396 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Female differs from the male as follows: No metallic blue on vertex and 

 very little on the frons, which is cream color anteriorly. No black border to 

 the labrum. Spines of the posterior (inner) row of the third tibia? very little 

 shorter, no stouter, but slightly more numerous (18) than those of the ante- 

 rior row. Abdomen not narrower at 3. Appendages twice as long as 10, 

 shorter than 9, straight, dark brown. The faint yellow of the wings is better 

 marked between the nodus and pterostigma in one female; hind wings with 

 the dark brown streak at the base of the subcostal and median veins half-way 

 or more to the first antenodal, and a deep yellow cloud from submedian 

 vein to a short distance beyond the apex of the membranule ( 1 female), or to the 

 hind margin of the wing (1 female), and whose distal boundary is the submedian 

 cross-vein and distal sub-basal sector (of Kirby). Pterostigma paler. No 

 post-triangular cell reaches across the entire width of the field in the hind 

 wings, where the larger female has three cells, then two rows. 



Dimensions: Total length, $ 43-45 mm., ? 42.5-45 mm-; abdomen, S 

 30.5-35 mm., $ 31-32.5 mm.; front wing, i 33-35 mm., 2 35-5-37 mm.; 

 hind wing, $ 31.5-33 mm., 9 34-35-5 mm.; pterostigma 2.5-2.75 mm.; 

 superior appendages, & 2 mm.; appendages, ? 1 mm.; hind tibia 5.5 mm. 



i & Tepic, Oct., 1894, Eisen and Vaslit. 



Besides the male from Tepic, quoted above, I have, with 

 the permission of Mr. Samuel Henshaw, used, as types 

 of the above description, the following specimens in the 

 Museum of Comparative Zoology, Cambridge, Mass. : — 



One male, Acapulco, Mex., by A. Agassiz; one male 

 (last six abdominal segments lost) and two females, Isthmus 

 of Tehuantepec, by F. Sumichrast; one male (badly dam- 

 aged, head lost) Guatemala, Coll. Van Patten. 



The specific name t'nacula was chosen instead of obtusa 

 to avoid the use of a name which has already been twice 

 employed in the Odonata. Inacuta refers to the blunt apex 

 of the superior appendages of the male, a character not 

 possessed by any other Macrotkemis. 



32. Trithemis basifusca Calvert. 



Trithemis basifusca Calvert, Proc. Cal. Acad. Sci., 2d Ser., Vol. IV, 

 1893-94, P- 536, PL XVI, figs. 58-61. 



Male diners from the types from Baja California in that the basal spot of 

 the hind wings is paler brown and usually does not extend outwards quite as 

 far as the first antenodal, in extreme cases barely reaching the submedian 

 cross-vein. Like the types, the labrum is blackish with a narrow yellowish 



