THE MYSIDACEA 



175 



■without n claw. The remaining pairs (Fig. 105, B) have the 

 propodite (except in most Petaloplithalmidae and some species of 

 Sirirlla) divided into secondary segments 

 from two (liOirotnysis, Shielhi) to eight or 

 nine in number. The dactylopodite is 

 usually small, and terminates in a claw-like 

 spine. In Hdcromijsis the third pair are 

 enlarged and prehensile. 



In all Mysidacea the first pair of thoracic 

 limbs have a simple lamellar ejiipodlte (Fig. 



105, A, ep) directed backwards beneath 

 the carapace. In the Lophogastridae and 

 Eucopiidae a series of ramified gills (Fig. 



106, hr) are developed in connection with 

 the last seven thoracic limbs. Each consists 

 of three or four main branches, which are 

 again bipinnately or tripinnately divided. 

 The largest branch is bent round on the 

 sternal surface of the thorax between the 

 insertion of the limbs, a point of some sars!)^"'" 

 interest in connection with the position of 



the gills in the Amphipoda. Although the gills of the Lopho- 



Fk;. 104. 



Maxilhila of O nathophausia 

 p, palp. (After 



Fig. 105. 



A, lirst thoracic ai)pen(la','e (maxilliped) of Mysis. B, third thoracic appendage of same. 

 Tlie minute coxopoditp is omitted in each case, fe, basipodite ; (/, dactylopoclite ; ep, epipodite ; 

 ex, exopodite ; /, masticatory lobes or endites of basipodite, ischiopodite, and meropodite ; 2>rPt 

 Ijrojjodite, divided into .seven segments in B. (After Sars.) 



