588 



REV. R. BOOG WATSON ON THE 



sharply projectiug, flexuous, defiaing the lines of growth ou 

 the upper whorls, but these become very faint on the later 

 whorls. Colour pure white with pearly translucency when 

 fresh, but weathering opaque with a pearly gleam through the 

 calcareous surface -layer. Spire high and conical, in some 

 specimens a little depressed. Apex small, rounded, slightly 

 tabulated, with the 1| embryonic whorl projecting, round, 

 glossy, but slightly roughened. Whorls 8, of slow and 

 regular increase, angulated above, sharply carinated, inflated 

 on the base, which is also slightly angulated by the third infra- 

 carinal spiral. Suture only doubtfully traceable (under the 

 microscope) in the middle of the sutural spiral. Mouth per- 

 pendicular. Outer lip thin and sharp, not patulous, not 

 descending, with an open not deep angular sinus near the 

 suture, from which the line of the edge runs outwards uninter- 

 rupted across the second spiral, and forms a round projecting 

 point, retreating again so as to form a second sinus, smaller 

 and sharper, in the line of the basal carina, from which it again 

 runs outwards into a rounded point in the exterior basal fur- 

 row, and from this again retreats, sharply changing its direc- 

 tion on the fifth spiral, and then again retreating, as before, to 

 the sixth spiral, where it forms a third, open, obtuse-angled 

 sinus, and then passes in regularly to the centre, Fillar-lip 

 twisted, w^ith a deep rounded sinus above, a strong twisted tooth 

 at about two thirds of its length, another narrower rounded 

 sinus below, and a sharp tooth at the point. The pillar is 

 strengthened by a pad, which is spread out on the base so as to 

 cover the seventh (counting from the suture) spiral, and enve- 

 lopes the pillar so as to leave a minute furrow behind it, but 

 ceases at the pillar-tooth. Umhilicus completely closed (but 

 in some young specimens presenting a minute hole, see var. 

 lineata, W.). H. 0-2. B. 0-14, least 0-12. Penult, whorl 

 0-04. Mouth, height 0-07, breadth 0-06. 



Mr. Gwyn Jeffreys tells me {in litt., Nov. 15, 1878) that he has 

 got the operculum of this species, and that it " is ear-shaped, 

 very thin, paucispiral (having only two whorls); the spire very 

 small, excentric, and placed on the columellar side, thus resem- 

 bling somewhat that of Solarium and Adeorhis " — a feature which, 

 according to Quoy and Gaimard,is shared by Euchelus, Philippi's 

 subgenus of Trochus. 



To the young specimens from Pernambuco, var. lineata, W., I 



