522 WHEELER. 



Collection (U. S. Nat. Mus.). They differ so much from the corre- 

 sponding phases of apicidahnu that occidcnialc can no longer be 

 regarded as a mere variety of the former, but must be elevated to 

 specific rank. Comparison of the female and male of occidentale, 

 however, with those of the European L. microcephahim may show 

 closer affinities with this species, as a variety of which Emery origi- 

 nally described occidentale. The following descriptions are drawn from 

 two females and a male : 



Female. Length 10-10.5 mm.; wings 11.5 mm. 



Much smaller than apicidatum and with much shorter wings (length 

 of apiculatum 12-14 mm.; wings 17-18 mm.) and differing also in the 

 following characters: The head, excluding the mandibles, as long as 

 broad; with the scapes not reaching to the posterior corners, the 

 frontal groove very sharp and distinct and extending from the frontal 

 area to the anterior ocellus. Thorax through the wing insertions not 

 broader than the head, the flattened mesonotum distinctly longer 

 than broad. Surface of the body shining, though coarsely shagreened 

 and sparsely punctate. Hairs short and rather numerous, but much 

 shorter and less abundant than in apiculatum. Color ferruginous 

 brown, gaster darker, lower surface of head, thoracic sutures and legs 

 paler and more yellowish. Wings whitish hyaline, not infuscated as 

 in apiculatum, with paler veins and brown stigma and subcostal vein. 



Male. Length 9 mm.; wings 10 mm. 



Differing from the male apiculatum in its smaller size, shorter wings 

 and antennae (length of apiculatum 9-11 mm.; wings 14 mm.), with 

 the wings pale like those of the female, the gaster, legs, genitalia and 

 antennae reddish brown and the hairs, especially on the head, thorax 

 and legs conspicuously shorter and less abundant. The volsellae of 

 the genitalia are shorter and their tips slightly crenate along the dorsal 

 border, whereas this border is smooth in apiculatum. 



L. occidentale is very abundant among live oaks at low altitudes in 

 the Coast Range of California but less common in the Sierras. It 

 seems not to occur on their eastern slopes, judging from my inability 

 to find it in the Lake Tahoe Region. Only a few colonies were seen 

 in the Yosemite; at Wawona it was more abundant. 



76. Tapinoma sessile Say. 



Washington: Almota (A. L. Melander); Orcus Island, San Juan 

 Island, Pullman and Ellensburg (W. M. Mann); Rock Lake. 



California: San Jose and Palo Alto (H. Heath); Lompoc, Mt. San 

 Jacinto, Harris, Humboldt County and summit of Mt. Wilson (J. C. 



