PAECECANTHUS. 261 



PAECECANTHUS, Sauss. 



Parcecanthus, Saussure, Rev. et Mag. Zool. 1859, p. 317*; Miss. Scient. Mex., Orthopt. pp. 465, 



468 ; Melang. Orthopt. 6 e fasc. pp. 647, 733. 

 Carsidava, Walker, Cat. Derm. Salt. i. p. 53 (1869). 



A well-characterized genus : the females by the flattened, short ovipositor (Tab. XIII. 

 fig. 34), the males by the interrupted zigzag stridulating vein of the elytra (Tab. XIII. 

 fig. 9, A)f. The genus seems to be confined to Central America and the northern parts 

 of South America. The limits of the species are somewhat uncertain, on account of 

 the variability of the characters. The coloration is of but slight importance, except in 

 One case (P. niger), all the species being fulvous in colour, with more or less numerous 

 black marks on the elytra, these markings sometimes becoming obsolete. The antennae, 

 head, and pronotum vary in colour, the head and pronotum being sometimes brown or 

 chestnut-brown. The anterior tibiae have always an elliptic, membranaceous tympanum 

 on their outer side (instead of on the inner side, as in Orocharis). The tympanum of 

 the inner side assumes various forms according to the species, but it is somewhat 

 variable in shape. When it is very narrow and long, it can apparently be closed by the 

 contraction of the tibia, so as to be reduced to a ridge (this may, however, be due to 

 contraction after death). In some cases the inner tympanum is quite obliterated and 

 replaced by a superficial sulcus or by an elongate depression. It is difficult to say 

 whether these differences are specific or not. The ovipositor is of a special type, as in 

 Heterecous (Tab. XIII. fig. 34). The tympanum of the male elytra is very different 

 in form from that of Orocharis, the true oblique veins being well-developed, five or six 

 in number, elongate, longitudinal, and somewhat undulate, divided into two groups, 

 the last two veins anastomosing with the base of the diagonal vein and the others 

 issuing from the stridulating vein ; while in Orocharis and Apithes there are only two 



transverse veins. 



Synopsis specierum J. 



a. Corpus gracillimum. Pronotum quam latum longius. Elytrorum $ speculum longius quam 

 latum, rhomboidale, anterius acutangulum ; vena stridulans transversa. Tibiae anticae 

 tympano extus elliptico, intus lineari. — [Jallax, Sss. (Cuba) .J 

 aa. Corpus haud insigniter gracile. Pronotum latius quam longum. Elytrorum speculum 

 ovatum, anterius obtusum; vena stridulans in zigzag fr acta, 

 b. Species fulvo-testaceae ; elytris frequentius nigro-notatis. 



c. Tibiae anticae in latere interno tympano membranaceo nullo. 

 d. Statura magna. 



e. Alae elytris sequilongae. Tibiae anticae intus puncto impresso notatae. — 



1. toltecus, Sss. 

 ee. Alas caudatae. Tibiae anticae intus sulco notatae. — 2. aztecus, Sss., var. 



* Incorrectly printed " Paroccanthus." f Except in 0. fallax, Sss., which is a somewhat peculiar type. 



t P. lituratus (Walk.), from Nicaragua, is so imperfectly described that its characters cannot be given. 

 (Comp. p. 265.) 



