Mr. J. S. Baly on tJie Phytophaga. 455 



costatis. Antepectus angustum, integrum. Pedes : femoribus quatuor 

 anticis leniter, posticis sat incrassatis, subtus non canaliculatis ; tibiis 

 maris quatuor anterioribus extus ante apicem spina valida armatis, ilia 

 tibianim anticarum brevi ; tibiis posticis muticis, apice paullo incrassato, 

 extus excavato, introrsum curvato, in processum obtusum compressum 

 producto : FCEMiNiE tibiis anticis muticis, intermediis spina brevi armatis, 

 posticis apice introrsum non curvato, non producto, spina acuta armato, 

 tarsorum ejusdem paris articido basali ad apicem tibia? inserto. Tarsis 

 articulo tertio brevi ; posticis paullo ante apicem tibia? insertis ; ungui- 

 culis bifidis, dente interiore paullo breviore,compresso, introrsum curvato. 

 Type, Plectrotetra Clarkii, Baly. 



Plectrotetra Clarkii. (Plate XXI. fig. 3.) 

 P. elongata, subcylindrica, rufo-testacea, nitida; an tennis (basi excepta), 

 femorum basi, tibiis tarsisque nigro-fuscis ; elytris viridi-cyaneis, gemel- 

 lato-punctato-striatis. — Long. 3-3^ lin. 



Mas. Elytronun interspatiis alternis minus costatis, ante medium fere 

 planis, tarsorum anticorum quatuor articulo basali dilatato. 



Fcemina. Elytrorum interspatiis alternis valde costatis. 



Var. A. Antennis corpore concoloribus. 

 Hab. Oaxaca. Collected by M. Salle\ 



Elongate, subcylindrical, parallel, sbining rufo-testaceous ; antenna? 

 (their basal joints excepted), extreme base of thighs, the tibia? and tarsi 

 nigro-fuscous ; unguiculi rufo-piceous. Head prominent ; face nearly 

 perpendicular, trigonate ; epistome separated from the face by an ele- 

 vated line, from the apex of which a broad, strongly raised ridge extends 

 upwards as far as the upper edge of the insertion of the antenna?, where 

 it becomes dilated on the upper portion of the face into a raised, bilobed, 

 obovate space ; antenna? longer than the body in the male, shorter in 

 the female. Thorax transverse, sides moderately rounded, slightly 

 narrowed in front, all the angles slightly produced, acute ; upper surface 

 swollen, slightly flattened across the middle of the disk, the latter im- 

 pressed near its base with a sinuous transverse groove, either end of 

 which, before reaching the lateral border, curves obliquely to the 

 hinder margins; surface of disk nearly impunctate. Elytra rather 

 broader than the thorax, narrowly oblong, sides parallel, the apex 

 obtusely rounded, sutural angle acute ; surface of each impressed with 

 five or six double rows of punctures, the punctures being placed more 

 or less irregularly on the stria? ; interspaces between each double set of 

 stria? nearly flattened in front in the male, more or less costate towards 

 the apex, in the female costate for their whole length ; interstices 

 between the punctures on the stria? frequently transversely costulate. 



Genus Nonarthra. (Details, Plate XXI. fig. 1.) 

 Corpus rotundato-ovatum, convexum. Caput exsertum ; antennis 9-arti- 

 culatis, robustis, ad apicem subincrassatis, compressis, articulo primo 



