THE MYSIDACEA 



175 



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

 propodite (except in most Petalophthalmidae and some species of 

 ^iri'll(i) divided into secondary segments 

 from two (Boreomysis, Siriella) to eight or 

 nine in number. The dactylopodite is 

 usually small, and terminates in a claw-like 

 spine. In Hetcromysis the third pair are 

 enlarged and prehensile. 



In all Mysidacea the first pair of thoracic 

 limbs have a simple lamellar epipodlte (Fig. 



105, A, ep} directed backwards beneath 

 the carapace. In the Lophogastridae and 

 Eucopiidae a series of ramified gills (Fig. 



106, br) 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 . 

 interest in connection with the position of 



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



Fio. 104. 



Maxillula of Gnatho})hausia 

 p, palp. (After 



A. 



d. 



ex. 



Fio. 105. 



A, first thoracic appendage (maxilliped) of Mysis. B, third thoracic appendage of same 

 The minute coxopodite is omitted in each case. 6.s, basipodite ; <l, dactylopodite ; ep, epipodite 

 ex, exopodite ; I, masticatory lobes or endites of basipodite, ischiopodite, and meropodite ; prp 

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



