B39 
or furrow around the entire body, which, with the lateral margin, 
forms a prominent, rounded ridge. The antenne are identical with 
those of the previous stage, except that they are somewhat longer. 
The anterior and middle tarsi are either wanting or are sometimes 
represented by a minute, squarish stump, which occasionally bears 
at its external angle two rather stout, outward-curved hooklets, evi- 
dently the representatives of claws, while the hind tarsi, in the major- 
ity of cases, are again quite normal; some specimens have one or two 
perfect claws, indications of claws, or none whatever; the tarsal digi- 
tules of the posterior legs may be well developed, rudimentary, or 
wanting. The mature insect may, however, be always recognized by 
Fic. 21.—Hamamelistes spinosus: a, young larva, first stage, fifth generation; b, larva, second 
stage; c, prepupa, third stage: d, pupa; e, return migrant; /, antenna—much enlarged 
(original). 
the formation of the last abdominal segment and the shape of the tail; 
in the immature specimens the tail is short, very broad, being either 
broadly arcuate or with an obtuse angle medially, while the last 
abdominal segment is semicircular and entire. In the adult female, 
however, the tail is small, transversely oval, knob-like, and bears two 
bristles, the last segment being strongly bilobed, each lobe bearing 
ten or more long hairs. The rostrum is short and reaches but slightly 
beyond the anterior coxze. The hairs of the head and body are simi- 
lar to those in previous stages, except that they are longer and stouter. 
Fifth or mgratory generation; first stage (Fig. 21).—Early in 
May the leaf-corrugating females or fourth generation of the series 
are fully matured and commence their reproductive functions. The 
