156 CALIFORNIA ACADEMY OF SCIENCES. 



Menopon navigans n. sp. (Plate xiv, figs. 4 and 5.) 



Two males and a young female taken from a Short- 

 tailed Albatross, Diomedea albatrus (Bay of Monterey, 

 California). Piaget has found a Menopon (affine, 

 Tijdschr. voor Ent., 1890, vol. xxxiii, p. 248, pi. x, fig. 

 3) on an Albatross (Diomedea exulans, a skin in the 

 Leyden Museum), but my new species does not resem- 

 ble affine particularly. Affine is a smaller species, with a 

 head more than three-fifths as long as broad; the head of 

 the new species is twice as wide as long. 



Description of the male. Body, length 1.8 mm., width 

 .75 mm.; head and thorax pale with dark brown mark- 

 ings; abdomen with large, brown, transverse bands, sub- 

 parallel-sided; many long bending hairs. 



Head, length .34 mm., width .66 mm.; semilunar, 

 front with, on each side, three hairs (of which the second 

 is not strictly marginal), then a very short prickle, then 

 five hairs in front of the ocular region, of which three are 

 long; palpi and antennae projecting by the length of their 

 terminal segments; temporal margin with two very long 

 hairs, one half as long, two one-fourth as long, and a few 

 short ones; occipital margin concave with four hairs on 

 the middle third. Color, pale brown, darker medially, 

 and with black ocular blotches, and a linear, black, occip- 

 ital border. 



Prothorax broad, short, with lateral angles much pro- 

 duced and bearing two long hairs and a spine; posterior 

 margin flatly convex with ten hairs; color pale with a 

 brown transverse line and brown lateral angles darkest 

 outwardly, the margin of the latero-posterior sides being 

 black. Metathorax short, as broad as prothorax, pentag- 

 onal, posterior margin straight with a series of hairs closely 

 set, anterior angles and lateral borders expanding in pos- 

 terior angles, black; a broad transverse brown band like 



