CADULUS-GADILA. 181 



well-marked and slightly subangular or less distinct and gently 

 rounded, tapering rapidly toward both ends ; outline of concave side 

 noticeably convex in the region of greatest swelling. Section of 

 tube a trifle flattened between the convex and concave sides at the 

 equator or throughout. Aperture subcircular, somewhat oblique. 

 Anal orifice rather large, slightly oval, with no noticeable callus 

 within, its edge irregular from breakage, but possibly two lateral 

 nicks (see fig. 7) may be normally present. 



Length 14*3 mill.; antero-posterior diam. at aperture 2*25, at 

 largest 3'33, at apex I/O mill.; lateral diam. at aperture 2'3, at 

 largest, 3'4, at apex 1/1 mill. 



A more slender specimen measures : length 14*6, diara. at aperture 

 2-3 x 2-5, at largest 2'9 x 3*1, at apex 1-2 x 1-4 mill. 



Off Tillamook Bay, Oregon, in 786 fms., bottom temp., 37.3 ; off 

 Cape St. Martin, California, in 218 fms., temp., 43.2 ; off San Luis 

 Obispo Bay, 252 fms. ; off Santa Barbara Is., 414 fms. ; off San 

 Diego, in 822 fms., temp., 39 ; also Gulf of Panama, in 1,270 fms., 

 temp., 36.4 (U. S. Fish Commission). 



A large stout species, much exceeding C. tolmiei, C. clavatus and 

 C. dalli in size, and more swollen and robust than either. The 

 equator is nearer the aperture and more pronounced than in C. tol- 

 miei Dall. The Atlantic forms C. grandis and C. spectabilis Verrill 

 are somewhat similar, but the former is stouter, the latter longer 

 than C. ealifornicus. It varies considerable in inflation, some speci- 

 mens (figs. 7, 8) being decidedly less swollen than that selected as 

 type (figs. 5, 6). 



The type specimens are No. 107,698, U. S. Nat. Mus. 

 <J. TOLMIEI Dall. PI. 34, figs. 3, 4. 



Shell thin, polished, slightly bluish-white, a trifle translucent, 

 rather arcuate ; moderately swollen, the greatest diameter contained 

 about 5 times in the length, situated about at the anterior third, 

 thence tapering at first gradually and then rapidly to the apex, 

 only slightly contracting toward the aperture; convex side strongly 

 and evenly arched, opposite outline straight along the anterior half, 

 concave posteriorly. Tube a trifle compressed vertically in the 

 middle and anteriorly ; sculpture none, or only of obscure, incre- 

 mental lines. Aperture oblique, nearly circular ; anal orifice sub- 

 circular, simple. 



Length 10*7, autero-posterior diameter at aperture 1*65, at greatest 

 bulging 2'0, at apex 0'77 mill.; lateral diam. at aperture T72, at 

 greatest 2'1, at apex 0'72 mill. 



