424 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.54. 



Table of genera of Mengeidae. 



Wings having eight primary veins from base, with one distal detached vein be- 

 tween radius and medius and witli the second and third anal veins apically 

 united and a detached anal vein beyond these ; fifth and sixth antennal joints 

 short, not much longer than first and second 1. Mengea Grote. 



Wings having eight primary veins from base, with one distal detached vein be- 

 yond the tip of the radius, medius with two detached branches, third anal 

 faint; fifth and sixth antennal joints elongate 2. Triosocera Pierce. 



1. Genus MENGEA Grote. 



Correction to Bulletin 66, p. 207 : 



Lines 17, 18, 19. Grote, Augustus Radcliffe. *1S86. (Changes Triaena Menge 

 preoccupied, to Mengea, new name). Can. Ent., vol. 18, p. 100. 



Corrections to Genera Insectorum : 



Page 8, last line. Mengea. Grote, The Canad. Entom., vol. 18, p. 100 (1886). 



Page 9, lines 14-16. Mengea tertiaria, Grote, The Canad. Entom.. vol. 18, p. 

 100 (1886) ; Pierce, Bull. U. S. Nat. Mus. No. 66, p. 84, pi. 1, fig. 1 (1909) ; 

 Hofeneder, Bericht. Naturw. Med. Ver. Innsbruck, vol. 32, pp. 33-57, figs. 10-15 

 (1910). 



This genus contains one species, which was found fossil in amber 

 in Germany. 



1. MENGEA TERTIARIA Grote. 



The study of thoracic characters has enabled the writer to make 

 an interpretation of Menge's drawing and description of this species. 

 This drawing is necessarily arbitrary, but differs from Menge's 

 mainly in the addition of the postlumbium (pi. 64, fig. 1). 



This species differs principally from Triozocera by the length of 

 the last three antennal segments. In Mengea the fifth and sixth 

 joints are short, the seventh longer. In Triozocera these three joints 

 are subequal and elongate, the sixth being a little shorter than the 

 others. 



2. Genus TRIOZOCERA Pierce. 



This genus has several interesting characteristics. The facets of 

 the eyes are large and well separated. The head is not crowded. The 

 mandibles are reduced to a tiny chitinous filament and the maxillae 

 are one-jointed. The pronotum is arched forward in texana., but not 

 in mexicana. It is a simple band in both species. Mesonotum is 

 composed of two indistinctly separated transverse pieces. The meta- 

 scuti are not or at most only partially divided transversely to form 

 the parascutellar pieces. The mesopleurum is enlarged to form a 

 lobe under the base of the elytra, beneath which is the spiracular open- 

 ing. This location of the spiracle is entirely analogous to that in 

 Xenos. The tiny pro- and meso-coxae are loosely attached to lateral 

 hooks, which are apparently a fusion of trochantin, episternum, and 

 epimeron. The pro- and meso-trochanters are elongate. The meta- 



