78 HYMENOPTERA. 



SMICRA. 



Smicra, Spinola, Ann. Mus. xvii. p. 147. 



Spilochalcis, Thorns. Hymen. Scand. iv. p. 13. 



Conura, Sichel, Ann. Soc. Ent. Er. (4) v. p. 348, 1865 (ex parte). 



Chalets, Westwood, Intr. to Class. Ins. ii. Appendix, p. 65. 



This is one of the best-known and most widely distributed of the genera of Chalci- 

 didae. Species have been discovered in almost all parts of the world ; but they appear 

 to be especially abundant in Central and South America. The generic characters 

 appear to lie in the antennae being inserted in the middle of the face, and in the 

 abdomen having a more or less elongated peduncle — the former character separating 

 it from Epitranus and Chalcitella, which have a longish petiole ; and the latter from 

 Chalets and Halcitella. Conura (in part) differs merely from it in the apical abdominal 

 segments being prolonged into a " tail " as in Phasgonophora. I am very doubtful if 

 this latter character is a generic one ; the length of the " tail " depends upon the habits 

 of the insects, having reference (as in Torymus) to the situation in which the prey of 

 the Chalets is hidden : if it is easily reached, the ovipositor is short ; if more out of the 

 parasite's reach, it is lengthened in correspondence. I find, furthermore, that so many 

 gradations occur, say between an ovipositor of the length of that of Phasgonophora 

 thoraciea and an ordinary Smicra, that it is impossible to draw a line between them ; 

 and the difficulty of separating the genera in this group is increased by the fact that 

 the length of the petiole also varies, so that thus the line of demarcation between 

 Smicra and Chalcis is not always easily fixed. 



C. G. Thomson (I. c.) has divided the Smicra of authors into two genera — Smicra 

 (having for type the Sphex sispes, Linn.), distinguished by the thorax being entirely 

 black, and the middle tibiae without spurs ; and Spilochalcis, with the thorax more 

 or less marked with yellow, and the middle tibiae with spurs. According to this 

 definition, all the Central-American species known to me must be referred to Spilo- 

 chalcis ; but in the mean time I prefer to retain the older denomination. 



The species show considerable variation in structure, especially of the femora and 

 metathorax. The latter is usually divided by reticulations into more or less well- 

 defined fields, the form of which may afford good specific characters, as they do in the 

 Ichneumonidae ; but I am unable to say if their shape is constant in the same species, 

 not having long series of any of them. 



A. Femoral teeth large, blunt, 4 to 8 in number. (Species 1-10.) 



1. Smicra mexicana. 



Smicra mexicana, Cresson, Trans. Am. Ent. Soc. iv. p. 42. 13 x . 

 Eab. Mexico (Sumichrast 1 ). 



