MAZATLAN UNIVALVES 229 



287. UVANILLA INEBMIS, Gmel. 



U. t. " U. olivacece" simillimd; sed sculpturd fortiore, "rugis 

 in spird distantioribus ; lined granularum internd in basi vix 

 monstrante ; regione umbilicali albd, cavitate profundd, carind 

 spirali acutd circumeunte, extus vix excavatd ; callositate tenui 



Trochus inermis, Gmel. p. 3576, no. 62. Schroet. EM. vol. i. 



p. 719, no. lOO.Dilhv. Descr. Cat. vol. ii. p. 787, no. 67. 



Lam. An. s. Vert. vol. iv. p. 127, no. 17. Kien. Icon. Conch. 



pi. 14, f.2, 2 a. 

 = Trochus olivaceus, Phil, in Zeit. f. Mai. 1848, p. 188: non 



Grray in Wood. 



This shell, which was brought in some abundance by Capt. 

 Kellett, is not the T. olivaceus, Wood, as Phil, seems to have 

 supposed. There can hardly be a doubt that it is the species 

 figured by Kien. and therefore, it is presumed, of Lam. 

 Whether it be that of the Linnsean writers, can scarcely be 

 determined, when the differences are so slight. 



It exactly remembles U. olivacea in almost all respects : 

 but has coarser, more distant rugsD on the body of the whirls ; 

 and in the umbilical region is white, more resembling U. un- 

 guis. Base with the inner row of granules scarcely developed : 

 umbilicus deeply scooped, covered with a thin diffused callus, 

 bounded by a sharp spiral ridge, scarcely scooped outside. 

 The young shell has a fine keel in the place of the inner row 

 of nodules, marked off by two faint spiral grooves, on the 

 medial portion. Whether it be really distinct from U. oliva- 

 cea must await a knowledge of the operculum, and a compari- 

 son of additional specimens. The smallest sp., of 6 whirls, 

 measures long, (apex to basal wing) "86, lot. *98, div. 80. 

 Hab. Mazatlan ; 2 young sp. only j Lpool Col. 



Tablet 1096 contains the youngest (most characteristic) sp. 



288. U VANILLA UNGUIS, Mawe. 



Trochus unguis, Mawe, in Wood Ind. Test. Suppl. p. 16, no. 2, 

 pi. 5. Eve. Conch. Syst. vol. ii. p. 165, pi. 217, f. 6. Kien. 

 Icon. Conch, pi. 13, f. 1 (max.) 



Turbo unguis, Desh. in Lam. An. s. Vert, vol ix. p. 224, no. 42. 



= Turbo digitatus, Desk. Mag. de Gudr. 1841, pi. 36. 



= Trochus amictus, Vol. Voy. Venus. 



June 1856. , 



