160 A LIST OF THE PARASITIC COPEPODA 



LERN^ODEA. 



Penella, Ohen. 



Thoracic legs close together, found just behind the head, neck without 

 distinct segments, egg sacs thread-like, the hinder part of the body (the 

 genital segment) joined to the neck in a straight line ; from the end of 

 the latter projects the abdomen, as a long plumose rod. Head rounded 

 and corrugated, carrying behind it two arm-like projections. 



Penella sagitta ? Linn. One specimen was obtained from the Labora- 

 tory, but from what fish was not known. 



LERNiEONEMA, 3filne Edivards. 



Genital segment passing gradually into the neck ; head obliquely cut 

 off, or rounded in front ; genital opening placed far off from it ; thoracic 

 legs with developed oar-like joints. 



1. Lernceoneina monillaris, Milne Edwards. A very perfect specimen 

 of this species was found attached to the sclerotic of a young herring 

 taken in November. There was no malformation of the eyeball. 



2. Lernxonenia encrasicola ? Van Beneden. A broken specimen, 

 probably belonging to this species, was taken from a Clupea alosa. 



Lernea, Linn. 



Genital segment dilated, bent in the form of an S, and twisted on its 

 axis; head in front bearing slender forked processes; neck short, simple; 

 all four pairs of thoracic legs unfolded. 



1. Lernea hrancliialis, Linnaeus. Specimens were taken from the gills 

 of the cod, bass, whiting, haddock. 



The body is always full of sanguineous fluid, and the head with its 

 long horns, together with the neck, are deeply buried in the tissues of 

 the gills and head, being surrounded by a laminated clot of blood 

 encysting those parts completely. When once fixed there is apparently 

 no power of movement. The gill cavity of a whiting would appear to 

 be almost filled up with one of these large parasites, and they must 

 materially interfere with the action of the gills. 



2. Lernea lusci, n. sp.* This animal was found only in the gills of 

 whiting-pout, Gadus luscus, and was very common, as many as four 

 being found on one fish. The whole head is surrounded by a clot of 

 blood, the elongated horn being buried by the side of the gill bone. 



* See former note, p. 156. 



