1890.] MARINE MOLLUSCA OF ST. HKLENA. 269 



T. Conry at Ascension, and presented by him to the British 

 Museum, has, however, tubercles as in R. ccelata. The number of 

 the nodules seems to be very variable, and a character of no specific 

 importance. With this species may also be united R. ponderosa, 

 Reeve, the locality of which was unknown to its author, and some 

 shells labelled R. quercina, Morch \ in Cuming's collection, said 

 to have come from Guinea, evidently belong to the same species. 

 As I have been unable to consult the work of Schrciter, referred to 

 by Morch, who gives no description of his species, I cannot say 

 whether these specimens are correctly identified. They are peculiar 

 in having the nodules on the upper whorls as in typical specimens. 



Ranella thom^, d'Orbigny. 



Hab. St. Thomas {cC Oriigny) ; Madeira (TFatson) ; Canary 

 Islands (' Challenger') ; Cape Verde Islands {Brit. Mus.) ; Mauri- 

 tius {Rnbillard). 



D'Orbigny's description of this species (Sagra's Hist. Cuba, 

 Moll. vol. ii. p. 164) was based upon an old dead specimen, entirely 

 devoid of colour, now in the British Museum. In fresh examples 

 the aperture is tinted with pale rose, and the varices and spiral 

 ridges are irregularly spotted and dotted with brown. The enlarged 

 figure in the above-mentioned work (pi. xxiii. fig. 23) is not at all 

 good. The labrum is not so bulging, the granules are not so bead- 

 Hke, the body-whorl is more constricted below, the varix on the 

 left, and the basal canal is directed to the right and not to the left. 

 The largest specimen in the Museum is from St. Vincent, Cape 

 Verde Islands, and measures 22 miilim. in length. 



This species also occurs at tlie Mauritius, and has been named 

 R. bergeri-. This distribution supports Tryou's opinion, that 

 R. tho7nce showlA be considered to be the same as R. rhodostoma, and 

 indeed, excepting that the brown dotting is more conspicuous and 

 the colour of the aperture different, there ig little to found specific 

 distinction upon. 1 cannot, however, agree with that author in 

 considering R. cruentata and R. rhodostoma forms of one and the 

 same species. 



Natica TURTONi. (Plate XXI. figs. 14, 14 a.) 



Testa globosa, late mnbilicnta, rufescens, plus minus radiatim 

 strigata, zonis quatuor albis, maculis saturate fusco-rufs, 

 quadratis, interruptis, cincta, striis incrementi, adsuturam leviter 

 plicatis, sculpta, epiderniide decidua, sublamellata, induta; 

 anfractus 4-5, celeriter accrescentes, conveoci, suiiira profunda 

 sejuncti, ultitmts magnus, aperturum versus leviter expansus vel 

 tubiformis ; umbilicus al bus, magnus, callo mediocriter tenui in 

 medio instructus ; apertura dilatata, semicircularis, intus albida, 

 coloribus externis leviter conspicuis. 



Diam. maj. 19 miilim., min. 14, alt. 18. 



» Cat. Conch. Yoldi, p. 106. 



- Canefri, Mem. Soc. Malac. Belgique, 1880, vol. xy. p. 50, pi. 2. figs. 1, 2. 

 Proc. Zool. Soc— 1890, No. XIX. 19 



