192 CADULUS-GADILA. 



Length 7, diam. at aperture 0'625, at greatest bulging 0'934, at 



apex 0"25 mill. 



Length 7, diam. at aperture 0*5, at greatest "75, at apex 02 milL 

 Panama Bay, in 26 and 51 fms., mud ; off Guaymas, Mexico, in 



20 fms. ; in the Pacific off Lower California, 'Albatross' Sta. 2,830, 



lat. 23° 33', long. 110° 37', in 66 fms. ; near Cerros Id., 26 fms. (U. 



S. Fish Commission) ; Mazatlan (Cpr.). 



Dentalium corrugatum Cm., Cat. Mazatlan Shells, p. 189 (1857), 

 a very young shell. Not D. corrugatum Gay, 1854. 



This species is extremely similar to C. dentalinus (Guppy) from 

 the Jamaican Oligocene, but the concentric wrinkles are perceptibly 

 more crowded and less oblique in the living than in the fossil form. 

 Compared with the Antillean C. acus Dall, our species or variety is 

 decidedly stouter and more curved, with stronger constriction at 

 the mouth. 



Types, No. 122,795 U. S. Nat. Mus. 



The shells from off Guaymas and Cerros Island are the size of 

 the types, but more annulated. 



Var. 7najor P. & S. PI. 36, figs. 28, 29, 30. 



A larger form of this species occurs off Lower California at Station 

 2,880 of the Fish Commission, in 66 fms. sand. The larger speci- 

 mens are annulated for a shorter distance from the apex than in the 

 Bay of Panama types. Three specimens (illustrated) measure: 



Fig. 28, length 10'37, diam. at aperture 1'12, at greatest 1*72, at 

 apex 0'75 mill. 



Fig. 29, length 8*62, diam. at aperture TO, at greatest 1"37, at 

 apex 0"37 mill. 



Fig. 30, length 8"12, diam. at aperture 0*87, at greatest ri2, at 

 aj)ex 0"44 mill. 



The specimens of this form are No. 96,570, U. S. Nat. Mus. 



The dimensions of Carpenter's Dentalium corrugation, length 

 1*25, greatest diam. 0'25, apical diam. 0'125 mill., indicate, as Car- 

 penter says, a very young specimen. One only was found ; the 

 concentrically wrinkled surface being its most remarkable character. 

 We have little doubt that it is the very young of Cadulus panamen- 

 sis, which is also annulated ; but in any case the name is preoccu- 

 pied for a Chilian Tertiary species of the group of D. ceras, and will, 

 therefore, be dropped. Carpenter's description here follows : 



" D. corrugatum. Shell whitish-corneous, subdiaphanous, little 

 arcuate, slender. Surface concentrically, irregularly corrugated,. 



