298 



ZOOLOG T. 



In Lerneonema radiata Steenstrup and Liltken (Fig. 239), 

 we find the lowest term in the series of degradational forms 



of this order. The 

 mouth-parts are here 

 converted into five 

 "i ' f>^ roots, radiating from 

 the head ; the body 

 is not segmented, and 

 ends in two long egg- 

 masses. 



In Penella (Fig. 

 241) the body is cord- 

 like, buried in the 



oe 



Fig. 237. Intestine and testis (0 of a copepod 

 (Pleuroma), side view, oe, oesophagus ; v, stomach ; 

 A, blind sac leading from the stomach ; i, intes- 

 tine; c, heart ; vd, coiled vas deferens. After Clans, 

 from Gegenbaur. 



flesh of the sun-fish or sword-fish, etc., the females having 

 two long, string-like 

 egg-sacs. The speci- 

 men figured was taken 

 from a sword-fish off 

 Portland, Maine. 



In Lerncea branchia- 

 lis Linn, of the gills of 

 the cod, the body is 

 thicker, the root-like 

 appendages grow deep 

 into the flesh of its 

 host, like twisted and 

 gnarled roots, while the 

 shapeless sac-like body 

 is filled with eggs. 



In Adheres, we as- 

 cend a step higher in 

 the perfection of or- 

 gans ; the creature is 

 attached by a pair of 

 jaws which unite to 

 form a sucker, the an- 



tennse are present, though rudimentary, while ~ Aft< 

 the abdomen is faintly segmented. A. Carpenter i Packard 

 (Fig. 240) lives on the trout in Colorado, 



Fig. 238.Canthocamptm caver- Fig. 239. 

 nwrum of Mammoth Cave, much Fish -louse of 



the Menhaden, 

 twice enlarged. 



