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XXIII. Descriptions of new species of Tenthredinidse and 

 Cynipidse /rowi, Mexico. By Petee Cameron. 



[Read September 3rcl, 1884.] 



The following paper (describing fourteen new species) 

 is supplementary to my work on the Hymenoptera of 

 Central America in Messrs. Godman and Salvin's 

 * Biologia Centrali-Americana.' The principal fact 

 recorded in it is the occurrence in Mexico of three 

 distinctly northern genera of saw-flies, namely, Ncmatus, 

 Eimra, and HemicJiroa, genera which have not hitherto 

 been recorded so far south. Among the Cynipidce the 

 genera Aidax, Eucada, and Megapelmus are also new for 

 the fauna. 



I am much indebted to Herr Eogenhofer, of the 

 Vienna Museum, for the opportunity of examining the 

 Mexican Hymenoptera of the Museum under his charge. 



TENTHREDINID^. 



Nematus mexicanns, n. s. 



Livid testaceoias ; face, sides and apex of abdomen above, and 

 legs, obscure livid yellow ; antennae, nietanotum, and back of 

 abdomen, except at apex, apex of hind tibiae and tarsi, black ; 

 anterior tibiae inclining to fuscous. Wings clear hyaline ; costa 

 and stigma v^hitish yellow. Antennae shorter than the abdomen, 

 almost glabrous ; 3rd joint a little shorter than 4th. Vertex raised 

 in centre ; frontal area a deep wide depression ; antennal fovea 

 large, longer than wide. Clypeus deeply incised ; palpi fuscous. 

 Wings longish ; 2nd cubital cellule double the length of 3rd, not 

 angled where the recurrent nervures are received ; 3rd cellule a 

 little widened at apex ; the 2nd recun-ent nervure received a little 

 in front of 3rd transverse cubital. Abdomen longer than the head 

 and thorax together, narrowed towards the apex ; its last segment 

 largely developed above ; cerci long ; ovipositor long, nearly half 

 the length of the abdomen ; the sheath at apex pilose. Blotch 

 email ; cerci large, white ; claws bifid, spurs shortish. The vertex 

 and mesonotum are very finely punctured ; on the middle lobe of 



TRANS. ENT. SOC. LOND. 1884. PART IV. (DEC.) 



