PANAMIC-PACIFIC PELECYPODA 189 



Carditamera (Carditamera) radiata (Sowerby) Plate 26, figures 1-lc 



Cardita radiata Sowerby, 1833, Proc. Soc. London for 1832, p. 195. — Reeve, 1843, Conch. 



Icon., vol. 1, Cardita, pi. 1, fig. Sa. 

 Lazaria radiata Sowerby, H. and A. Adams, 1858, Gen. Rec. Shells, vol. 2, p. 489; 



vol. 3, pi. 116, figs. 4, 4a. 

 Lazaria observa Morch, 1861, Malak. Blatter, bd. 7, p. 199. (Proposed for Re«ve, pi. 



1, fig. 5a). 

 Glans radiata (Sowerby), Maxwell Smith, 1944, Panamic Marine Shells, p. 56, fig. 



692J (intext 692U). 

 Cardita (Carditamera) radiata Sowerby, Hertlein and Strong, 1946, Zoologica, vol. 



31, pt. 3, No. 8, p. 108. 



Shell elongate, rectangular, widest or highest in the anterior region 

 under the beak, the anterior side shorter with rounded margin, the posterior 

 longer, its dorsal and ventral margins straight but approach each other 

 slightly, the posterior end produced and pointed. Sculpture is formed by- 

 low, rounded ribs, almost equally strong over the whole surface, their inter- 

 spaces flat and widely grooved; the ribs on the anterior slope finely noded, 

 the others usually flat except the rib along the posterior-dorsal margin which 

 may be coarsely scabrous. The posterior-umbonal slope is low, not angled 

 or vaulted. Color generally with a white base with the ribs irregularly 

 blotched with brown or black, except on the posterior slope which is uni- 

 colored. 



Length 46.2 mm., height 20 mm., diameter 12.8 mm. Rey Island, Pearl 

 Islands, Panama. 



According to Sowerby, the original specimens of this species were 

 dredged by Cumings from a sandy mud bottom in 6 to 12 fathoms of water 

 at Salango and at Panama; Salango was selected as the type locaHty for 

 the species by Hertlein and Strong. My collections from the Ecuadorian 

 coast contain no specimens of this shell, and it is possible that Sowerby's 

 shells all came from Panama where the species is relatively common. 

 Carditamera radiata is closely allied to several Miocene and Pliocene species 

 from the southeastern United States; Carditamera dejuniak Gardner, as 

 figured by Mansfield from the Miocene of Florida being scarcely distin- 

 guishable. 



Range — Panama southward to Ecuador? Panama: vicinity of Panama 

 City; Pearl Islands; Garachine; Bucaro. 



Subgenus BTSSOMERA, new subgenus 



Type species, Cardita affinis Sowerby. 



Shell elongated, the posterior side generally wider, with a high, arched 

 or vaulted umbonal angle extending from the beak to the posterior ventral 

 margin, the posterior set of ribs strongly developed, the more anterior one 

 often flattened to nearly obsolete, the anterior-ventral side depressed. 

 Hinge weak, the lateral teeth much reduced in size and more or less 

 vestigial. Lunule small or absent. 



Carditamera (Byssomera) affinis (Sowerby) Plate 26, figures 3-3d 



Cardita affinis Sowerby, 1833, Proc. Zool. Soc. London (for 1832), p. 195 Bay of 

 Montejo and Gulf of Nocoiya.— Reeve, 1813, Conch. Icon., vol. 1, Cardita^ pi. 1, 

 fig. 6. 



