246 AXEL A. OLSSON 



Range — Gulf of California to Ecuador and the Galapagos Islands. 

 Panama: Pearl Islands. Ecuador: Manta, Santa Elena. 



Subgenus PHLOGOCABDU Stewart. 1930 

 Type species by original designation, Cardium belcheri Broderip and 

 Sowerby. 



Shell like Trachy cardium, s.s., in shape and sculptured with strong ribs, 

 but the ribs without imbricating scales, instead they have a high, coarsely 

 toothed or frilled cord along their posterior side which may partly over- 

 hang the adjacent interspace. 



This is a well-marked group of cockles represented by several fine 

 species in the Miocene of Florida and the Caribbean region. The curiously 

 corded frill developed along the posterior side of each rib is often complex 

 and elaborate, and Dall, commenting on this feature, compared it to a 

 twisted ribbon of candy. 



Trachycardinm (PMogocardia) belcheri (Broderip and Sowerby) Plate 37, figure 2 



Cardium belcheri Broderip and Sowerby, 1829, Zool. Jour., vol. 4, p. 366, pi. 9, fig. 3 

 Gulf of California. — Sowerby, 1840, Conch. Illust, Cardium, p. 3, No. 41 

 Coast of California and Panama. — Reeve, 1844, Conch. Icon., vol. 2, Cardium, 

 pi. 1, fig. 5. 



Cardium {Phlogocardia) belcheri Broderip and Sowerby, Hertl«in and Strong, 1947, 

 Zoologica, vol. 31, pt. 4, p. 140. — Hertlein and Strong, 1955, Bull. Anner. Mus. 

 Nat. Hist., vol. 107, art. 2, p. 186. 



Shell ovate, higher than long, convex, with 24 or 25 strong, triangular 

 ribs. A large specimen recorded by Hertlein and Strong measured approxi- 

 mately 53 mm. in height. 



Length 38.1 mm., height 42.3 mm., diameter 36 mm. Panama Bay. 

 (Shrimpers). 



Apparently an offshore species and seldom found on the beach. Fossil 

 in the Pliocene of Ecuador. 



Range — Gulf of California to Ecuador Panama: Gulf of Chiriqui in 

 35-40 fathoms; Panama Bay (shrimpers). 



Subgenus DALLOCAKDIA fitewart, 1930 



Type species by original designation, Cardium quadrigenarium Conrad 

 (=C. quadragenarium Conrad). 



Like Trachycardium, s.s., but the shell usually more rounded, thinner, 

 the ribs smaller, with small scales or nodes along their edge (posterior), 

 nearly lacking from the ribs in the mid-zone and umbones. 



Trachycardium (Dallocardia) senticosnm (Sowerby) Plate 37, figure 3 



Cardium senticosum Sowerby, 1833, Proc. Zool. Soc. London, p. 84.— Sowerby, 1840, 



Conch. Illust. Cardium, p. 3, No. 43, fig. 10.— Reeve, 1844, Conch. Icon., vol. 2, 



Cardium, pi. 16, fig. 82, (in text as C. rastrum). 

 Cardium (Trachycardium) senticosum Sowerby, Maxwell Smith, 1944, Panaraic Marine 



Shells, p. 58, fig. 740. 

 Cardium (Dallocardia) senticosum Sowerby, Hertlein and Strong, 1947, 2:oologica, vol. 



31, pt. 4, pp. 147, 148. 



