278 ZOOLOGY. 
In Lerneonema radiata Steenstrup and Littken (Fig. 234), 
we find the lowest term in the series of, degradational forms 
of this order. The 
c , mouth-parts are here 
| converted into five 
[7 ) iT roots, radiating from 
mL the head ; the body 
] $A is not segmented, and 
1s : ] 
Pi ends in two long egg- 
ve. ne and testis: () of a eopenod masses. 
euroma), side view. @, ces ‘us ; V, Stomach 3 1 
¢ blind sac Yeading from the. atoraath 4, intes- In Penella (Fig. 
rina a oes i a, coiled vas deferens.—After Claus, 236) the body is cord- 
, like, buried in the 
flesh of the sun-fish or sword-fish, etc., the females having 
two long, string-like 
egg-sacs. The speci- ye 
men figured was taken 
from a sword-fish off (") 
Portland, Maine. 
In Lernea branchia- faa 
dis Linn. of the gills of 
the cod, the body is 
thicker, the root-like 
i 
appendages grow deep a 
into the flesh of its 
host, like twisted and eae J 
gnarled roots, while the ae 
shapeless sac-like body 
is filled with eggs. 
In Actheres, we as- 
cend a step higher in 
the perfection of or- 
gans; the creature is 
giteoled by ‘ Lone oF Fig. 238,—Canthocamptus caver- Fig, 234— 
jaws which unite to narum of Mammoth Cave, much Fish-louse of 
form a sucker, the an- "8° oi eplreey 
tenne are present, though rudimentary, while ~AfeVel 
the abdomen is faintly segmented. A. Carpenteri Packard 
(Fig. 235) lives on the trout in Colorado. 
