64 CALIFORNIA ACADEMY OF SCIENCES. 



with distinct suture, often with a broad uncolored anterior 

 and lateral margin; signature usually shield-shaped, with 

 acuminate posterior angle ; prominent movable trabecular 

 reaching to or beyond end of the first antennal segment; 

 antennas similar in the sexes, with thick first segment, 

 segment 2 the largest, and segments 3-5 subequal. Thorax 

 with meso- and meta-segments completely coalesced; legs 

 rather flattened, insertions approached; front legs small- 

 est and usually concealed beneath the head. Abdomen 

 usually oval, of nine segments of about equal length; last 

 segment of male rounded, of female small and emargin- 

 ated. Color and markings whitish on buffy ground, 

 markings clear light brown to opaque dark brown, and 

 even to black; head with antennal occipital bands ; thorax 

 with lateral borders; abdomen with lateral bands, dark- 

 est, and lateral transverse blotches, longest in male where 

 they nearly meet on the median line. This genus has 

 been found on birds of all the larger groups except the 

 Gallinee. 



Genus Giebelia Kellogg. (Plate xi.) General char- 

 acters oi Docof horns; forehead (labrum?) with a broad 

 transparent membranous flap extending across the ventral 

 surface of head and projecting conspicuously beyond lat- 

 eral margins of head in the male and but slightly in the 

 female; rectangular anterior angles of temporal region 

 with large eye in the angle. Found, as yet, only on the 

 genus Piiji nits (Shearwaters). 



Genus Nirmus Nitzsch. (Plates v and vi.) Body usu- 

 ally narrow and elongate, though not actually long, the 

 species rarely exceeding 3^ mm. in length; the antennas 

 similar in the sexes; clypeal suture ordinarily indistinct; 

 the trabecular wanting, or if present very small, incon- 

 spicuous and not movable (rarely large and feebly mov- 

 able) ; other characters approximately those of Doco-phor- 

 us. Found on all kinds of birds. 



