PANAMIC-PACIFIC PELECYPODA 409 



This is a species of the Gulf of California; more southerly records as 

 from Panama are questionable. S. ochracea Carpenter is an allied form, said 

 to differ from S. viridotincta by its deeper orange or brown color. 



Range — Gulf of California to Panama? Panama: Panama (Jewett). 

 USNM 22823. 



Genus HEKTELLINA, new genus 



Type species Tellina {Scissula) nicoyana Hertlein and Strong. Costa 

 Rica. 



Shell subelliptical, thin, nearly equilateral {Sanguinolaria-Wke in shape), 

 the anterior side a little longer than the posterior. Surface smooth with 

 indistinct growth lines and a heavier sculpture of concentric ribbons between 

 incised lines which are a little oblique to the growth lines and margin of 

 the valve. Hinge plate narrow and delicate, the teeth small; right valve has 

 two, small, grooved cardinal teeth and a long, narrow, anterior lateral placed 

 fairly close to the cardinals and a distant posterior lateral tooth; left valve 

 has two cardinal teeth of which the anterior one is bifid, the other simple. 

 Pallial line is large and deep but not reaching to the anterior adductor scar 

 but separated from it by considerable space, the lower limb confluent with 

 the pallial line below. 



Externally shaped like Sanguinolaria, but with hinge characters of 

 Eury tellina. 



Named to honor Dr. Leo George Hertlein of the California Academy 

 of Sciences in recognition of his many major contributions to the paleon- 

 tology and malacology of the Pacific region. 



Hertelllna nicoyana (Hertlein and Strong) 



Tellina (Scissula) nicoyana Hertlein and Strong, 1949, Zooiogica, vol. 34, pt. 2, pp. 85, 

 86, pi. 1, figs. 23-26. 



The shell is relatively small, elongately ovate to elliptical, thin, mildly 

 convex, and of a pale rose or pink color. The surface is smooth, the lines 

 of growth weak but with a stronger sculpture of concentric ribbons between 

 evenly spaced incised lines which begin on the posterior-middle side of the 

 disk and run diagonally to the margin in the middle zone and concentric 

 or parallel to the margin on the anterior side. 



Length 34.4 mm., height 19 mm., diameter 7.8 mm. Ballena Bay, Gulf 

 of Nicoya, Costa Rica. Holotype, CaHf. Acad. Sci. 



This is evidently a rare species known only from a few specimens. The 

 shape is like that of a small Sanguinolaria but the hinge is that of a Tellina. 

 A specimen labelled Sanguinolaria panamensis Dall (evidently an unpub- 

 lished name) is in the collection at the U. S. National Museum from Bay of 

 Panama (USNM 96361). I have a single valve which was dredged off 

 Zorritos, Peru. 



Range — Costa Rica to northern Peru. Panama: Panama Bay (USNM). 

 Peru: Zorritos. 



Subfamily MAC03IINAE 



The valves are tellinoid in shape, the anterior side usually longer, the 

 posterior side shorter, with or without a pronounced flexure. The hinge is 

 provided with small cardinal teeth but the lateral margins are plain and 



