364 NEW YORK STATE MUSEUM 



white. On each side is a trianguhir shaped spot which marks 

 the position of the future respiratory fihmients of the 

 pupa. The basal half of the thoracic proleg is fuscous, its 

 apex paler. Extending from the base of the proleg to the first 

 abdominal segment is a broad, dark line with sinous margins. 

 The abdomen is fuscous, paler at the sutures and on the ventral 

 surface. The underside of the last two or three segments is 

 nearly white. The hooks (about 100 rows, 12 in a row) forming 

 the margin of the sucker are dark brown [pl.34, fig.11-12]. In 

 some specimens a fine fuscous line extends the whole length of 

 the ventral surface on the median line. Just before pupation the 

 developing ventral hooks of the pupa become visible. Though 

 retracted in nearly all the material studied, I have found that 

 the blood gills of the last abdominal segment consist of three 

 unbranched lobes. 



Pupa [pl.31, fig.lO]. Rich brow^n in color; the two tufts of 

 thoracic respiratory filaments (one tuft on each side) are each 

 divided primarily near the base into four main branches, the 

 two inner ones larger than the outer ones, each branch again 

 dividing two or three times into twigs, so that upward of 60 

 filaments may be counted. On the ventral surface close to the 

 posterior margin of the last six abdominal segments are four 

 larger upward curved spines; on the dorsal surface near the 

 base of each abdominal segment is a close row of spines pro- 

 jecting caudad, and on the dorsal and lateral surface of these 

 segments, a short distance from the margin, is a row of fine 

 spines projecting ce])halad. The last named are not quite so 

 close to the margin, nor are they nearly as large. In the figure 

 the segments are contracted, and the caudad projecting spines 

 appear to be attached to the posterior margin, whereas they 

 belong to the middle of the dorsal surface of the following seg- 

 ment. At the apex of the last segment are two stout hooks 

 projecting dorsad and cephalad. The pupal cases consist of a 

 dark matted mass of silk, of no definite form, secreted on the 

 rock, and in which the pupae are partially imbedded. The pupal 

 life lasts about eight or nine days. 



From Professor Kellogg (Leland Stanford Jr University, Cal.) 

 I received specimens of larvae and pupae which agree very 

 closely with those just described. These specimens (collected on 

 the university campus) appear to differ only in that the labium of 

 the larvae possesses but three bristles in each row on the ventral 

 surface. Specimens from Professor Aldrich (Idaho) are identical 

 with those from New York State. 



