146 



I do not place much value on the outward form, sculpture, and size 

 of these Cyclotus, and, wanting the opercula, regard the classification 

 of them as very difficult ; I will, however, proceed to the more particular 

 description of each species and variety as I find them in my own 

 private cabinet, taking them in the order already mentioned. 



§1. 



C. corrugatus, Sow. Proc. Z. S. 1843, pp. 29, 30. 



Sowerby's entire description is, "C. testa orbiculata, subdepressa, 

 crassiuscula, albida, apice rufescente; epidermide tenui, fusca, induta; 

 spirula, subprominula, acuminatiuscula, ; anfractibus quinque, rotun- 

 datis, transversim striatis et corrugatis ; sutura distincta, apertura 

 circulari, subeffusa, superne angulata, et in canalem inconspicuam 

 desinente ; peritremate tenuiusculo, margine acutiusculo, latere um- 

 bilicali incrassato ; umbilico magno, margine crenulato, intus trans- 

 versim striato. Operculo testaceo, extus lamina elevata, convoluta, 

 intus corneo, polito." 



C. corrugatus, Pfr. Cat. Phan. p. 13. 



Shell subturbinate-depressed, solid, regularly all over angularly 

 wrinkled, white, with a deciduous fulvid epidermis ; spire short, 

 reddish, rather acuminate ; whorls 5, convex, the last one cylindrical, 

 nearly flat beneath, with a nodulous ridge around the umbilicus, which 

 is open, and of a middle size ; aperture a little oblique, nearly circular, 

 with a slight angle above, inside whitish ; peristome straight, blunt ; 

 its margins joined into an angle, which often is doubled ; right mar- 

 gin slightly sinuate ; left margin shortly affixed to the penult whorl. 

 Operculum concave externally, with 9 very narrow whorls, the mar- 

 gin of which is dilated into broad, spiral, raised, somewhat expanded 

 laminse. Height 14, greatest breadth 22, least breadth 19 mill. — Cat. 

 Phan. p. 13. 



C. corrugatus, Chitty. 



The shell I adopt as C. corrugatus I describe as " depressed-tur- 

 binate : colour blueish-white, with an epidermis of rich red-brown 

 and yellowish-brown ; just below the suture and apex, rich red-brown; 

 salmon-colour tinge within the aperture. Sculpture, the 3f upper 

 whorls, excepting the nuclear apex, with the lines of growth strongly 

 but finely defined, without wrinkles. Thence the lines of growth 

 become coarser and coarser throughout the remainder ; coarser and 

 coarser wrinkles diagonally from right above to left below on the 

 penult whorl, the wrinkles gradually assuming a zigzag form, till 

 they become very coarse at the periphery of the last whorl, and then 

 eccentric curvilinear grooves which terminate and are deepest, but 

 are not tooth-marked at the umbilical keel, which is well raised, 

 the terminating fourth part of the last whorl becoming compara- 

 tively smooth. Spire, moderately elevated, with convex outlines. 

 Whorls, b\, moderately rounded, rather flattened above, and spread- 

 ing below, with moderate suture ; the terminal half of the last 



