On Certain Grass-Eating Insects. 55 



tent organ or penis. (PI. VII, Fig. 10, pn.') Dorsad of the 

 penis and working vertically is a more or less beak-shaped organ, 

 the uncus. (PL V, Fig. 1, u.') Articulated with the uncus and 

 working vertically with it is a more slender Y-shaped organ, 

 Xho. lower limb of the uncus. (PI. VIII, Fig. 16, /.) The penis 

 extends between the branches and dorsad of the body of the 

 lower limb of the uncus. The uncus and the lower limb function 

 as vertical forceps, the clasps as lateral forceps. The uncus and 

 the lower limb are articulated to an inverted keel-shaped organ, 

 the scaphium. (PI. V, Fig. i, i'). The scaphium is composed of 

 a pair of sclerites the members oi the scaphium. (PI. VIII, Fig. 

 14, VI, -m.) In some species the two members of the scaphium are 

 loosely united. (PI. XI, Fig, 26, m, ;«) ; in other species the 

 scaphium seems to be composed of a single sclerite. In the 

 female the oviduct is guarded exteriorly by a pair of lateral plates, 

 \h& genital plates. (PI. V, Fig. 2, g.) The walls of the vagina 

 are chitinous and in some species there are chitinous processes 

 which are evidently correlated with the chitinous processes or 

 hooks on the penis. (PI. VII, Fig. 10, p?i.^ Later we will dis- 

 cuss the modifications of these organs in detail. 



SYNOPSIS OF SPECIES. 

 Three tables are given. The first is purely artificial and is 

 simply intended as an aid in the identification of the species. In 

 the second the period of flight of the various species is presented in 

 a condensed form. The third table is based largely upon a study 

 of the exterior genital organs ; in this table an effort is made to 

 indicate the afl&nities of the species. 



Tabi^e for the Separation of Species of Crambus. 

 A. Fore wings some shade of gray, not yellowish. 



B. Markings dark fuscous with brownish flecks, indistinct ; 

 size small ; male antennae not pectinate. PI. XIII., Fig. 2. 



2. caliginosellus.^ 

 BB. Markings quite distinct, a distinct subterminal line. 

 C. Only a blackish spot on the tip of the discal cell ; male 



antennae pectinate. PL XIII., Fig. 5. 5. miitabilis.'^^ 

 CC. An oblique rather irregular di.scal stripe ; size large ; 

 male antennae not pectinate. PL XIII., Fig. 3. 



J. interminellus ."^ 



■The species marked with an * were taken at Ithaca. 



