116 U.S. NATIONAL MUSEUM BULLETIN 295 



Type-specimens. — Holotype male USNM 121638; allotype female 

 USNM 121639; paratypes USNM 121640. 



Type-locality. — Anton Bruun cruise 7 station 381B. 



Diagnosis. — Carapace reniform in lateral view with straight 

 dorsal margin, broadly rounded anterior and narrowly rounded posterior 

 margins, ventral margin deeply indented; females much larger than 

 males. Fused marginal zone very broad mth abundant straight 

 radial pore canals, extending to anterodorsal and posterodorsal areas; 

 inner lamella black; copulatory organ with 5 digitiform projections 

 besides short curved copulatory tube. 



Dimensions.— Adult male USNM 121638, left valve, length 0.56 

 mm, height 0.30 mm; right valve, length 0.57 mm, height 0.28 mm. 



Adult female USNM 121639, left valve, length 0.61 mm, height 

 0.34 mm; right valve, length 0.61 mm, height 0.33 mm. 



Affinities. — The carapace features represent extreme develop- 

 ment of trends seen in A. jumata; the soft-part anatomy is compatible 

 with that of A. species 1. 



Anchistrocheles antemacella, new species 



Figure 60i-l 

 Argilloecia cylindrica Sars of Colalongo, 1965, p. 88, pi. 10: fig. 6. 



Etymology. — Latin ante, before + macellus, thin. 



Type-specimens.— Holotype USNM 121641; paratype USNM 

 121642-121643. 



Type-locality. — Anton Bruun cruise 7 station 369A. 



Diagnosis.— Carapace thin, moderately inflated, nearly equi- 

 valved; anteromarginal zone very strongly compressed; lateral 

 outline approaching rectangular mth horizontal dorsal margin, very 

 slightly indented ventral margin, nearly vertical anterior margin, 

 and broadly rounded posterior margin; marginal zone moderately 

 wide and crossed by numerous straight radial pore canals. 



Material. — Subfossil specimens, 62 from Anton Bruun stations 

 361 A, G, 363E,J, 366A,C, 369A,D, and 407 in the Mozambique 

 Channel. 



Dimensions.— Adult USNM 121641, left valve, length 1.17 mm, 

 height 0.62 mm; right valve, length 1.15 mm, height 0.58 mm. 



Juvenile USNM 121642, left valve, length 0.98 mm, height 0.51 mm; 

 right valve, length 0.98 mm, height 0.48 mm. 



Affinities. — While the rectilinear outline and abundant short, 

 straight radial pore canals give this species some resemblance to 

 Zabythocypris, the equal size and moderate inflation of the valves 

 suggest that it might better be placed in the more flexibly defined 

 category Anchistrocheles. 



