248 The University Science Bulletin. 



ular as to size, shape and spacing and may or may not bear a few small second- 

 ary teeth on the caudal edge; margin of valve between primary teeth notched 

 with small, irregular teeth, especially caudad of apex; tip devoid of teeth; area 

 of ducts conspicuous, granular in appearance, though elongate ducts are visible, 

 circular duct openings visible; open along ventral apical edge (five), at ex- 

 treme apex (one), along dorsal edge of toothed area, and irregularly in the 

 basal area; the two valves of the pair are joined one to the other by a distinct, 

 elongate, slightly curved, heavily chitinized connection present on the dorsal 

 edge, occupying about one-fifth of entire length. 



Aconura argentiolus (Uhler) . 



(PI. XXXI, fig. 9.) 



Length, 1.77 mm.; greatest width, 0.11 mm. About the same width for en- 

 tire length, tapers caudad to apex ; bears no i^reapical prominence ; slightly 

 curved, tip narrowed, rather blunt, obtuse-angled point, chitinization very 

 light; strengthening rod extends caudad to a point between last and next to 

 last dorsal tooth. Toothed area on the dorsal edge occupies a little more than 

 the apical half; teeth twenty-two in number, very small, in the general shape 

 of a greatly flattened obtuse triangle with the caudal edge longer than the 

 cephalic, rather irregular in size, shape and spacing; bear many small, regular 

 secondary teeth along both edges, more numerous on the caudal edge, continu- 

 ous along entire dorsal margin of valve toward apex; tip notched with small 

 regular teeth on both dorsal and ventral edges, not continuous around the tip, 

 teeth on ventral edge slightly larger than those or dorsal ; areas of ducts incon- 

 spicuous; ducts invisible except for apices and circular openings; open along 

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

 irregularly in the basal portion of the valve. 



N'ephotettix cvrtipennis (Gillette and Baker). 



(PI. XXXI, fig. 10.) 



Length, 2.5 mm.; greatest width, 0.25 mm. Apical toothed half slightly 

 wider than basal portion, tapers caudad to apex; bears an indistinct, broadly 

 rounded preapical prominence on ventral edge; only slightly curved, tip nar- 

 rowed, ends in obtuse-angled point, chitinization moderately heavy; strength- 

 ening rod extends caudad beyond last distinct primary tooth. Toothed area 

 on dorsal edge occupies the apical half; teeth twenty-four to twenty-five in 

 number, of medium size, in the general shape of a very flat, obtuse triangle 

 with the caudal side longer than the cephalic, fairly regular in size, shape and 

 spacing; bear small, regular, secondary teeth on both edges, continuous around 

 the apex of each tooth, seven to fifteen on caudal edge and one to four on 

 cephalic edge; tip notched with small teeth on both dorsal and ventral edges, 

 not continuous around the tip, about 55 on ventral edge, area of ducts con- 

 spicuous, granular in appearance though elongate ducts are visible, open along 

 ventral apical edge (five), at extreme apex (one), along dorsal edge of toothed 

 area, and a few in the basal region; the two valves of the pair are joined one 

 to the other by an elongate, narrow, heavily chitinized connection extending 

 the entire length on the basal area. 



