REVISION OF RECENT BAIRDIIDAE 



109 



Figure 59. — Zabythocypris anripita, n. sp. : A,B, Asymmetrical dimorph, USNM \l\6Tl; 

 C, symmetrical dimorph, USNM 121621; D, symmetrical dimorph, USNM 121620. 

 All exterior carapace views. All X 29. 



USNM 121622, asymmetrical dimorph from Anton Bruun 363G, 

 right valve, length 1.51 mm, height 0.89 mm; left valve, length 1.58 

 mm, height 1.02 mm. 



Affinities. — Despite the extreme differences in lateral outline and 

 compression of left valve dorsal margin, the consistency with which 

 these two morphologic forms occur together in the same samples 

 suggests a Hnkage between them best explained as sexual dimorphism. 



The symmetrical, nearly rectangular, dimorph is very similar in 

 structure to Z. exaltata (Brady), which also has a fused dorsal zone 

 in the left valve. However, the lateral outline of the latter is more 

 nearly circular; it is also more robust. 



Zabythocypris helicina, new species 



Figures .54, 55 



Etymology. — Latin, Greek, helix, spiral, coil. 



Type-specimens. — Holotype female USNM 121625; paratypes 

 USNM 121626-121629. 



Type-locality. — Anton Bruun cruise 11 station 179. 



Material. — Eleven adult females and juveniles living at Anton 

 Bruun cruise 11 stations 113 and 179 in the southeast Pacific. 



Four subfossil specimens at Albatross station 2385 in the GuK of 

 Mexico. 



