June, 1907.] American Species of Papirius. 177 



13. Papiruis opalinus Folsom. 

 1896. Papirius opalinus Folsom. 



Prevailing color, orange-rufous or ferruginous. Head; first 

 two antennal segments, anal tubercle, and legs pale orange-och- 

 raceous. Head with a few short bristles on front, vertex almost 

 naked, swollen dorsally. Antennae shorter than the body, 

 from three fourths to one-half as long according to age ; basal 

 segment twice as long as bi'oad, naked; second three or four times 

 as long, knotty, and hairy toward the epex; third purple, four 

 or five times the basal in length; distal end knotty, and hairy; 

 terminal segment purple, one and a half times as long as basal, 

 lanceolate with whorls of white hairs. Eye spots black, often 

 quadrate. Body, regular, elongate, oval in dorsal outline; an- 

 terior dorsum naked, translucent orange-ochraceous with a broad 

 and median shading of green due to chlorophyll in the stomach ; 

 posterior dorsum and sides orange-rufous to dark ferruginous 

 often with a tinge of maroon ; posterior dorsum with short, white 

 bristles upon minute brown orange - ochraceous spots ; anal tuber- 

 cle hardly visible from above; ventral surface pale yellow, with 

 three pairs of buff, \'ellow tubercles; a small round tubercle on 

 either side of the manubrium ; a large oval oblique one either side 

 of the middle; a narrow oblique pair anterior to these. Legs 

 slender; femur with short, sparse bristles; tibia pale distally, 

 stout spines at moderate intervals. Claws white, very stout; 

 superior claw of almost uniform width, little curved towards the 

 apex, six toothed; inner edge with a tooth at the middle and an- 

 other midway between it and the apex; two pairs of lateral teeth 

 similarly placed near the outer edge; inferior claw two-thirds 

 as long as the other, triangular in shape, tipped with a short 

 bristle, inner edge sinuate or straight with a short bristle one- 

 third from its base. Furcula short, reaching to the ventral tube ; 

 manubrium sparsely hair}-; dentes twice as long, stout, pale or- 

 ange-rufous with short lateral bristles and several longer ven- 

 tral bristles at regular intervals; mucrones white, one-fourth the 

 dentes in length, oblong finely serrated beneath, apex rounded. 

 Ventral sucker pale orange-ochraceous, the tube and filaments 

 together one-fourth as long as the antennae. Length, maximum, 

 1.3 mm. Habitat: reported by Folsom from a green house, 

 Cambridge, Mass. Found in company with P. vittatus. 



The description was taken from a large number of species, 



types of which were placed in the Museum of Comparative 



Zoology. 



Explanation of Plates. 



Plate XI. 



Enlarged drawing of P. iinicolor, showing the insects in their natural 

 environment. 



Plate XII. 



P. unicolor: 1, antennae; 2, claw; 3, eye spot; 4, tenaculunT; 5, 

 ventral sucker and filaments; 6, spring. 



