Longicorn Coleoptera of Tropical America. 121 



some of which latter the prosternum between the coxae is also 

 reduced, as in Sphecomorpha, to a narrow thread, Stenopte- 

 rus mnrinus of Kluf^, which I venture to associate with the 

 typical species, bridges over the difference between it and 

 Odontocera and Acyphoderes. In both the narrowed part of 

 the subulate elytra is of extreme length and tenuity, ending in 

 a sharp point. The thorax in Sph. murina is not so broad as 

 in Sjjh. chalyhea, but it is of similar shape ; and the third anten- 

 nal joint is relatively not so long. 



1. Spliecomorplia chalyhea^ Newm. 



Sphecomorpha chcdyhea, Newman, /. c. p. 396. 

 S. bipluffiatus, Lacord. /. c. p. 472, note. 



Amazons ; Surinam ; " Brazil " [Newm.). 



The species is deceptively similar to Synoeca cyanea, F., 

 a common wasp in the countries where tlie Sphecomorpha is 

 found. 



2. Sphecomorpha murina, Klug. 

 Stenopterus murinus, Klug, Entom. Bras. Specim. alter, p. 55, t. xliv. f. 8. 

 Rio Janeiro. 



The abdomen is much attenuated at the base, and remark- 

 ably vespiforra in both sexes. 



Genus ISTHMIADE. 



Thomson, System. Ceramb. p. 106 ; Lacord. Gen, vol. viii, p. 504. 



The elytra are subulate (narrower than in Acyphoderes). 

 The antennse have all joints elongate and slender, strongly 

 serrate from the sixth joint. The thorax is narrow, strongly 

 polished, and tuberculate. All the species are mimics of 

 Ichneumon flies of the group Braconidse. 



1. Isthmiade hraconides, Perty. 



South Brazil. 



2. Isthmiade rubra, n. sp. 

 I. castaneo-rufa, nitida, vertice nigra; elytris disco pallide fuscis 



vitreis ; alls pallide fuscis, ante apicem fascia fulva. Long, 7-8 



lin. cJ ?• 



Prov. Rio Janeiro et Parantl, Brazil {coll. W. W. Saunders, 

 Dr. Baden, and H. W. Bates). 



Very similar to /. hraconides (Perty), differing in its bright 

 glossy chestnut-red colour, and especially its pale brown 



^ terus braconides, Perty, Del, An. Art. Bras. p. 94, t. 19. f. 3. 

 Isthmiade heph<xstionoides, Thorns, /. c, p, 1G6, 



