NEW MALLOPHAGA. II3 



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. 

 Nirmus pileus Nitzsch, Zeitschr. f. ges. Naturwiss., 1866, vol. xxviii, 

 p. 373; Giebel, Insecta Epizoa, 1874, p. 162; Piaget, Les Pedicu- 

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



A single specimen, female, taken from an American 

 Avocet, Rccurvirostra americana (Lawrence, Kansas). 

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

 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.) 



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

 Nirmus omatus Grube, v. Middeudorffs sibir. Reise zool., vol. i, p. 



477, pi. i, fig. 4. 

 Nirmus lineolatus Nitzsch, Burmeister, Handb. Eutomol., 1838, vol. 



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



culiues, 1880, p. 199. 



I have taken this common Nirmus of the gulls from 

 Larus argcntatus smithsonianus, brachyrhynchus, glau- 

 cescens, canus, vegce, occidentalis, heermanni, californicus, 

 dclewarensis (Bay of Monterey, California). Nitzsch 

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

 and Piaget on argcntatus and glaucus. 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. Sol, 2d See., Vol. VI. (8) March 13, 1896. 



