January 1891.] 



PSYCHE. 



lobes' of the pronotum and upon the 

 sides of the head. Latipennis differs in 

 coloration distinctly from the two last 

 mentioned species but only slightly from 

 niveus. Like the latter its general color 

 is ivory white with the elytra perfectly 

 transparent but it is distinct from niveus 

 and the other two species in having the 

 head and basal half of the antennae suf- 

 fused with pink or light brown. It also 

 lacks very generally if not always the 

 small fuscous spots which are to be 

 found always in the other species, 

 except in the case of the black variety 

 of fasciatus* on the lower face of the 

 two basal joints of the antennae. 



Niveus is also distinguished from all 

 other species by its proportionally longer 

 maxillary palpi. This disproportion is 

 most apparent in the ultimate joint, 

 which is not onlv relatively but actually 

 longer than the same joint in latipennis, 

 a decidedly larger insect. These dimen- 

 sions are for the two species respectively : 

 fifth joint 1.5 mm and 1.4 mm; fourth 

 joint 1.3 mm and 1.3 mm; third joint 

 1.6 mm and 1.7 mm. Finally in niveus 

 the outer or fourth curved oblique nerve 

 at the base of the elytra is more angular 

 than in any of the other species and con- 

 sequently the distance between the third 

 and fourth nerves which in the other 

 species is about equal to that between 

 the first and second, and the second and 

 third nerves, is in itiveus much greater. 



In addition to the distinctions already 

 mentioned fasciatus has longer antennae 

 than the other species have, since these 

 organs are rather more than two and one 

 half times the total length of the bodv, 



and the larger spines at the tip of the 

 posterior tibiae are unusually strong and 

 acute. The ovipositor of the female is 

 also plainly distinct from the perfectly 

 straight ovipositor of niveus in being 

 distinctly turned up at the tip. The 

 maxillary palpi also offer distinct 

 specific characters in the proportionally 

 short fourth joint and in the subclavate 

 fifth joint which in the other species 

 is fusiform. Angustipennis differs 

 from the other species in its small 

 head and slender pronotum, which in the 

 female especially is decidedly narrowed 

 anteriorly instead of being of equal width 

 throughout as in the females of niveus 

 and latipennis. The hind legs are pro- 

 portionally longer and more slender than 

 they are in the allied species and the 

 post-tibial apical spines are so weak as 

 j-o be somewhat difficult to count with 

 the unaided eye. 



These species differ from one another 

 as markedly in song as in structure. 

 That of niveus is the well known 

 t-r-r — r-e-e: t-r-r — r-e-e, repeated with 

 out pause or variation about seventy 

 times in a minute. In the vicinity of 

 Davenport, Iowa, this song is heard as 

 early as the twenty-third of July and it 

 continues until the persistent little song- 

 sters are killed by the heavy frosts of the 

 late fall. This song is heard only at 

 night and occasionally on cloudy days 

 but in the latter case it is only an isolated 

 song and never the full chorus of the 

 night song produced by many wings 

 whose vibrations in exact unison produce 

 that characteristic "rhythmic beat " — as 

 Burroughs has happily phrased it. It 



