220 MAZATLAN UNIVALVES 



antibus pictd ; aperturd elongatd, obscure trilobatd ; pagind 

 internd nitente, cinereo-albidd, inaculis externis plus minusve 

 monstr antibus, callositate marginem versus rubro-purpureo : 

 cicatrice musculari irregulari, intus callosd, antice punctulatd ; 

 margine acuto, haud crenulato, testa juniore castaneo punctato. 



Only two specimens were found of this singular little shell ; 

 the younger one of which, though the most highly coloured, 

 is diseased within, and displays neither the lurid colour of 

 the faecal callus, nor the punctures on the anterior part of 

 the general callosity which fills up the space between the 

 irregularly jagged muscular scar and the region of the hole. 

 It most resembles F. catillus, IRve. The external surface is 

 loose and rough. Long. '7, lat. antice '3, postice '43, alt. '24, 

 dtv.105 by 80. Hole '14 by "04. 

 Hob. Mazatlan ; extremely rare ; IS pool Col. 



Tablet 1070 contains the larger specimen. 



SUBGENUS GLYPHIS. 



Animal margine palliijimbriatd, marginem lestce superante. 



Testa superficie cancellatd, margine crenulato, callositate 

 s&pe truncatd, interdum laminatd ; testa juniore Hirnul&formi, 

 spird in aperturd crescente absorptd. 



Lucapina, IT. 8f A. Ad. Gen. i. 447, (maxima pars) : non Gray. 



279. GLYPHIS IN^EQUALIS, Sow. 



Fissurella insequalis, Sow. Proc. Zool. Soc. 1834, p. 126 : - 



Conch, III. no. 36, f. 45. Eve. ConcL Ic. pi. 7, sp. 50. 

 Lucapina insequalis, H. fy A. Ad. Gen. i. 447. 

 + Fissurella pica, Sow. Proc. Zool. Soc. loc. cit: Conch. HI. 



no. 37, f. 32, et var. f. 33. Rve. Co%ch. Ic. <pl. 7, sp. 49. 



Mke. Zeit.f. Hal. 1847, p. 186, no. 39. 

 Lucapina pica, H. fy A. Ad. Gen. i. 448. 



The extreme forms of this species are very dissimilar : the 

 one being very inequilateral, with a long narrow trilobed slit, 

 and sharply truncated bicuspid callus within : the other sub- 

 sequilateral with a nearly circular hole, and the callus not 

 truncated. The specimens with an oval hole are F. pica, Sow. 

 and the subsequilateral form is figured in the Conch. III. as 

 F. pica, var. Between the extremes, there is every gradation, 



