228 The University Science Bulletin. 



on the dorsal edge, and tliirteen small teeth on the ventral and apical edges; 

 the three large teeth at the apex of the shorter valve bear small secondary 

 teeth; the ducts are conspicuous, few in number, all located at the apex, six 

 to seven openings visible. 



Oncopsis distinctus (Van Duzee). 



(PI. XXVI, fig. 3.) 



Length, 1.5 mm.; greatest width, 0.08 mm. Long, narrow, rodlike, about 

 the same width for entire length; the two valves of the pair are not identical, 

 but differ in length, shape of tip, and teeth found at tip; slightly curved, 

 narrow at apex to obtuse point, heavily chitinized; strengthening rod ex- 

 tends caudad as far as the second dorsal tooth. Toothed area on dorsal edge 

 occupies only the apical portion of the valve; the longer valve bears two large, 

 heavily chitinized teeth on the dorsal edge and fourteen small, inconspicuous 

 teeth on the ventral edge, and the shorter valve bears two large, heavily 

 chitinized teeth on the dorsal edge and fourteen small, inconspicuous teeth 

 on its ventral and apical edges; none of the teeth bear secondary teeth; the 

 ducts are conspicuous, elongate, few in number; five to six open apically, 

 and others are scattered along the basal rod of the valve and open dorsally. 



Genus Bythoscopus Germar. 

 The, ovipositors of two species of this genus have been examined 

 and found to be simiUar. They are about the same width for the 

 entire length; slightly though distinctly curved, narrow abrutly near 

 the apex, and end in a rounded extreme apex. The teeth on the 

 dorsal edge occupy about a third of the apical length, are numerous, 

 small, irregular, and bear no secondary teeth. There are teeth on 

 the ventral edge of tip in both species. The ducts are conspicuous, 

 elongate, rather few in number. In both species there is present on 

 the dorsal edge about midway of the valve an elongate, distinct, 

 heavily chitinized connection between the two valves of the pair. 



Bythoscopus apicalis (Osborn and Ball). 



(PI. XXV, fig. 10.) 



Length, 1.53 mm.; greatest width, 0.14 mm. The apical portion is slightly 

 wider than the basal portion, distinctly curved; the valve narrows from a 

 point about six-sevenths of its entire length to the tip, extreme apex rounded, 

 chitinization moderately heavy; strengthening rod extends caudad to within 

 six dorsal teeth from the apex. Toothed area on the dorsal edge occupies a 

 little more than the apical third of the length; teeth numerous, very small 

 and inconspicuous, flatly rounded, irregular in shape and size, unevenly 

 spaced; bear no secondary teeth; the ventral edge of the tip bears a few in- 

 conspicuous teeth; ducts conspicuous, comparatively few in number, one group 

 opens apically, and another group along the basal rod of the valve about mid- 

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

 elongate, chitinized connection present on the dorsal edge about midway of 

 the valve, this connection bearing an angular tooth near its caudal extremity. 



