MYSIDACEA 



I 19 



(Fig. 79) described by Sars, 1 may be chosen as an example of 

 the Mysidacea. 



Tlie peculiarity of this form consists chiefly in the immense 

 elongation of the endopodites of the fifth, sixth, and seventh thoracic 

 appendages. Characteristic of the Mysidacea is the freedom of 

 the hinder thoracic segments from fusion with the carapace, other- 

 wise this animal is seen closely to resemble the Euphausia figured 

 (Fig. 102). Eucopia australis, like so many of the Mysidacea, is a 



Ab.l 



A. 



FIG. 79. Kiii'njiifi iin.ffi-iifiK, young female, x 3. .), 1st antenna ; Ab.l, 1st 

 abdominal segment ; Alt. 6, 6tli abdominal appendage; /'.', eye ; T, telson ; '/'//, ".Hi 

 thoracic appendage. (After Sars.) 



deep-sea animal, being brought up with the dredge from over 1000 

 fathoms; it is very widely distributed over the Atlantic Ocean. 



Fam. 2. Lophogastridae. - -The memliers of this family 

 (Lophogaster, Gnathophau&ia) ai^rcc with the Eucopiidae in tlie 

 possession of branched gills on some of the thoracic limbs, in the 

 absence of auditory sacs on the sixth pair ol' pleopods, in tin- 

 presence of normally developed pleopods in both the male and 

 female, and in tlie brood-lamellae be in if developed on all se\en 

 of the thoracic limbs. The endopodites of the posterior thoracic, 

 limbs are, however, of a normal si/.e. 



Fam. 3. Mysidae. These differ from both the foregoing 

 families in the absence of gills, in the presence of an amlilor\ 

 sac on the sixth pleopods, in the reduction of the other pleopods 

 in the female, and in the brood-lame]l;ie licin- <le\rlopi'd only on 

 the more posterior pairs of thoracic limbs. A number of closely 



- ];, '/I, .//.,- \nl. xiii.. ixs;,. p. ;,.. 



