214 



XV!. Description of a New Species of Argulus 



BY D. S. KELLICOTT. 



I FOUifD, parasitic on Lcindosteus osseus, taken in the Niagara 

 Eiver, at Buffalo, in September, 1876, an Argulus which seems to 

 be uudescribed. I present the following description and figures and 

 propose the name : 



Argnlus Lepidostei. 



Carapace obcordate, greatest breadth a little more than one-half the entire 

 length of body ; convex, transparent, its lobes barely covering the third pair 

 of swimming legs. Eyes brown, compound, having about sixty areolae. An- 

 tennae, first pair two-jointed, second joint terminating in a slender hook, basal 

 joint nearly as broad as long, having a hook on its anterior margin, also an- 

 other on its posterior (difficult to show in figure) ; second pair slender, one- 

 third longer than the first pair, five-jointed, first joint bears a hook at its base, 

 second nearly at right angles to the first (articulation with the same obscure), 

 third as long as the first two, also equal in length to the fourth and fifth to- 

 gether, the last articulation being very slender. There are spines at the artic- 

 ulations. Posterior to the antennae on either side of the extremity of the 

 siphon in line with the eyes are two stout brown hooks. Abdomen one-third 

 as long as cephalothorax, as broad as long, deeply notched, lobes acute ; on the 

 inner margin near the apex is a slender tubercle with a few hairs ; bodies at 

 the base of the lobes (female) large, brown, ellipsoidal. Legs, first pair termi. 

 nated by suctorial discs, second or ambulatory pair with three strong teeth on 

 the thighs, the outer two rising from the same base, the inner one removed 

 from the outer two one-half its length, more slender, the last joint ends in 

 two hooks; just back of the insertion of the second pair are two pairs of 

 hooks directed backwards ; the remaining four pairs, the nalatory legs end 

 each in two long pinulae, the third and fourth pairs having an extra recurved 

 pinula; while the third, fourth and fifth pairs are three- jointed, the sixth is 

 obscurely two-jointed, with an appendage at base, these appendicular lobes 

 slightly curved backwards, obtuse, reaching to the margin of the abdomen, 

 covered with hairs. 



Color light yellowish green, upper part of body blotched and streaked with 

 violet brown. Length of female .38 of an inch, greatest width of carapace 

 1.9 of an inch. 



