AMERICAN COLEOPTERA. 107 



The male has the anterior tarsi as broailly dihiteJ as in any TucJii- 

 nits. The genital apparatus is also provided with two long, slender, 

 falciform processes which greatly resemble the lacinioe formed by the 

 deep division of the seventh ventral segment of Tarh. memnoniuH 

 and others. 



Occurs not rarely in the decaying stems of various CactaccEe in 

 Arizona. 



ERCIIOMIJS Motsch. 

 The species of this genus were placed originally by Erichson as a 

 group of Tachinm characterized by the carinate mesosteruum and the 

 simple anterior tarsi of the male. These have justly been considered 

 to have generic value and the group has consequently been known 

 as Copi-oporuK, Kraatz, (1859), although Motschulsky's name has one 

 year priority. 



The species may be separated in the following manner : 

 Elytra distinctly punctulate. 



Last ventral % triangularly notched. 



Thorax not visibly punctulate, elytra distinctly alutaceous inflatns. 



Thorax distinctly punctulate, elytra not alutaceous pillictipcuuis. 



Last ventral %, semicircularly notched. 



Thorax minutely punctulate, elytra not alutaceous vciltriculus. 



Elytra smooth, not punctulate. 



Last ventral % triangularly notched IseTis. 



E. inflatu$>>, (Fauvel mss.) n. sp. — Pitchy black, shining. Antennae rufo- 

 piceous, lour basal joints paler. Head black, extremely finely alutaceous. 

 Thorax similarly sculptured. Elytra conjointly broader than long, gradu- 

 ally narrower from base and emarginate at middle, surface finely punctu- 

 late and alutaceous. Abdomen sparsely punctulate and finely alutaceous, 

 beneath more distinctly punctulate. Legs rufo-testaceous. Length .12 — .14 

 inch; 3 — 3.5 mm. 



Male. — Last ventral deeply triangularly notched at middle. Last dorsal 

 quadridentate, the teeth slender and acute, the two middle longer. 



Female. — Last ventral divided into six slender processes, the outer very 

 short, the middle longer. Last dorsal with four slender acute jirocesses, the 

 middle longer. 



This species is much larger than the others of the genus and 

 broader and at the same time rather more depressed. 



Occurs under decaying Cactus at Camp Grant, Arizona. 



E. piinotipcnniM, Lee. — Black, shining. Head and thorax minutely 

 punctulate, very indistinctly alutaceous. Elytra distinctly punctulate, not 

 alutaceous, obsoletely longitudinally strigose. Abdomen minutely punctulate, 

 obsoletely alutaceous. Legs piceo-rufous. Length .10 inch; 2.5 mm. 



Male. — Last ventral broadly triangularly emarginate. Last dorsal quadri- 

 dentate, middle teeth longer, (fig. 28). 



Female. — Last ventral very like Tachinus angustatus ; last dorsal as in the 

 male. 



