26G TERTIARY INSECTS OF NOETU AMERICA. 



Aphidopsis sp. 

 PI. 18, Fig. 11. 



A single specimen and its reverse is the only instance of an immature 

 plant-louse among the numerous remains of this family at Florissant. This 

 is excellently preserved, and agrees so well in the structure of the antennae 

 and legs and in the form of the abdomen with the species of Aphidopsis, 

 a 2)revailing type among the Florissant forms, that I venture to place it here; 

 the more so as in the markings of the abdomen, well represented on the 

 plate, it bears a striking resemblance to A. subterna, the most common 

 species of Aphidopsis. Short conical markings on the outer sides of the fifth 

 visible abdominal segment evidently mark the position of former cornicles. 



Length of body, 4™"' ; antennae, 4™"' ; fore legs, 3.7™'" ; femur, 1.6""" ; 

 tibia and tarsus, 2.1"""; middle legs, 4"""; femur, 1.3"""; tibia and tarsus, 

 2.7"™; hind legs, 3.5 ?™"' ; femur, 1.25 f"""' ; tibia and tarsus, 2.25"". 



Florissant. One specimen, Nos. 1044 and 4271. 



10. ORYCTAPHIS gen. nov. {6pvHT,k, Aphis). 



Fore wings with the stigmatic vein arising from the middle of the exceed- 

 ingly long and fusifoi'm but moderately broad stigma. Cubital vein (by 

 analogy with the others) twice forked, the first time very far from its origin 

 (which is nearlj' midway between the base of the first obhque and stigmatic 

 veins) and rather before than behind the base of the stigmatic vein (the 

 ])late is wrong in this respect), the second time uncertain, as the only speci- 

 mens are not well preserved here. Second oblique vein arising many times 

 nearer the first oblique than the cubital vein, so that the first discoidal cell 

 narrow at base is several times wider on the hind margin. Legs moderately 

 slender. Abdomen, as far as can be seen, relatively long and slender. 



Table of the species of Oryctaphis. 



Oblique vciu scarcely divergent iu basal b:ilf, afterwards distinctly divergent 1. <>. recoiidita. 



Oblique veins as divergent iu basal as in apical half 2. O. lesueiirii. 



1. Oryctaphis eecondita. 

 PL IS, Fig. 14. 



Head and thorax black, abdomen very light. Wings apparently rather 

 more than three times as long as broad, the postcostal stout, and the stigma 

 very elongated. First oblique vein straight and parting from the postcostal 

 at an angle of forty-five degrees ; so also does the second oblique vein, 



