REPORT ON THE AMPHIPODA. 409 



Amphipoda, p. 162, are included "a pair of mandibles with two palps," although on the 

 same page, in the first family, the Orchestidas, the mandibles are rightly said to be without 

 palps. In the second family, the Gammaridse, the mandibles are said to be provided with 

 palps ; but that is not the case with two of the genera here mentioned, Proholiwin and 

 Dexamine. The only other family assigned to the Amphipoda is the Corophidaj. No new 

 species are described or mentioned. Proholium polyprion, A. Costa, is given without 

 explanation as a synonym of the later Pruholium megacheles, Heller. Elasinopus rapax, 

 A. Costa, is given as a synonym of Podocerus largimarms, Heller, although Heller himself 

 points out that the last uropods and telson of Elasmopus rapax do not admit of its inclusion 

 in the genus Podocerus, where nevertheless J. V. Cams has since placed it under the name 

 Podocerus rapax. 

 In the Lajmodipoda, according to the definition here given, " the mouth is furnished with a 

 circular labrum, with two maxillEe strongly dentate and without palps, and with a pair of 

 maxillipeds provided with palpiform branches." It is possible that by tlie " due mascelle 

 fortemente dentate e prive di palpi," not maxillai, but mandibles are intended, but 

 " mandibole " is elsewhere used for mandibles, which in many of the Caprellidte are 

 furnished with palps, though not in the genus CapreUa, which alone claims Stalio's notice. 

 In the Caprellidfe he says "I'apparato orale ha la medesima conformazione dei Gammaridi 

 saltatori," probably by this phraseology intending to intimate that in Caprella as in 

 OrcheMa, the mandibles are palpless. 



1877. Streets, Thomas H. 



Contributions to the Natural History of the Hawaiian and Fanning Islands and 



Lower California, made in connection with the United States North Pacific 



Surveying Expedition, 1873-75. Bulletin of the United States National Museum. 



No. 7. Washington, 1877. Amphipoda, pp. 124-138. 



The lower antennae and " posterior stylets " which were missing in Dana's specimen of Chjdonia 

 lorujipes arc here described. Lestrigonus rubescens, Dana, is reported. Hijperia tricuspidata, 

 n. s., is described, in which the first gnathopods have " the meros produced antero-inferiorly," 

 " carpus broad, produced inferiorly, but not anteriorly," while " the second pair has none of 

 the joints produced." " When the animal is at rest, the inferior antennae are evidently 

 folded up, .... in the concavity in the front of the head." At the end of the description 

 the opinion is urged that the genus Lestrigonus should be retained, instead of being regarded 

 merely as the male sex of Hyperia, but the argument seems to rest entirely on the account 

 given of the inferior antennae in the male of the so-called Hijperia tricuspidata, which, 

 however, with its folded antennae, cannot be a Hyperia, but must belong to the Platyscelida:. 

 Phronima pacifica, n. s., is described from the " North Pacific Ocean. Latitudes 4° and 

 21° north; longitudes 127° and 151° west." "This species is distinguished from P. 

 sedentaria by the broadly-quadrate form of the carpus of the third pair of thoracic feet, 

 and by having the carpus of the gnathopoda less produced anteriorly. In other respects 

 they are similar. The shape of the hand more nearly resembles the hands of P. custos and 

 P. horneensis ; but it is distinguished from both of the latter, by the character of the anterior 

 surface of the carpus and of the propodus. In the latter both the carpus and propodus 

 are furnished with a crenulated tubercle ; in custos the tubercle is single and tooth-like. 

 There is a striking resemblance between the propodus, and the anterior surface of the carpus 

 of the third pair of thoracic feet, of the smaller specimens of ^jac(/?ca, and the corre- 

 sponding parts of P. atlantica, which is said to be the female of sedentaria ; the broad hand, 

 however, separates them. It is a remarkable fact, that in all the species of Phronima 



