EMBIOPTERA OF THE NEW WO'RLD ROSS 473 



cedar-covered, limestone plateau. A number of species of trees pres- 

 ent {Sdbina sahinoides, Quercus spp., Ulmus crassifolia, etc.) har- 

 bored colonies of the insect. One old oak stump 15 feet high, with 

 loose, deeply grooved bark, was found so thickly populated by the 

 species that it glistened white with an almost continuous covering 

 of silk. In general, however, the species seems to establish isolated 

 colonies here and there on the trunk which are occupied by a single 

 female and its brood of young. The species probably has an extensive 

 range throughout much of the cedar-oak as well as in the post-oak 

 associations of the region. It has not yet been found in the adjacent, 

 mesquite-covered lowlands in spite of a careful search. 



The food appears to be the lichens and moss through which the 

 tunnels are spun. This is evidenced by the green color of the fecal 

 pellets. The tunnels ramifying on the outer surface of the bark 

 lead to a more protected retreat such as a crack in the bark or one 

 between exfoliating bark flakes. Here the female constructs a larger, 

 more densely spun tunnel, covered with feces, in which the eggs are 

 laid. 



As far as could be ascertained during the limited period of obser- 

 vation, the males and females are all in their penultimate instar late in 

 July and early August and mature by the middle of August. The sex 

 ratio seems to be 1:1. The eggs are laid during the remainder of 

 August and early in September. Development probably begins during 

 fall, and a considerable time may be spent in hibernation. 



Anisenibia texana (Melander) was found at times sharing the 

 habitat of melanura but appeared to require the greater protection of 

 loose, dead bark under which it could spin its tunnels. At the time 

 TYielanura was maturing, texana had already mated, the males had 

 died, and the young were in the first or second instars. Of the two 

 species, melanura was by far the more abundant. 



The species of the genus Oligernbia heretofore have been known only 

 from single specimens or very limited series. The discovery of 

 melanura in large numbers affords the opportunity to examine more 

 closely certain features of the complex male abdominal terminalia. 

 All drawings of the terminalia were made for systematic purposes 

 and drawn from somewhat distorted KOH-treated specimens. The 

 untreated terminalia of this species reveal that all processes are con- 

 centrated toward the left to give length to the abdomen and sclerotic 

 support to the ejaculatory duct. The greatly produced left paraproct 

 forms the immediate ventral support of the duct and appears to be 

 itself supported by the mesal process of the left cercus-basipodite which 

 curves directly upward between the tips of the two tergal processes 

 (10 EPj and 10 LP), which curve downward and apparently function 



