30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



impressed. Brachial valve interior with long, stout, slightly curved 

 crura and moderately wide outer hinge plates. 



MEASUREMENTS IN MILLIMETERS 



Length 



Holotype 148 



Figured paratype 15-8 



Types.— Holotype, U.S.N. M. 235844a; figured paratype, U.S.N.M. 



235844b. 



Locality. — U. S. Bureau of Fisheries Station 5146 at 24 fathoms, 

 off Sulade Island, Tapul Group, southern Philippines. 



Discussion. — This pretty little species is listed by Dall (1920, 

 p. 292) as B. pompholyx but it is a proportionally much longer shell 

 and with completely different outline. Compared with the growth lines 

 of specimens of B. pompholyx corresponding in length to those of 

 B. elongata the two species prove to be quite distinct. 



Basiliola elongata is intermediate between B. beecheri and B. lucida. 

 It is larger than the latter but smaller than the former although its 

 outline is similar. The Hawaiian shell is stouter and has somewhat 

 stronger shoulders than B. elongata. The Japanese B. lucida is also 

 less elongated than the new species. 



Inside the brachial valves of these three species Basiliola elongata 

 has the longest crura whereas B. pompholyx has shorter crura rela- 

 tive to B. elongata and B. beecheri. 



It is interesting to note that the bathymetric range of most of the 

 specimens of B. pompholyx listed by Dall (1920) is deeper than 300 

 fathoms except for the new species and specimen U.S.N.M. 300863 

 which appears to be referable to B. elongata. 



The specimen mentioned by Jackson and Stiasny (1937, p. 10) as 

 very small and coming from Kei Island is suggestive of the new 

 species. This is cited by them as a juvenile. 



Genus EOHEMITHYRIS 1 Hertlein and Grant, 1944 



Plates 5, A, 8, B, 15, B, 20, A, B, 22, A 



Eohemithiris Hertlein and Grant, Publ. Univ. California at Los Angeles, Math, 

 and Phys. Sci., vol. 3, p. 55, 1944. 



Subpentagonal in outline, thick shelled, coarsely fibrous, translu- 

 cent to transparent ; subequivalved, the brachial valve having a slightly 



1 The spelling of Eohemithiris is here corrected to Eohemithyris to make it 

 coincide with the corrected spelling of Hemithyris. Inasmuch as Eohemithiris 



