298 



ZOOLOGY. 



■Fig. 237.— Intestine and testis (t) of a copepod 

 {PUnroma), side view, oe, oesophagus ; y, stomach ; 

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

 tine; c, heart ; ^)rf, coiled vas deferens. —After Glaus, 

 from Gegenbaur. 



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 

 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 

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

 a long, string-like ap- 

 pendage. The speci- 

 men figured was taken 

 from a sword-fish ofE 

 Portland, Maine. 



In Lemma hranchia- 

 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 Actheref!, we as- 

 cend a step higher in 

 the perfection of or- 

 gans ; the creature is 

 attached by a pair of 



!,• u -4- 4. ^'g-^S.—Canfhocamritu^ caver- Fie, 239.— 



]aWS WniCn unite to narnm of Mammoth Cave, much Fish-Ionse of 



form a sucker, the an- ''"'"^'''- tw1c^ln".a"4rd: 



tennse are present, though rudimentary, while AfterVemii. 

 the abdomen is faintly segmented. A. Carpenteri Packard 

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



