386 NEW YORK STATE MUSEUM 
intermediate ones short [p1.35, fig.2], and there are six bristles 
in each of the two longitudinal rows on the ventral surface. 
The three blood gills at caudal end are unbranched. 
Pupa. The thoracic respiratory filaments each consist of a 
single main trunk, from which arise eight branches, each of 
which divides into two, thus making 16 twigs in all [p1.35, fig.1]. 
Near the basal margin of the last few abdominal segments, are 
a few caudad projecting dorsal hooks, and on the tip of the last 
segment is a pair of blunt spines. The pupal case is of the 
wall pocket type, from which the respiratory filaments of the 
pupa project. Judging from the number of respiratory fila- 
ments of the pupa, the species described by Osten Sacken in 
American Entomologist, volume 2, seems to belong here. 
Simulium sp. C. H. Townsend 
Am. Ent. Soe. Trans. April 1893. 15:45 
The larva and pupa of a species which appears to differ from 
S. var. piscicidium, are described by Townsend [loc. cit.], 
the only species with which it might be confused. Specie 
characteristics are as follows: 
On the dorsal surface of the héad are several rows and groups 
of nearly concolorous markings ... Antennae pale, nearly as 
long as one half anterior width of head, three jointed, first joint 
very elongate, and narrow, not swollen, slightly curved, with a 
somewhat faint transverse suture on basal two fifths, cylindric 
below suture, beyond the suture very slightly and somewhat 
irregularly narrowing to tip; second joint narrower than tip of 
the first, straight and of equal width except slightly widened at 
base, a little more than one third as long as first joint, and with 
two small, triangular budlike processes, one on each side at the 
base, springing from the junction of the two joints and approxi- | 
mated to the second joint; third joint extremely small, short, 
minute, triangular, but little longer than wide, about the same 
shape as the minute processes at base of second joint. Fans 
consisting of about 60 scythe-shaped rays each, microscopically 
thinly hairy . . . Mandibles furnished with teeth on inner side 
at apex; four large teeth on apex, nine or 10 teeth behind these, 
gradually decreasing in size, except that the second of these is 
larger than the first, a large tooth still behind these; with a 
small one directly beside it . . . Thoracic proleg with at least 
30 obliquely longitudinal rows of hooks, and probably more; at 
base of these there is a marginal transverse row of bristles on 
side toward body (the leg being flexed forward) extending 
around laterally, but wanting on outer surface . . . Blood gills 
a soft, retractile, primarily three branched organ just anterior 
