52 CLASSIFICATION OF THE ALEYRODID/E. 



Realizing this, Riley and Howard made a careful description of the 

 form. The material upon which their descriptions were based is 

 preserved in the bureau collection, and the following includes a study 

 of this same material. Unfortunately, a slight marking on the fore- 

 wings of the species was not considered of importance by Riley and 

 Howard, as it was no doubt overlooked by Curtis. This oversight 

 has led Cockerell into the error of redescribing the form as hid esc ens. 

 Now, however, that Riley and Howard's specimens, Cockerell's types, 

 and many other examples are at hand for study, there is little doubt 

 that all these forms are the same species. 



DESCRIPTIVE REMARKS. 



Pupa ca.'ie. — The pupa cases representing the Riley and Howard 

 material and those composing Cockerell's types, as well as numerous 

 others, are identical in structure as follows: The case (PI. XII, 

 fig. 2) is surrounded by a row of bristle-like hairs inserted on the 

 dorsum just within the margin. There are usually 13 of these to a 

 side. One pair of long, prominent caudal hairs is also present. 

 Margin entire, and within it all around (PI. XII, fig. 7) is a row of 

 large, simple, boat-shaped pores and the submarginal area is covered 

 with very many minute, simple ones. Along the median thoracic 

 region there are four pairs of small tubercled setae and on the cephalo- 

 lateral portion a pair of large compound pores of the type illustrated 

 in Plate XII, figure 6. The abdominal region has along each side 

 four large compound pores similar to the thoracic pair, and on either 

 side of the vasiform orifice are two reduced ones. The vasiform 

 orifice is nearly cordate and just cephalad of it is a pair of seta*, one 

 on each side. The operculum is subelliptical, broader than long, and 

 armed caudad with two prominent bristles. The lingula is conical, 

 exserted, and possesses two pairs of bristles. Both operculum and 

 lingida are minutely setose. 



On the underside (PI. XII, fig. 3) the mouthparts, legs, and 

 antennae are distinct. The trophic tubercle is large, the labium quite 

 distinct, Avhile the seta? are usually carried in the form of a loop. 

 The antennce are of two segments, 0.33 mm. long, and the proximal 

 segment is short, subcylindrical, and unarmed. The distal one is 

 much longer and annulated. At its distal end a short unguis is 

 present and at the base of this a fringed sensorium. The legs are 

 short, thick, of two segments, and armed with a solitary curved claw 

 (PI. XII, fig. 4). 



There is considerable variation in the size of the pupa cases, and on 

 this ground it might be possible to separate ir'idescens from cocois. 

 Since, however, we have considerable ditference in the cases of the 

 latter species, depending upon locality and food plants, it seems 

 hardly justifiable to select the larger specimens and call them a differ- 



