MARINE AMPHIPODA IN MICRONESIA — BARNARD 531 



Africa: (1) the lack of an anterodistal process on article 2 of gnatho- 

 pod 2, perhaps due to immaturity, and (2) the spinose inner edges of 

 the dactyls on both gnathopods, perhaps overlooked by Reid. The 

 male has a spiniform median keel on the sternites, commencing on 

 segment 1 and ending on segment 5, with a sHght keel on segment 6, 



as drawn. 



It is impossible to separate females of this species from females 

 of L. processifer as herein identified, and only where males of Lembos 

 species have occurred can some distinction be made between the 

 species. Essentially, the males of this species resemble large females 

 of L. processifer except for the ventral keel and lack of brood plates; 

 that these specimens are not simply aberrant intersexes of L. processifer 

 is demonstrated by the difference in ventral keels as seen in the 

 accompanying drawings. 



Distribution: Ifaluk Atoll, Caroline Islands; Eniwetok Atoll, 

 Marshall Islands. 



G^nus Microdeutopus Costa 

 Microdeutopus tridens Schellenberg 

 Figure 28/ 

 Microdeutopus tridens Schellenberg, 1938a, pp. 74-75, fig. 38. 



Material: Abbott stations 31-D-2 (2), 32-G-3 (1), 40-E-3 (1), 

 41-D-3 (2), 42-F-2 (1), 81-B-4-d (4), 112-1-5 (1), 113-H-2 (10), 

 126-C-4 (3), 132-E-4 (1), 136-C-4 (1), 137-E-6 (9), 138-E-4 (4), 

 141-D-3 (2), 146-151-H-4 (1), 155-157-G-l (2), 158-159-D-5 (7), 

 167-D-4 (3), 176-G-4 (4), 177-G-5 (8), 179-184-M-l (35), 192-D-6 

 (2); Bayer stations 592 (1), 754 (1); Reish station E-24 (1). 



Remarks: The female first gnathopod is drawn for comparison 

 with that of female Lembos processifer (figure 27 m). 



Distribution: Gilbert Islands; Ifaluk Atoll, Carohne Islands; 

 Eniwetok Atoll, Marshall Islands. 



Family Photidae 



Genus Eurystheus Bate 



Audulla Chevreux, 1901, pp. 431-432. [New synonymy.] 

 Eurystheus Bate. — Stebbing, 1906, p. 610. 



Such multispecific genera have always caused difficulty to tax- 

 onomists, especially because of apparent intraspecific polymorphism. 

 Notably this has been true of the species E. atlanticus (Stebbing 1888) 

 and E. afer (Stebbing 1888). As originally described and figured by 

 him, they seemed to be clearly distinct although, at the time, Stebbing 

 thought they might be varieties of a single species. Eurystheus afer 

 bears short lateral head lobes, scarcely distinct from the front head 



