'^^^ PROCEEDINGS OF THE NA TIONAL MUSEUM. 



ARGULUS LEPIDOSTEI Kellicott. 



Plate XVI. 



ArguUs lepidostei^ Kellicott, description of a new species of Argulus, Bull. Buffalo 

 hoc. Nat. Sci., Ill, 1877. 



Carapace elliptical, longer than wide; posterior sinus less than one- 

 third the length of the carapace, wider than deep. 



Abdomen broad ovate, more than one-third the k'ngth of the rest of 

 he body, as wide as long-; anal sinus broad triangular, cut half the 

 length of the abdomen; papilhe lateral, near the tips of the acute lobes 

 feuckmg disks medium size and placed well forward; posterior maxilli- 

 peds rather small but stout and well armed on their ventral surface 

 their basal joint wider than that of the swimming legs; basal plate 

 mirrow, abruptly triangular posteriorly; teeth long, narrow, and very 

 sharp. ' •> 



First antenmv rather weak, having two slender hooks, but onlv a 

 single very small spine; second antennae larger and better armed 

 fewimming legs reaching beyond the edge of the carapace; lobes on 

 he basal pints of the posterior legs enormous, boot-shaped, reachino- 

 beyond the edge of the abdomen. 



Flagella present; a long slender papilla on either side of the openino- 

 of he oviduct In the male the abdomen is considerably lengthenecf 

 with a rounded lobe on either side at its base; in addition to the regu- 

 lar accessory copulatory organs, the basal joint of the second leo-s" is 

 prolonged backward into a wide flap, reaching beyond the third leo-s 

 T- / .'h 'l/^VT^'^ ^"^^^ ^" ^^^ anterior surface of the second 

 color ^' ''^ '^' "^'"^'"^ '"'^- ^^^' ^""'y •'^"'^^"' ^'''^™^^ in 



Color a light yellowish green, with the upper part of the body 

 blotched and streaked with violet brown. 



Length, 0.2 iirni. ; leirgth of carapace, 3.75 mm. ; breadth of carapace, 

 ->.5 mm.; length of abdomen, 1.75 mm.; breadth, 1.7 mm. Male 

 about two-thirds this size. 



This specias was found parasitic on Zep/dosteu. osseu. Unn^u. in 

 the Niagara River, at Buffalo, in September, 1S76, bv D. S. Kellicott 

 who desc^ribed and figured the fennile in the periodical above referred 

 to. He had not at that time obtained any males 



Univer^f "^.^"^T" 'l^'"^" ^^'"'^ ^''''''''^ «^ '^'^ Ohio State 

 Lniveisit>, at Columbus, where Professor Kellicott was stationed for 

 many years I have been enabled to examine personally Kellicott's 



W P f ""^«^°^„*^^"^ ^ ^^'^^^ wl^ieh is here described for the first 

 time. Professor Kellicott writes that— 



The favorite place for the parasite to fasten is immediately back of the pectoral 

 tenldV !' '"'" '''' '''' ^^^ ^"'i '-'-^ -bout the Jk, then retunfinir 



ledson to Deiieve that it may also occupy the gill cavities. 



