- AQUATIC INSECTS IN NEW YORK STATE 321 
arranged in the form of a very irregular trapezoid [p1.26, fig.6] ; 
all the segments of the leg with many setae [p1.26, fig.5]; labrum 
indistinctly five sided, with eight marginal setae, the six median 
ones short, subequal in length, and equidistant from each other, 
the lateral ones long and distant from the median ones, with 
six discal setae, the distal pair in front of a line drawn between 
the median pair and about as long as the median pair, the 
median pair long and stout, the proximal pair very long and 
slender, the distal and median pairs in front of the distal pair 
of sensory pits, with two lateral setae which are long and stout, 
and with four sensory pits [pl.26, fig.38]; the anterior tergal 
setae of the mesothorax and metathorax divided into three 
groups, those of the first five abdominal segments not divided 
and their lateral extensions united with their supraspiracular 
setae, those of the sixth and seventh abdominal segments not 
divided and distinctly separated from their supraspiracular 
setae, the posterior tergal setae of the mesothorax: slightly 
joined with the lateral groups of the anterior tergal setae, those 
of all the other segments straight and distinct; the supraspir- 
acular setae not extending on to the annulet of the posterior 
tergal setae, those of the seventh abdominal segment not con- 
gisting of more than three or four setae; the infraspiracular 
setae of the abdominal segments of medium size, oblique, those 
of the seventh segment not reaching cephalad as far as the spir- 
acle; the anterior and posterior sternal setae of the thoracic 
segments distinctly separated, their posterior sternal setae di- 
vided longitudinally into two distinct groups; the pedal setae 
circular in outline and separated from the sternal setae; the 
sternal setae of the first five abdominal segments forming a 
continuous group, those of the sixth and seventh abdominal 
‘segments divided longitudinally, those of the seventh segment 
_ not consisting of more than three or four setae [pl.29, fig.4]. 
Cocoon. Brown; oval in outline; and attached along the mid- 
dle line of the leaf of a sedge (Juncus). Length, 11mm; width, 
6mm. 
Described from specimens loaned by the Museum of Compar- 
ative Zoology and collected by Mr H. G. Hubbard in marshes of 
Detroit river, Michigan, in August 1873. 
Donacia aequalis 
Larva. Mandibles bidenticulate, with one or two well marked 
teeth within [p1.26, fig.8]; eyes apparently wanting; each seg- 
ment of the leg with a number of long setae [pl.26, fig.12]; the 
labrum distinctly five sided, the front margin deeply emarginate 
