MARINE GAMMARIDEAN AMPHIPODA 389 



1. Uropod 3 with 2-articulate ramus Heterocressa 



Uropod 3 with 1-articulate ramus Pagetina 



Genera of Pagetinidae 



Heterocressa NichoUs 



Heterocressa NichoUs, 1938. 



Type-species: H. monodi NichoUs, 1938 (original designation). 

 Species: 1, Macquarie Island, littoral. 



Pagetina K. H. Barnard 



Pagetina K. H. Barnard, 1931; 1932. 



Type-species: P. genarum K. H. Barnard, 1931 (original designa- 

 tion); 1932. 

 Species: 1, S. Georgia Island, littoral. 



Paramphithoidae 



[including Amathillopsidae Pirlot, 1934] 

 Figures 140-142, frontispiece 



Diagnosis. — One or more of coxae 1-4 (usually all) acutely pointed 

 midventrally, occasionally bifid, accessory flagellum vestigial or 

 absent, at most composed of two articles. See Acanthonotozomatidae, 

 Lepechinellidae, Pleustidae, Calliopiidae (especially Oradarea), Eu- 

 siridae, Haustoriidae, Astyridae. 



Description. — Rostrum usually well developed; body often pro- 

 cessiferous; accessory flagellum vestigial or absent; coxae large, 1-4 

 usually acuminate, or coxae slightly excavate ventrally to form weak 

 anterior-posterior points (weak bifidation) ; mouthparts variable, 

 mandible always with molar (except Bathypanoploea) and 3-articulate 

 palp, molar varying in extent and degree of trituration surface; lower 

 lip with or without inner lobes; plates of maxillipeds well developed 

 but palp varying from three to four articles; gnathopods feeble, either 

 subchelate or simple; uropod 3 with elongate lanceolate rami; telson 

 entire or partially cleft, slightly elongate or not. 



Relationship. — Most Acanthonotozomatidae, also with pointed 

 coxae, differ from Paramphithoidae by the lack of a distinct mandi- 

 bular molar and the conically grouped mouthparts. The genus Bathy- 

 panoploea {Acanthonotozoma australis Chilton, 1912) in the Acan- 

 thonotozomatidae does not have conically grouped mouthparts and so 



