86 Journal New York Entomological Society. [Voi. v. 
tip of the lingua extending beyond the end of the maxillae. The 5- 
jointed labial palpi reach one-half way between the end of the lingua 
and the end of the maxillae; the joints of both pairs of palpi rapidly de¬ 
creasing in size; the maxillary palpi 6-jointed, reaching only to the tip 
of the maxillae, thus being much shorter than the labial palpi, whereas 
in the pupa of Andrena they reach to and are parallel with the tips of 
the other pair. All the mouth parts are twice as long as in Andrena , 
and in this respect Nomada seems more allied to Bombus , etc., but 
otherwise, and in its elongated body especially, it is much lower. The 
legs are slenderer than usual, the tarsi folded on the breast as usual, 
the hind legs only reaching to the middle of the abdomen, which is un¬ 
usually long and slender, the segments long, very convex, the sutures 
large, broad, deeply impressed, the hind edges much thickened, dentate 
beneath (not so in Andrena) showing that the pupa of this parasitic 
form probably moves about a good deal in its cell. On the hind edge 
of the 7th and 8th abdominal segments grow out a pair of tubercles, 
those on the 7th small and simple, the 2d pair (on 8th) very much 
larger and ending in a nipple-like papilla. The 9th sternite is 
square and slightly excavated at the edge, while the terminal (probably 
10th) tergite is elongated into an acute extensible point tipped with 
black. These rhabdites agree well in form and position with those of 
$ Andrena vicina ; they are, however, a little longer, more exserted, 
and the 10th tergite is longer, slenderer and more pointed. 
Thorax: The mesial groove and parapsidal grooves of the meso- 
thorax are deep and better marked than usual. The scutellum rises into 
two prominent tubercles which are larger than in Andrena , while the 
meta-scutellum is smaller, being small and scarcely tuberculated. The 
propodium is broad and flattened, contracting somewhat posteriorly. 
The hind tarsi are spinulated on the outer edge. 
9 differs from $ in the head being a little wider and the body 
thicker; the antennae are of the length and size in both sexes, though 
differing in the adult, and the mouth-parts are precisely the same. Tip 
of the abdomen: ovipositor with three pairs of rhabdites almost en¬ 
tirely exserted ; the tip is precisely as described in the $ , ending in an 
acute prolonged point, and the square end of the 9th urite forming the 
under side of the anus is the same as in the $ . (This identity in the 
pupa is interesting. The $ and 9 external genitals seem to be strictly 
homologous in position though the genitals of the $ only consist of two 
pairs of appendages (rhabdites) arising from the 8th segment. The $ 
has one abnormal segment more, this being absorbed in the 9. In the 
