46 A CONTRIBUTION TO THE KNOWLEDGE OF 



which the derm is still membranous there is nothing that appears to cor- 

 respond with the white areas seen in adult specimens, but in specimens 

 where the derm is heavily chitinized these areas are seen to consist of a 

 non-pigmented region which surrounds a point of extra heavy chitiniza- 

 tion. Antennae (Fig. 21 F) very short and stout, five to six-seg- 

 mented. Legs likewise very short and stout but with all the parts recog- 

 nizable. 



First stage larva (Fig. 21 A) with two very small, stout spines and 

 a single very long spine in each stigmatic depression, the long spine 

 attaining nearly one-fourth the width of the body. Marginal spines quite 

 large, slender. Anal plates slightly reticulated. 



Notes : The original description is in error in the statement regarding the 

 white areas on the dorsum, as has already been pointed out. It is further in error 

 in the statement that the legs are lacking. 



Genus PROTODIASPIS Ckll. 



The original description of this genus is by no means as definite as 

 might be desired and it is not at all certain that all the species now 

 referred here are congeneric with the type. I am here naming two new 

 species which I am referring for the present to this genus. Although it 

 remains to be seen whether these are congeneric with P. paruula, there is, 

 I think, but little room for question that they are strictly congeneric with 

 P. anomala Green, an Australian species. It is an interesting point that 

 the latter species is from a species of Acacia and that one of the new 

 species is likewise from an Acacia and the other from a related genus, 

 Prosopis. 



Inasmuch as both the species here described were found only by the 

 purest accident, being hidden away in cracks in the bark with nothing 

 whatsoever to betray their presence, one can not but wonder how many 

 more of these tiny species still remain to be discovered. 



Protodiaspis tridentata n. sp. 

 Fig. 22. 



Type host and locality. From Prosopis velutina, five miles east of 

 Benson, Ariz. 



Habit. Found in crevices in the bark, its presence indicated only by 

 a roughening of the bark for which the insect is perhaps responsible. 

 No scale secreted, but there is a small amount of cottony matter. Adult 

 female contained within the derm of the preceding stage, which is heavily 

 chitinized and black in color. Larval exuvium lying at one side, likewise 

 black. Scale of male not observed. 



