50 



A CONTRIBUTION TO THE KNOWLEDGE OF 



able because of the crenulation of the margin of the pygidium, but their 

 position marked by the spines arising from their bases. Anal opening 

 somewhat nearer the anterior margin than the posterior. Tubular ducts 

 abundant, short and quite slender, their orifices arranged in no definite 

 manner. On the ventral side the wrinkling of the surface is confined to 

 an area near the margin, this area bearing many tubular ducts. No cir- 

 cumgenital pores. Vaginal opening quite small, close to the anterior 

 margin of the pygidium. Spines arising from the bases of the lobes 

 quite long and slender. 



Notes : Cockerell has described this species as a Diaspis but it certainly does 

 not belong to this genus. In fact, it does not belong in the group of genera of 

 which Diaspis is typical, being rather a member of the Aspidiotus group, the ducts 

 being entirely of the latter type. However, I can not assign it to any named genus 

 and I leave it in Diaspis for the present. 



Diaspis montana (Ckll.). 

 Fig. 25. 



Type host and locality. From Quercus wrightii, Pinos Altos, N. 

 Mex. According to the most recent authorities this is a synonym of Q. 

 pungens. 



Specimens examined. From Quercus emoryi, between Benson and 

 Dragoon, Ariz. 



Scale. Of the type common to the genus. 



Fig. 25. Diaspis montana Ckll.: pygidium. 



