xxxviii. COI^CHYLIA—DITIIYRA. 



1. Glycymeris, incequilateralis, maculis longitudinalibus. 



inequilateral, with the colored marks disposed 

 longitudinally. 



2. pilosus, {squilateralis maculis loiigitudinalibus . 



equilateral, with the colored marks disposed 

 longitudinally. 



3. undatus, maculis tra?isversis undatis. 



with the colored marks transverse and undulate. 



4. decussatus, decussatim striata, maculis nehulosis. 



with decussate striae and clouded marks. 



5. nummarius, umbouibus tumidis, maculis sanguiiieis punctatus. 



the beaks tumid, covered with scarlet dots. 



40. NUCULA. 



* margine interno crennlato. 

 the inner margin toothed. 



1. Nucleus, obliquh ovata nitida. 



obliquely oval and glossy. 



** margine interno integerrimo. 

 the inner margin very entire. 



2. tenuis, oblique corduta Iceviuscula. 



obliquely heart-shaped and nearly smooth. 



3 rostrata, ovata, antich rostrata arctiata rotundula. 



oval, with the anterior side produced curved and 

 rounded. 



4. minuta, ovata, anticc rostrata arcuata truncula. 



oval, with the anterior side produced curved and 

 truncate. 



