THE EUPHAUSIIDiS 261 



slender as they are, would not seem, it is said, 'to be 

 specially adapted for the usual ambulatory motion, but are 

 more likely used for the purpose of seizing hold of any 

 delicate submarine objects, as Hydroids or Crinoids, fixed 

 at the sea bottom.' In preserved specimens these limbs 

 are geniculate between the third and fourtb joints. Their 

 fingers, though nearly straight, bend back against the 

 spines of the preceding joints, and may thus be very 

 efficiently prehensile. Dana's specimen was obtained 

 from the stomach of a penguin in the Antarctic ocean, a 

 habit^at which gave little reason to suspect the actual dis- 

 tribution of the species. According to the Challenger re- 

 searches it ranges from Japan to the Southern Ocean 

 and from the Southern Ocean to Nova Scotia, preferring 

 depths between 1,000 and 2,000 fathoms, though descend- 

 ing lower and mounting higher. It is presumed that the 

 spe.'imen snapped up by the penguin must have made au 

 excursion to near the surface. 



Family 3. — Euphausiidoi. 



The carapace is rather small, not calcareous, firmly 

 connected with the trunk dorsally, only the last segment 

 being completely defined above. The first maxillipeds are 

 pediform, elongate, with well-developed natatory exopod, 

 the epipod rudimentary or wanting. The seven following 

 pairs of appendages are generally uniform in structure, not 

 effectively ambulatory, geniculate and densely setose, with- 

 out any distinct finger, the hinder pairs more or less im- 

 perfectly developed. The branchias are podobranchia3, 

 wholly uncovered, digitiform-arborescent, the hinder pairs 

 rather complex, sending off a branch beneath the trunk. 

 The egg-pouch, when present, is under the hinder part of the 

 trunk, single or double, not formed by marsupial plates. 

 The pleopods are strongly developed in both sexes, natatory, 

 with a secondary lobe on the inner branch ; the first two 

 pairs are sexually modified in the male. The telson is very 

 slender, tapering to an acute point, and carrying two large 

 spiniform slightly divergent appendages, affixed at soma 



