18 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



lxii: figs. l-4j are incompletely known, but lateral outline of the 

 shell is more acuminate anteriorly than that of P. pollex. Un- 

 fortunately, specimens identified by Sharpe (USNM 13108) are 

 missing from the museum collection, so that appendages could not be 

 examined. Specimens from off the California coast identified as 

 Cylindroleberis mariae (Baird) by Juday (1907, p. 143) are described 

 incompletely, but, according to the description of the furca (Juday, 

 1907, p. 144), each lamella bears 10 claws; it thus differs from the 

 furca of P. pollex, which has only 8 to 9 claws on each lamella. 



Cyridina oblonga Grube (1859, p. 335) has only 11 bristles on the 

 7th limb and no bristles on the anterior corner of the 6th limb (Grube, 

 1859, pi. xn : fig. e). Specimens identified as Cylindroleberis oblonga 

 (Grube) by Muller (1894, p. 219) differ from P. pollex in having 25 

 posteroventral and 4 anteroventral bristles on the 6th limb (Muller, 

 1894, pi. 5: fig. 33). Specimens identified a,s Asterope oblonga (Grube) 

 by Sars (1887, p. 203) have a 6th limb with 24 posteroventral and 6 

 anteroventral bristles (Sars, 1887, pi. 5: fig. 10). Specimens identified 

 as Cylindroleberis mariae (Baird) by Brady (1868, p. 465) have 6 

 anteroventral bristles on the 6th limb (Brady, 1868, pi. 41: fig. if); 

 the 3rd joint of the 1st antenna of the adult female of Brady's speci- 

 mens has 6 dorsal bristles (pi. 41: fig. lc) compared to 5 on P. pollex. 



Specimens identified by Sars (1887, p. 203) as Asterope elliptica 

 Philippi have about 24 posteroventral and 5 to 6 anteroventral bristles 

 on the 6th limb (Sars, 1887, pi. iv: fig. 1). Asteropina extrachelata 

 Kornicker (1959, p. 241) has on the 6th limb 24 posteroventral and 4 

 anteroventral bristles. Asteropina setisparsa Kornicker (1959, p. 239) 

 has only 1 posteroventral bristle and 3 anteroventral bristles on the 

 6th limb. The carapaces of the adult male and female of Asterope 

 judayi Hartmann (1959, p. 201) are shorter than P. pollex, and the 

 height of the female shell is 62 percent of its length, according to 

 Poulsen (1965, p. 347), who estimated it from Hartmann's figure 

 (Hartmann, 1959, pi. 33: fig. 32). The height of the female shell of 

 P. pollex is only 51 to 55 percent of its length. 



The N-l instar of the male of P. pollex resembles Diasterope tenuista 

 Poulsen, 1965, of which only the juvenile male is known. It differs 

 from that species in having a thumblike posterior process and slender 

 c- and d-bristles on the 2nd endopodite joint of the mandible. 



Cushman (1906, p. 366) identified specimens collected in the "Gulf 

 of Canso" across from Woods Hole, Mass., on Aug. 3, 1905, as Cylin- 

 droleberis mariae (Baird). The USNM contains in its collection a 

 slide containing 4 dried ostracods (USMN 114061) labeled "Cylin- 

 droleberis mariae Baird, Aug. 3, '05, Gulf of Canso, Woods Hole, 

 Mass., Coll. by J. A. Cushman." One of the 4 is an adult male and 

 another an adult female with 10 ostracod eggs in its brood chamber. 



