NO. 2063. NORTH AMERICAN PARASITIC COPEPODS— WILSON. 625 



Color (preserved material), a uniform grayish- white. 



Specific characters of male. — A single male was foimd by Kellicott 

 "attached to the extremity of the female's abdomen, and so firmly 

 that he coidd not be removed without mutilation." Consequently, 

 no description was given of its general appearance or appendages, 

 and as no other specimen has ever been obtained, it may be said that 

 the male is unknown at the present time 



ifioregoni, the generic name of its chief host.) 



i?gmarZ:s.— This is undoubtedly a valid species, but there has been 

 in the past some trouble in deciding whether the forms described by 

 Smith and Kellicott were identical, and recently whether the Ach- 

 iheres coregoni ^ of Baumann was really a new species or the same 

 as that of Smith and Kellicott. Smith figures and describes the 

 mandibles and maxillipeds, while Kellicott considered only the re- 

 maining appendages. Fortunately Smith's cotypes are available 

 and we fiiid that they correspond as fully with the figures and de- 

 scription given by Kellicott as they do with those published by 

 Smith himself, and there can be no further doubt of the idenlity of 

 these two forms. We find also that Baumann's species corresponds 

 in all essential particulars and differs only in minor details. In fact 

 there is no greater difference than would naturally be expected in 

 specimens from such widely separated localities. However, the 

 present author sent one of Smith's specimens to Doctor Baumami 

 for comparison, and he says of it: 



Die fragliche Achtheres-Art hat nun allerdings den gieichen Aufenlhaltsort und eine 

 entfernte Aehnlichkeit mit der von mir beschriebenen, Zeigt aber im Ban der Mund- 

 gliedmassen Abweichungen auf die einzutreten mich zu weit fuhrtsn wurde, die es 

 mir aber im moglich machen, die beiden Arten zu vereinigen (p. 178). 



If the two species are the same the identity of the names does no 

 harm, but if they are distinct Smith's name will take precedence and 

 Baumann must give his species a new name. 



The species may be readily recognized by the contour of the doi-sal 

 surface of the head, by the enonnous maxillipeds, each of which is 

 nearly as large as the head, and by the narrow waist behmd the base 

 of the second maxillae. The ridges on either side of the external 

 openings of the oviducts are also peculiar, as may be seen in figure 80, 

 and they show up prominently in preserved specimens. 



Relative to the transference of this species to the present genus, 

 we may quote Smith's remark at the close of his description: "This 

 species is probably not a true Lernaeopoda, and is perhaps the repre- 

 sentative of an undescribed genus" (p. 665). 



1 Revile Suisse de Zoologie, vol. 21, No. 5, pp. 100-171, pi. 5, figs. S-12. 

 34843°— Proc.N.M.vol.47— 14 40 



