MAZATLAN UNIVALVES 393 



460. DEILLIA EUDIS, Sow. 



Pleurotoma rudis, Sow. Proc. Zool. Soc. 1833, p. 134. Mull. 



Syn. Nov. Test. Viv. p. 109. JRve. Conch. Ic. pi. 7, sp. 53. 



C. B. Ad. Pan. Shells, p. 146, no. 181. 

 Crassispira (Drillia) rudis, H. fy A. Ad. Gen. i. 91. 

 Comp. P. excentrica, Sow. loc. cit. Eve. loc. cit. sp. 58. 



(Drillia e.) H. $ A. Ad. Gen. i. 90. 



In a genus, the discrimination of whose species rests on 

 minute details of sculpture, the figures in the Conch. Ic. are of 

 but little help. The two shejls from the Mazatlan boxes, with 

 others obtained from a shop, probably from the same collection, 

 agree in some points with each species, but are referred to 

 D. rudis by Mr. Cuming. They are of a dull black, without 

 white spots, with the upper keel nodulous in the upper whirls, 

 a row of costal tubercles abnormal^ shewing at the suture, 

 with spiral lines faintly nodulous below ; the whole surface 

 minutely spirally striulated. more coarsely in the region of 

 the notch ; the last whirl descending and then rising, making 

 the axis excentric ; aperture ending in a notch with a very 

 stout callosity rising above : labrum thin, slightly incurved 

 and serrated, with a strong rib behind ; labium distinct. 

 Long. 1*1, long. spir. '6, lat. '48, div. (upper whirls) 48. 

 Hob. Monte Christi ; under stones ; Cuming. Mazatlan ; 



extremely rare ; L'pool Col. 



Tablet 1890 contains one specimen. 



^- 461. DETLLIA ATERRIMA, Sow. var. MELCHEESI. 



Pleurotoma aterrima, Sow. Proc. Zool. Soc. 1833, p. 137. 

 Mull. Syn. Nov. Test. Viv. p. 113. Rve. Conch. Ic. pi. 12, 

 sp. 100. C. . Ad. Pan. Shells, p. 138, no. 163. 



Crassispira (Drillia) aterrima, H. <$f A. Ad. Gen. i. 90. 



?=P1. maura, Vol. in Kien. Icon. Condi, p. 59, no. 37, pi. 23, 

 f. 1. (non Sew.) 



=P1. Melchersi, Mice, in Zeit.f. Mai. 1851, p. 20, no. 91. 



? + Pleurotoma discors, Sow. Proc. Zdol. Soc. 1833, p. 137. 

 Mull. Syn. Nov. Test. Viv. p. 113. Eve. Conch. Sijst. pi. 235, 

 f. 14: Conch. Ic. pi. 6, f. 38. 



Var. ?=P1. atrior, C. S. Ad. Pan. Shells, no. 164, pp. 138, 308. 



= Pleurotoma rustica, P. P. C. Cat. Prov. t non Sow. 

 It is fortunate if Kiener's species, described from a specimen 



brought from Mazatlan by M. Botta, is not needed, as the 



