PANAMIC-PACIFIC PELECYPODA 465 



near the middle or slightly anterior. Surface smooth or with strong, con- 

 centric or radial sculpture, sometimes granulose and covered by a thin, 

 light brown periostracum. Ligament internal, situated in a groove or fossette 

 which sometimes projects from the hinge line; a lithodesma present. Hinge 

 teeth absent or present. An internal, posterior rib or buttress is sometimes 

 present. Interior white but not pearly. Pallia! sinus absent. 



Genus CUSPIDAEIA Nardo, 1840 

 Type species by original designation, Cuspidaria typus Nardo ( = 

 Tellina cuspidata Olivi). 



Shell small or of medium size, with a well-rounded, convex, anterior 

 side and a narrowly produced posterior end. Hinge without cardinal teeth, 

 the right valve having a strong, posterior, lateral tooth bordered above by a 

 linear socket into which the margin of the left valve fits. Chondrophore is 

 a narrow, spoon-shaped plate placed directly under the beak, directed 

 slightly backward, and similar in both valves. Surface with concentric 

 ribbing. 



Subgenus CABDI03ITA A. Adams, 1864 

 Type species by monotypy, Neaera gouldiana Hinds. 

 Shell with strong, radial ribs, and large vertically directed chondrophore. 



Cnspidaria (Cardlomya) ecuadoriana, new species Plate 83, figure 3 



The shell is small, plump and relatively thin, with a short, narrower 

 and rostrated, posterior end. Anterior and middle surface of the disk is 

 strongly inflated, its anterior-dorsal margin somewhat expanded and flaring. 

 The sculpture is produced by two, primary, radial costae which are widely 

 spaced, and which begin along the posterior side of the umbone and extend 

 across to the ventral margin which is deeply fluted by them; in front of 

 the two, primary costae, there are 20 or more, smaller radial riblets which 

 are most pronounced along the ventral side, fade away over the middle 

 towards the umbonal surface which is largely smooth. The anterior-dorsal 

 slope is strongly contracted, flaring slightly at the margin. 



Length 8.5 mm., height 5.5 mm., semidiameter 2.3 mm. a left valve. 

 Galeras, Ecuador. Holotype, ANSP 218954. 



In its sculpture, this shell is similar to some forms of C ornatior Pilsbry 

 and Johnson^^ from the Miocene of Santo Domingo, but it differs from them 

 by its more widely expanded, anterior-dorsal margin. 



Range — Ecuador. Ecuador: Galeras. 



Cuspidaria (Cardiomya) costata (Sowerby) Plate 83, figures 6, 6a 



Anatina costata Sowerby, 1834, Zool. Soc. London, p. 87 Santa Elena. 



Cuspidaria {Cardiomya) dulcis Pilsbry and Lowe, 1932, Proc. Acad. Nat. Sci. Phil- 

 adelphia, vol. 84, p. 104, pi. 17, figs. 20-22. 



Cuspidaria {Cardiomya) dulcis Pilsbry and Lowe, Hertlein and Strong, 1946, Zoologica, 

 vol. 31, pt. 3, No. 8, pp. 100, 101. 



Shell small, white under a thin buff periostracum, plump, the left 

 valve slightly larger, the beaks placed a little in front of the middle. The 



i^Pilsbry, 1922, Proc. Acad. Nat. Sci. Philadelphia, vol. 73, p. 414, pi. 28, especially 

 fig. 12. 



