ZOOL— Vol. II.] PATTERSON— NOTES ON CEROCOCCUS. 393 



Cerococcus corticis Town. 



Plate XX II I, Figs. 23-28. 



Cerococcus corticis was discovered by Mr. Koebele, in 

 1897, on Querctcs engelnianni, in Nogales, Sonora. It is 

 between the two species described above in size and shape, 

 but resembles the former in being bright crimson and in 

 having conspicuous spiracles. A black fungus follows this 

 scale, rendering it less noticeable than it would otherwise 

 be. The covering of the insect is of white wax and is not 

 smooth on the surface, but is covered with fine filaments 

 which give it a cottony appearance. But two stages in the 

 development of this species were observed — the first stage 

 and the adult female. 



First Stage. — Like C . ehrhorni, these insects are vivipa- 

 rous. The young (fig. 23) are similar to those of the two 

 species described above, being elliptical in outline, distinctly 

 segmented, and having two caudal lobes. The latter, how- 

 ever, bear stiff hairs (fig. 24) instead of long filaments. 

 As with C. guercHs, the legs (fig. 25) are long, and each 

 is furnished with four knobbed digitules. The antennse 

 (fig. 26) are six-jointed like those of the last named species, 

 but are different from them in form. The first, second, 

 fourth, and fifth joints are nearly equal in length, the third 

 is slightly longer than the first, and the last about twice as 

 long as the first. 



Adult Female. — The adult female (fig. 27) is similar in 

 outline to the intermediate stage of C. qitercus. The ter- 

 minal segment of the body, though strongly chitinized, is 

 not so prominent as that of C. ehrhorni. The antennae 

 (fig. 28) are very small, unsegmented, about as broad as 

 long, and truncate at the tip, with eight bristles. 



