On Certain Grass-Eating Insects. 89 



each joint. The tip of the valve has become more oval and the 

 harpe has been reduced to a recurved flattened process. A short 

 accessory spine occurs but it is very different from the accessory 

 spine of the Unistriatellus Group, The uncus is very similar to 

 that of C. agitatelliis and like it has suffered little reduction. The 

 genital plate is more specialized than in C. agitatellus. 



25. Cranibus flo)idus. See No. 14. 



26. Crambus laqueatellus. This species is undoubtedly a more 

 specialized form that has arisen from the progenitors of C. agi- 

 tatelliis or a closely allied form. The venation is almost iden- 

 tical, though the wing is a little narrower and exhibits a higher 

 degree of specialization. The antennae are more specialized. The 

 harpe has become shortened and strongly modified ; both the spur 

 of the harpe and the accessory spine are flattened concave pro- 

 cesses, while a chitinous bar extends across the base of the valve. 

 The uncus and the lower limb are well developed and closely re- 

 semble those of C. agitatelliis. The members of the scaphium are 

 loosely united and elongate. The genital plate is highly spe- 

 cialized and is similar to C. agitatellus. 



27. Crambus satrapelliis. This species has the narrowest fore 

 wings and the apex is most prolonged. The veins are independ" 

 ent and branch near the margin. The antennae are not very 

 highly specialized. The harpe is very efficient as is also the ac- 

 cessory .spine. The form of these organs connect this species with 

 C. laqueatellus. The uncus seems to have disappeared com- 

 pletely and a pair of very thick tufts of curved hairs has been devel- 

 oped. The other forms studied throw no light upon this singular 

 modification. A study of other species will probably throw much 

 light on this question. 



Thus far the classification has been based entirely upon mor- 

 phological studies. In no case has it been assumed that a species 

 has descended directly from any species now living. The refer- 

 ring of species to each other was only to indicate relationship ; the 

 connecting links between the species have disappeared in all prob- 

 ability. Behind these great modifications of the genital organs 

 there must be some plan, and if these forms have been rightly in- 

 terpreted, we might expect to find some vital relations between 

 closely allied species. In short, vital and morphorlogical facts 

 should harmonize. 



