, which becomes more opaque in 

 drying. Spire high, scalar. Apex minute, flattened, with the minute bulbous embryonic 

 l£ whorl projecting on one side. Whorls 8, of rapid increase, rounded, but. angulated by 

 the projection of the spirals, very tumid on the base. Suture linear, but strongly defined 

 by the contraction of the suprajacent whorl and the flat shoulder of the one below. Mouth 

 very slightly oblique, round, but on the pillar flattened, and at the point of it angulated 

 slightly ; nacreous within ; across the body there is no pad, but the shell is eroded, and 

 this erosion has the appearance of a thin callus. Outer lip thin, not descending. Pillar- 

 lip slightly patulous, bending flatly over the umbilicus, and then advancing in a straight 

 line to the point of the pillar, where it is slightly angulated just where the beaded umbilical 

 spiral ends. Umbilicus funnel-shaped, rather open, but a good deal contracted within, 

 sharply scored with the lines of growth. Operculum yellow, horny, very thin, of 7 to 8 

 whorls. H. 0-81 in. B. 0"65, least 0'59. Penultimate whorl, 0-2. Mouth, height 0*37, 

 breadth 0-35. 



This beautiful species, of very singular aspect, recalls in a very general way the form of Turcica 

 monilifcra, A. Ad., but diners from that in its rounded contours, strongly contracted suture, umbilicus, 

 and straight untoothed pillar. It resembles in form Margarita aspccta, A. Ad., but that is less 

 tumid, is carinated, its umbilicus is much smaller, the spirals are many more, and they are not 

 tubercled. 



It is very like Trochus ottoi, Phil., a fossil from Messina, lately taken alive in abundance by 

 Professor Verrill off the New England coast in 115 to 500 fathoms, and published by him as Margarita 

 regalis. Trochus iufimdibulum may after all be only a variety, but compared to that this is larger, 

 higher in proportion to breadth, has the base much more tumid, and the longitudinals far weaker. In 

 Trochus ottoi, Phil., these longitudinals are very strong, and make sharper, higher, crisper nodules on 

 the spirals ; that species, too, has not the subsutural flat with its radiating bars and its border of 

 tubercles, and has not the spiral uniting that first row of tubercles. As to the intra-umbilical spirals, 

 they vary astonishingly. Dr Gwyn Jeffreys writes (January 4, 1882), " I quite agree with you that 

 your Trochus infundilulum is a different species from Trochus ottoi, Phil., the Margarita regalis, Verr. 

 and Sm." Philippi says that his species is " simiUimus " to Turbo cinereus, Couth., " qui cingulis 

 transversis elevatis pluribus nodulisque minus distinctis unice differt" (Enum. ii. 227). I confess 

 that I fail entirely to see the resemblance. 



