190 UNIVERSITY OF COLORADO STUDIES 



2. Body pale pea-green; middle of back with a double crest of long erect white 



lamella?; tibia very long (Organ Mts., N. M., on Garrya) . . garrya, ckll. 



Body not so colored ........... 3 



3. Back covered by white secretion ......... 4 



Back not wholly covered by white secretion; more or less (often much) of the 



skin visible ........... .. r 5 



4. Legs and antennae sepia brown, of nearly the same shade throughout; secretion 



more compact than usual; eighth antennal joint the longest (Organ Mts., 



N. M., on Cheilanthes fendleri) ..... cheilnnthi, tinsley. 



Legs and antennas dark red-brown; third antennal joint the longest (Embudo, 



N.M., on Artemisia) ....... artemisia, CKLL. 



Legs and antennae dark brown, the femora and tarsi normally much darker than 



the tibiae (New Mexico and Colorado, usually on Atriplex) . . ■ anna, CKLL. 



5. Ovisac very long, when well developed 10 mm.; third antennal joint longest, or 



third and eighth equal (Mesilla Valley, N. M., on grass) . graminis, tinsley. 

 Ovisac much shorter ........... 6 



6. Dorsal surface naked, except for a very little mealy powder, and two median rows 



of small white waxy tufts (Organ Mts., N. M., at roots of grass) monticola, CKLL. 

 Dorsal secretion not arranged so as to form two separate lines of tufts (New 

 Mexico, on Gutierrezia) ....... nigrocincta, CKLL. 



MONOPHLEBINiE 



With a long posterior ovisac ...... Icerya, signoret 



Without any ovisac ........ Palaococcus, ckll. 



ICERYA, SIGNORET. 

 Southern New Mexico, on Larrea and Prosopis .... rileyi, CKLL. 



PALiEOCOCCUS, ckll. 

 Fossil at Florissant ........ simplex (scudder) 



Living species of New Mexico ......... 1 



Female about 5 mm. long, 4 broad, 3$ high (on Gutierrezia, Hymenoxys, 



Grindelia and Bahia, in the Upper Sonoran zone) . . townsendi (ckll.) 



Female about 6$ mm. long, 5$ broad, 5 high; back with very distinct yellowish- 

 white protuberances (on Pluchea borealis, in the Middle Sonoran zone) 



. pluchea' (ckll.) 



MARGARODINiE 



Subterranean; anterior legs of both sexes adapted for digging Margarodes, GUILDING 



MARGARODES, guilding. 

 Species of the Mesilla Valley, N. M. . . . . . . hiemalis, CKLL. 



