NEW MALLOPHAGA. 113 



length 2.5 mm., width .62 mm.; head, length .56 mm., 

 width .4 mm. The characteristic markings of the species, 

 especially the large and sharply-defined signature, make 

 it easily recognized. 



Nirmus pileus Nitzsch. (Plate vi, fig. 6.) 



Germar's Mag. Eutomol., 1818, vol. iii, p. 291. 



Nirmua piU us Nitzsch, Zeitschr. f. ges. Naturwiss., 1866, vol. xxviii, 

 p. 373; Giebel, Iusecta Epizoa, 1S74, p. 162; Piaget, Les Pedicu- 

 lines, 1880, p. 182, pi. xv, fig. 6. 



A single specimen, female, taken from an American 

 Avocet, Recurvirostra americana (Lawrence, Kansas). 

 Nitzsch's and Piaget's specimens were taken on Recur- 

 virostra avocetta. I figure the female, although Piaget's 

 figure is excellent, for the convenience of American stu- 

 dents. The measurements of the specimen are : Body, 

 length 2.8 mm., width .78 mm.; head, length .62 mm., 

 width .60 mm. These measurements vary a little from 

 Piaget's, my specimen being shorter and wider, and the 

 head a fifth greater in length and width. 



Nirmus lineolatus Nitzsch. (Plate vi, figs. 7, 8 and 9.) 



Zeitsch. f. ges. Naturwiss., 1866, vol. xxviii, p. 376 (ed. Giebel). 

 Nirmus ornatus Grube, v. MiddeiidorfFs sibir. Eeise zool., vol. i, p. 



477, pi. i, fig. 4. 

 Nirmus lineolatus Nitzsch, Burrneister, Haudb. Entomol., 1838, vol. 



ii, p. 428; Giebel, Iusecta Epizoa, 1874, p. 177; Piaget, Les Pedi- 



culines, 1880, p. 199. 



I have taken this common Nirmus of the gulls from 

 Larus argentatus smithsonianus, brachyrhynchus, glau- 

 cescens, canus, vegce, occidentalis, heermanni, calif ornicus, 

 delezvarensis (Bay of Monterey, California). Nitzsch 

 found it on Larus canus, argentatus, g/aucus, tridactylus, 

 and Piaget on argentatus and g/aucus. It is readily distin- 

 guishable by its characteristic head markings and by the 

 ventral abdominal blotches and the genitalia of the male. 

 The young, which I have found in many stages of growth, 



Proc. Cal. Acad. Sci., 2d See., Vol. VI. (8) March 13, 1896. 



