432 



anterior margin is almost straight, with a small distal projection; the ante- 

 rior distal angle of the 3rd-4th segments and the posterior distal angle of 

 the 4th-5th segments are stretched below and highly acuminate; the 5th 

 segment is anteriorly unevenly denticulate; the 6th segment is narrow, 

 clawlike, and slightly longer than the 5th. Pereopods VII have a large, 

 greatly broadened 2nd segment, slightly shorter than the analogous seg- 

 ment of pereopods VI; the distal part of the extremity is totally reduced 

 or a short rediment of the 3rd segment is present. 



The pleon is the same length as the last four somites of the pereon 

 together. The urosomites have an indistinct dorsal keel which forms a 

 small denticle on the posterior margin of the somite. The uropods are 

 broadly rounded at the tip. 



Distribution: Tropical, subtropical, and temperate waters of all the 

 oceans. It is found from the surface down to 1,000 m, rarely deeper, 

 and often forms local concentrations in the surface zone. It does not 

 exhibit distinct diurnal migrations although migration at night of part 

 of the population to the surface layers of the water has been reported 

 (Thurston, 1976b). 



2. Genus Anchylomera Milne-Edwards, 1830 



Milne-Edwards, 1830: 394; Stebbing, 1888: 1453; BovaUius, 1889: 408; 

 Chevreux and Page, 1925: 414; Spandl, 1927: 167; Bowman and Gruner, 

 1973: 39. 



The head is roundish, its height twice its length and considerably 



more than the height of the somites of the pereon. Antennae I in females 



are three-segmented, antennae II in the form of a small tubercle directly 



351 below the base of antennae I. In males the head is relatively small, the 



antennae well developed, with a multisegmented flagellum. 



The dorsal side of the body is devoid of keels and denticles. 

 The pereon and pleon are approximately the same length and height. 

 Somites I-II of the pereon are completely fused. Pereopods I-II are 

 small, with a clinging distal part; the 6th segment is conically 

 narrowed distally while the claw may be bent at an acute angle to 

 it. Pereopods III-V have a subchela, particularly well developed in 

 pereopods V. Pereopods VI are also of the prehensile type because of the 

 movable articulation between the 6th and weakly broadened 5th segment 

 which, with some approximation, could be considered an imperfect 

 subchela. Pereopods VII are fully segmented. 



The epimeral plates have rounded margins. The urosome is shorter 

 than the pleon. The uropods have ovally broadened basipodites. The 

 telson is small and rounded. 



Type species: Anchylomera blossevillei Milne-Edwards, 1830. 



The genus is monotypic. 



