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U.S. NATIONAL MUSEUM BULLETIN 271 



Figure 2A. — BASIC GAMMARIDEAN. part II: a, head, lateral aspect [mouthparts ar- 

 ranged in quadrate bundle]; h, urosome, left lateral aspect, with uropods 1-3 and telson 

 [all segments free, none extremely elongate, no uropods extremely disproportionate, all 

 uropods biramous, telson freely articulate and not thickened dorsoventrally]; c, uropod 

 3 [well developed but of medium length, rami subequal to each other, no parts greatly 

 elongate]; d, telson [of medium length, cleft about three fourths of its length]; e, gnathopod 

 2 [subchelate, equal to or larger than gnathopod 1]. 



Symbols: 1, 2, 3, etc.=articles of appendage; c = coxa; l = lacinia mobilis; i=:incisor; 



ip= inner plate; ir = inner ramus; op = outer plate; or=^outer ramus; p=palp. 



