CRUSTACEANS OF THE CAVE. 19 



caves, and one may yet be found ; but how- the present form be- 

 came a cave dweller is difficult of explanation, as its nearest allies 

 are certain species of Idotea which are all marine, with the excep- 

 tion of two species : I. entomon, living in the sea and also in the 

 depths of the Swedish lakes, as discovered by Loven, the distin- 

 guished Swedish naturalist, while a species representing this has 

 been detected by Dr. Stimpson at the bottom of Lake Michigan. 

 Our cave dweller is nearly allied to Idotea, but differs in being 

 blind, and in other particulars, and may be called Ccecidotea sty- 

 giob.* (Fig. 132 side view, enlarged ; Fig. 133 dorsal view ; 6, in- 

 ner antenna ; c, 1st leg.) It was found creeping over the fine 

 sandy bottom, in company with the Campodea, in a shallow pool 

 of water four or five miles from the mouth of the cave. 



This closes our list of known articulates from this and other 

 caves in this country, the result of slight explorations by a few in- 

 dividuals. The number will be doubtless increased by future re- 

 search. It is to be hoped that our western naturalists will thor- 

 oughly explore all the sinks and holes in the cave country of the 

 western and middle states. The subject is one of the highest in- 

 terest in a zoological point of view, and from the light it throws on 

 the doctrine of evolution. Professor Schiodte, the eminent Danish 

 zoologist, has given us the most extended account of the cave 

 fauna of Europe, which has been translated from the Danish into 

 the Transactions of tke Entomological Society of London (new 

 series vol. 1, 1851). 



He examined four caves ; namely, that of Adelsberg, the Mag- 

 dalena and Luege caves, all in the neighborhood of Adelsberg, 



* Generic characters. Head large, much thicker than the body, and as long as broad; 

 subcylindrical, rounded in front. No eyes. First antennae slender, 8-jointed (2d anten- 

 noe broken off). Abdominal segments consolidated into one piece. Differs chiefly from 

 Idotea, to which it is otherwise closely allied, by the 8-jointed (instead of 4-jointed) 1st 

 (inner) antenna?, the very large head, and by the absence of any traces of the three ba- 

 sal segments of the abdomen usually present in Idotea. 



Specific chai-acters. Body smooth, pure white : tegument thin, the viscera appearing 

 through. Head as wide as succeeding segment, and a little more than twice as long. 

 Inner antennne minute, slender, the four basal joints of nearly equal length, though the 

 fourth is a little smaller than the basal three, remaining four joints much smaller than 

 others, being one-half as thick and two-thirds as long as either ot the four basal joints ; 

 ends of last four joints a little swollen, giving rise to two or three hairs; terminal joint 

 ending in a more distinct knob, and bearing five hairs. Segment of thorax very dis- 

 . tinct, sutures deeply incised; edges of segments pilose; abdomen flat above, rounded 

 behind, with a very slight median projection ; the entire pair of gills do not reach to 

 the end of the abdomen, and the 'inner edges diverge posteriorly. Legs long and slen- 

 der, 1st pair shorter, but no smaller than the second. Length .25 inch. 



