302 AXEL A. OLSSON 



smooth; a strong raised ridge just above the ligament occurs on the left 

 valve; mottled with brown externally, lunule brown; hinge normal for the 

 subgenus; pallial sinus ascending and projecting to a point about level with 

 the middle of the posterior adductor impression; margin crenulated except 

 posteriorly; interior colored rose purple. 



A large specimen in the collection of the California Academy of 

 Sciences, collected by Fred Baker at Carmen Island in the Gulf of California, 

 measures approximately: length, 64.5 mm.; height 57 mm.; convexity (both 

 valves), 42.6 mm. (Hertlein and Strong, 1948.) 



This species is related to C. pulicaria (Broderip) but tends to be larger, 

 more rounded, and has much finer sculpture. It is also allied to C. pubera 

 Val. of the Caribbean but is more finely sculptured and has a more rounded 

 outline. 



Range — Gulf of California to Ecuador. Ecuador: Punta Blanca. 



Chionops's pnlicarla (Broderip) Plate 52, figures 4-4c, 5-5a 



Venus pulicaria Broderip, 1835, Proc. Zool. Soc. London, p. 44 Chiripquie and Tumaco. 

 Venus cingulata Lamarck, Sovverby, 1853, Thes. Conch., vol. 2, p. 729, pi. 161, fig. 191.— 



Reeve, 1863, Conch. Icon., vol. 14, Venus, pi. 8, fig. 26. (Not V. cingulata 



Lamarck, 1818.) 

 Chione (Chione) pulicaria (Broderip), Maxwell Smith, 1944, Panamic Marine Shells, 



p. 61, fig. 775. 

 Chione (Chionopsis) pulicaria (Broderip), Hertlein and Strong, 1948, Zoologica, vol. 



33, pt. 4, pp. 184, 185. 

 Chione (Gnidiella) pulicaria (Broderip), Parker, 1949, Jour. Paleont., vol. 23, No. 6, 



p. 583, pi. 91, figs. 9, 13; pi. 93, fig. 7. 



The shell is of medium size, ovate-trigonal in shape, solid, convex, the 

 posterior side decidely longer than the anterior, acuminated at the end. The 

 lunule is of medium size, cordate, well defined by a deeply incised line, 

 sculptured with coarse concentrics, and of a uniform dark brown color or 

 it may be lightly mottled with white and brown. The escutcheon is small, 

 narrow, and restricted largely to the left valve where it is bordered by a 

 larger, outside area, depressed, and more strongly sculptured. On the main 

 surtace of the disk, the sculpture is formed by a series of rather fine, closely 

 spaced, concentric lamellae, each inclined slightly backwards and with 

 small, radial columns engraved on their ventral face, the radial marks less 

 strongly shown in their interspaces. Most specimens are colored lightly, 

 white or cream overlain by a set of brown zigzag lines. The pallial sinus 

 is short but well formed. Ventral margins strongly crenulated. 



Length 51.2 mm., height 44.3 mm., semidiameter 15 mm. (a right valve, 

 Pearl Islands, Panama. 



On large specimens, the concentric lamellae have a tendency to flatten 

 or thin out over the posterior-dorsal slope. 



Range — Gulf of California to southwestern Colombia. Panama: Pearl 

 Islands. Colombia: Tumaco. 



Chionopsis montezuma (Pilsbry and Lowe) Plate 51, figures 2, 2a 



Chione montezuma Pilsbry and Lowe, 1932, Proc. Acad. Nat. Sci. Philadelphia, vol. 84, 



p. 101, pi. 15, figs. 12-14 Puntarenas, Costa Rica. 

 Chione (Chionopsis) pulicaria (Broderip), Hertlein and Strong, 1948, Zoologica, vol. 



33, pt. 4, pp. 184, 185 (in part). 



The shell is ovate-triangular, convex, the anterior and posterior dorsal 

 margins nearly straight, the ventral margin convex. The posterior end is 



