MARINE GAMMARIDEAN AMPHIPODA 523 



simple. Used in amphipod taxonomy to denote the absence of spines or setae 

 on appendages; or the occurrence of but a single article in the ramus of a uropod; 

 or especially to the absence of a palm on a gnathopod or pereopod. Distinction 

 between subchelate and simple is often weak. 



splayed. Descriptive of the lateral spreading of coxae, especially in Phliantidae. 



subchelate. Article 6 of a gnathopod or pereopod having a distal palm against 

 which article 7 closes; a prehensile condition in which the palm is not produced 

 to form a finger; intermediate in condition between chelate and simple. Com- 

 plexly subchelate or complexly chelate are terms referring to the formation 

 of a false chela by protrusion of teeth, cusps, or lobes from articles other than 

 the sixth and upon which article 7 impinges to form a prehensile condition; 

 occurring especially in Aoridae, Corophiidae, and Leucothoidae (fig. 2e). 

 See "simple." 



telson. A flap dorsal to the anus attached to pleonite 6, primitively bilobed 

 but usually in Amphipoda with bases coalesced and often with lobes completely 

 coalesced to form a single plate (figs. 1, 2d). 



triturative. Descriptive of the rasp-like surface of a mandibular molar, composed 

 of teeth, ridges, and cusps. 



upper lip (labrum). A fleshy lobe attached to the anterior cephalic margin in 

 front of the mandibles; occasionally the anterior surface of the labrum pro- 

 trudes as a lobe or cusp; often the cephalic area to which the labrum is attached 

 is recognizable as an "epistome" and may also be lobed; or both labrum and 

 epistome may be indistinguishable and produced together as a single lobe. 



uropod. One member of the three pairs of terminal pleonal appendages, each 

 formed of a peduncle and two rami (fig. 1) (occasionally rami of uropod 3 reduced 

 or absent, rarely rami of uropods 1-2 absent or reduced). 



urosome. The complex of pleonites 4, 5, 6, carrying uropods, and telson. Often 

 numbered as urosomites 1, 2, 3 (fig. 1). 



urosomite. A segment of the urosome. 



285-135 O - 69 - 34 



