67 
wide as the first and a little longer than the last, this about two 
thirds the width of the second. Mentum deeply emarginate, with 
acute lobes, very deeply bisulcate longitudinally. Median io e 
transversely corrugate. Lateral lobes with a short basal piece 
abutting against the cardo of the maxilla. Lateral lobes wit 1 a 
stout bristle at the anterior third; middle lobe with a smaller pair 
of bristles opposite apex of emargmation. Palpiger with a deep 
median sulcus, each side lobe bearing a stout bristle. 1 alpi two- 
l’oiiited, joints ovate, similar. Ligula rounded, curved upward at 
tip, a pair of stout bristles beneath, but otherwise smooth. 
Cervical shield pale brown, with a darker transverse line. Spi¬ 
racles nine, first and last especially large; all of them patent, lip 
of abdomen flattened or slightly concave on its dorsal surface, 
provided there with strong bristles, eight of which are borne by 
the last segment in two rows, and four m a single row by the 
preceding segment. 
S. parvulus. Larva. About 6 mm. long by 2.5 in width. Ex¬ 
cept for size, extremely like S. ochreus. Head much paler,—dull 
yellowish brown; clypeus yellowish; labrum concolorous with the 
occiput. Latter with diverging frontal vittrn, less closely approx¬ 
imate than in ochreus , forming a larger pale patch posteriorly. 
Sides of head beneath with an obscure pale longitudinal stripe. 
Frontal suture less sinuate than in ochreus ; its angle more acute. 
Frontal corrugations less conspicuous. Occipital black dashes not 
bordering the vitta externally. 
DISTRIBUTION. 
The general distribution of these species has been sufficiently 
indicated in the preceding synopsis; and concerning their occur¬ 
rence in this State, I need only say that all those treated in the 
present paper have been collected by us frequently, m Centia 
Illinois with the exception of rohustus, which is rare m our col¬ 
lections and has come to us only from the northern part of the 
State. S. pertinax w r as taken by . us also in Cook county neai 
Lake Michigan; canosus near Cairo and in Champaign county , 
and sculptilis at Villa Eidge, in extreme Southern Illinois. Placi- 
dus was obtained also in the northern part of the State, tiom 
Lake and Whiteside counties. 
LIFE HISTORIES. 
The life histories of only six of our North American species are 
even approximately known, that of parvulus most fully, and those 
of ochreus, pertinax, rohustus and costipennis , by detached obsei- 
vations ,—ochreus, pertinax, and costipennis being here first re¬ 
ported. 
Parvulus is certainly single-brooded, is known to hibernate as 
an imago, appearing in spring as early as March and Apri l-- and 
*This species was found by us not uncommon un 
in winter quarters, April 16, 1H87, at Edgewood, Ill. 
the larva was noticed in this Held. 
ler dead vegetation in meadows, evidently still 
Occasionally a timothy bulb hollowed out by 
