AQUATIC INSECTS IN NEW YORK STATE 399 
CORETHRELLA Coquillett 
N. Y. Ent. Soc. Jour. 10:191 
Plate 40 
Through the kindness of Prof. John B. Smith of New Bruns- 
wick N. J. from whom I received specimens of larvae, pupae 
and adults, I have been enabled to make a study of this inter- 
esting species, which in the adult stage has already been 
described under the name of Corethra brakeleyi by 
Mr D. W. Coquillett. 
From Corethra it differs in the following particulars: 
In both the male and female the thorax, scutellum, abdomen 
and legs are sparsely covered with long coarse hairs, many of 
these being as long as the fore metatarsus. The antenna of the 
tale is thickly covered with long hairs arranged all along the 
shaft excepting on the apical half of the 13th, and all of the 
14th and 15th, which have only short hairs. The 15th or 
apical joint is slightly enlarged and conical [fig.8]. The an- 
tenna of the female has a circlet of a few long hairs at the base 
of each joint and another irregular circlet of somewhat shorter 
hairs on the middle of it. | 
~ In Corethra, at least in those species with which I am famil- 
lar, the male has one circlet of many long hairs at the base of 
each joint, standing nearly at right angles with the shaft. In 
the female these hairs are fewer and shorter; the second circlet 
of hairs wanting. In a balsam mount of Corethrella the 15 
antennal joints can easily be counted. The eyes are reniform; 
the palpi and proboscis are short, the former about twice as 
long as the latter; the metatarsus is longer than the following 
joint and the tarsal claws [fig.7] are simple and much curved. 
Corethrella brakeleyi Coquillett 
Larva. The larva resembles that of Mochlonyx much more 
closely than that of Corethra; it differs from the former in hay- 
ing the antennae attached near the middle line of the head at 
the extreme cephalic end, hinged so that (they move in a hori- 
zontal plane, and normally lie folded back against the side of 
the head, as shown in figure 1 and 2. The head is transversely 
oval. The antennae |fig.38] have three long curved spines and 
