106 AXEL A. QLSSON 



This is a species of the Peruvian faunal province not ranging north of 

 Paita. It is often a common fossil in the Peruvian tablazos. Beach speci- 

 mens are usually worn smooth. The typical form of ovata is rounded sub- 

 ovate, the more elongate elliptical form is that named intermedia and if 

 fairly constant may perhaps be separated as a subspecies. 



Range — Paita southward to Chile. Peru: Paita Peninsula; Bay of 

 Sechura; Lobos Islands; Callao, 



Glycymeris (Glycymeris) macniata (Broderip) Plate 11, figures 2, 5 



Pectunculus maculata Broderip, 1832, Proc. Zool. Soc, p. 126.— Reeve, 1843, Conch. 



Icon., vol. 1, Pectunculus, pi. 1, fig. 4. 

 Glycymeris (Glycymeris) maculata (Broderip), Hertlein and Strong, 1943, Zoologica, 



vol. 28, pt. 2, p. 150. 



The shell is often large (length 80 mm.), convex, heavy, nearly cir- 

 cular, the posterior side with a low, obscure angulation. Surface smoothish 

 but when fresh showing a submicroscopic sculpture of low, rounded riblets 

 on the umbones crossed by small, equidistant concentrics becoming grad- 

 ually replaced ventrally by fine, raised radial threadlets which are evenly 

 distributed and not bunched together in riblike groups. Hinge plate solid, 

 the teeth relatively few, the laterals large, the middle series continuous or 

 broken. Ground color white, thinly or thickly speckled with brown streaks, 

 more or less arranged in a zigzagged pattern. Interior of shell white, the 

 umbonal cavity and the beaks tinged with violet or brown. 



Length 69.5 mm.; height 70.2 mm.; diameter 46.4 mm. 



Punta Blanca, Ecuador. 



Range — Lower California to northern Peru. Panama: Pearl Islands; 

 Guanico. Ecuador: Sua; Isla la Plata; Manta. Peru: Zorritos. 



Glycymeris (Glycymeris) gigrantea (Reeve) Plate 11, figure 1 



Pectunculus giganteus Reeve, 1843, Conch. Icon., vol. 1, Pectunculus, pi. 1, figs. 3a, 



3b Guaynaas. 

 Glycymeris (Glycymeris) gigantea (Reeve), Hertlein and Strong, 1943, Zoologica, vol. 



28, pt. 3, p. 150. 

 Glycymeris gigantea (Reeve), Durham, 1950, Mem. Geol. Soc. America, No. 43, p. 56, 



pi. 2, figs. 1, 8. 



Similar to G. maculata but larger (max. about 1(K) mm.), and more 

 distinctly marked with waved or zigzagged brown bands. Periostracum 

 coarse and dark-brown in color. 



This large glycymerid seems to be restricted in its distribution to the 

 Gulf of Cahfornia. It differs principally from G. maculata by its larger size 

 and color markings, the brown spots arranging themselves in a more definite 

 zigzag pattern, and perhaps it should be accorded only a subspecific standing. 



Range — Gulf of California. Mexico. Guaymas. 



Glycymeris (Glycjinerls) lintea, new species Plate 11, figures 4, 4a 



Shell of medium size (length to about 60 mm.), broadly subelliptical, 

 longer than high, the posterior side is longer, somewhat produced and 

 pointed at the end. The sculpture is fine, formed over the middle of the 

 valve by numerous, low, rounded riblets, the whole closely overrun by 

 fine, threadlike longitudinals producing a subsidiary sculpture like that 

 of fine linen; this fine sculpture covers the whole surface evenly but the 



