HALIOTIS. 121 



over covered with fine closer spiral threads and much finer radiating 

 stria? ; perforations 6. 



The form varies from elliptical to rounded-oval ; the spiral rib of 

 the upper surface is also variable in prominence. There are no 

 radiating lamellae between the spire and the rib, and as usual there 

 is a shallow channel outside of the roAV of holes. The color is 

 between scarlet and brick-red, with irregular, often radiating white 

 patches. The spire is raised and rather prominent. Inside silvery, 

 with red and green reflections ; having a furrow corresponding to 

 the rib of the outside. Columellar shelf narrow, flattened. Holes 

 subcircular, 6 open. 



Length 47, width 34, convexity 10 mill. 



Length 40, width 29, convexity 9 mill. 



Gape of Good Hope. 



H.parva Linn. Syst. Nat. x, p. 780. — Hanley, Ipsa Linn. Conch., 

 p. -113. — Reeve, Conch. Icon., f. 53a, b. — Krauss, Die Siidaf Moll., 

 p. 94. — AYeinkauff, Conchyl. Cab., p. 8, t. 2, f. 11. — Sulculus 

 parvus Ads. — Hallotis canaliculata Lam. Anim. s. Vert, vi, p. 217. 

 — And of Deshayes and Blainville. — Padollus canaliculatw 

 Chenu, Manuel, f. 2748, 2749. — H. vulgaris Blainville, Mai. pi. 

 de princ. no. 2, f. 6. — H. carinata Swains, in Bligh Catal., appendix. 

 p. 2. 



Distinguished by the fine even spiral striation, the strong central 

 rib, and the entire lack of radiating folds or lamellae. 



H. pourtalesii Dall. PI. 22, figs. 27, 28. 



Shell small, of a pale brick-red color, with white dots on some of 

 the spirals, rather elevated, with about two and a half whorls ; 

 apex small, prominent ; holes about twenty-five, of which five remain 

 open, the margins of these rather prominent ; outside the row of 

 holes the usual sulcus is strongly marked ; about midway from the 

 suture to the lines of holes is a raised rib, rather obscure, but 

 differing in different individuals and corresponding to an internal 

 sulcus ; between the central ridges and the suture there are no 

 undulations or transverse ridges of consequence ; sculpture of well 

 marked, rather flatfish, spiral, close-set threads, sometimes with a 

 single finer intercalary thread, overlaid by smaller rather com- 

 pressed transverse ridges, in harmony with the incremental lines ; 

 on top of the spirals the ridges bulge like the threads of worsted on 

 canvas embroidery ; spire situated well forward and with subvertical 



