NEW MALLOPHAGA. 1 33 



tion of the species, without attempting, as yet, to indicate 

 varieties by name. 



I attribute to this species specimens taken from a 

 Bufflehead, Charitonetta albeola, Mallard, Anasbosca, and 

 a Ruddy Duck, Erismatura rubtda, all from Lawrence, 

 Kansas. These specimens vary somewhat among each 

 other, and all from the descriptions of Giebel and Piaget, 

 which descriptions in turn do not agree with each other. 

 The markings of the abdomen seem to be extremely vari- 

 able, ranging from an indistinct lateral brownish coloration 

 to distinct quadrangular, sharply -emarginated lateral 

 blotches. More striking is the variation in number of the 

 long hairs in the posterior angles of the metathorax. 

 Piaget mentions two short ones, Giebel four, while all of 

 my specimens show seven, varying in length and arranged 

 as shown in figure 7, plate x. The specimen which I 

 figure was taken from a Bufflehead, Charitonetta albeola, 

 and will serve as a fairly representative illustration of the 

 species for purposes of comparison. The measurements 

 of this specimen are: body, length ^.^ mm., width .62 

 mm.; head, length .63 mm., width .44 mm. 



Oncophorus advena n. sp. (Plate xi, figs. 1 and 2.) 



A male and one female taken from the American Coot, 

 Fulica americana (Bay of Monterey, California), and a 

 male taken from a Pacific Loon, Urinator facificus (Bay 

 of Monterey, California). Can this last individual be a 

 straggler? The female resembles the female of Oncoph- 

 orus minutus Piaget, and was by me thought to belong to 

 this species until I had found the male, whose appendaged 

 antennae make it impossible to refer the American spec- 

 imens to this species. The female also on closer exam- 

 ination differs from the female minutus in its distinctly 

 broader abdomen, by possessing four hairs on posterior 



