250 The University Science Bulletin. 



Euscelis exitiosus (Uhler). 



(PI. XXIII, fig. 11; pi. XXXI, fig. 1.) 



Length, 2 mm.; greatest width, 0.2 mm. Apical portion, which occupies 

 two-thirds of length, is slightly wider than basal portion, tapers caudad to 

 apex; bears a distinct, angled, preapical prominence on ventral edge; only 

 slightly curved beyond curved basal attachment, rather abruptly narrowed at 

 tip, ends in sharp point, chitinization moderately heavy; strengthening rod ex- 

 tends caudad as far as last doreal tooth. Toothed area on dorsal edge occupies 

 apical two-thirds of length; teeth thirty-four to thirty-five in number, rather 

 small, of a general triangular shape, with the caudal edge longer than the 

 cephalic and the apex rounded, fairly regular in size, shape and spacing; bear 

 small secondary teeth on both edges, not continuous around the apex of each 

 tooth, eight to eighteen on caudal edge, two to four on cephalic edge; tip 

 notched with small, regular teeth on both dorsal and ventral edges, practically 

 continuous around the tip, about eighty on ventral edge between preapical 

 prominence and extreme apex; area of ducts conspicuous, granular in appear- 

 ance; open along ventral apical edge, along the dorsal edge of the toothed 

 area, one in each tooth, and a very few in the basal area; the two valves of 

 the pair are joined one to the other by a poorly defined connection which is 

 slightly more heavily chitinized than the rest of the basal area, upon whose 

 dorsal edge it is located. 



Euscelis striolus (Fallen). 



(PI. XXIII, fig. 12; PL XXXI, fig. 2.) 



Length, LI mm.; greatest width, 0.16 mm. Apical portion occupying two- 

 thirds of length but little wider than basal portion, narrows caudad to tip; 

 bears no preapical prominence; only slightly cuiwed, tip abruptly narrowed, 

 ends in obtuse-angled point, chitinization moderately heavy; strengthening 

 rod extends caudad as far as second dorsal tooth from apex. Toothed area on 

 dorsal edge occupies apical two-thirds; teeth eleven to twelve in number, 

 rather large, of a general triangular shape with the apices broadly rounded, 

 fairly regular in size and shape, irregular in spacing; bear secondary teeth of 

 various sizes and shapes on both edges, three to nine on caudal edge and one 

 to four on cephalic edge; general arrangement of secondary teeth is very ir- 

 regular; tip bears a few irregular teeth on the dorsal edge only, there is a 

 slight irregularity of the margin on the ventral apical edge; area of ducts con- 

 spicuous, granular in appearance, circular duct openings easily visible; open 

 along ventral apical edge, in extreme apex, along dorsal edge of toothed area, 

 and in basal region where many elongate ducts are visible; the two valves of 

 the pair are joined one to the other by an elongate, distinct, chitinized con- 

 nection present on the dorsal edge of the basal area. 



Euscelis anthracinus (Van Duzee). 



(PL XXXI, fig. 3.) 



Length, L4 mm.; greatest width, 0.18 mm. About the same width for en- 

 tire length beyond curved basal connection; preapical prominence wanting; 

 slightly curved, tip narrowed by broadly rounded ventral edge, extreme apex 

 bluntly rounded, cliitinization rather heavy; strengthening rod extends caudad 

 as far as last dorsal tooth. Toothed area on dorsal edge occupies apical half; 



