ODONATA OF BAJA CALIFORNIA. 519 



(greenish?) run vertically from the upper to the lower 

 surface of the eye (lig. 62). The fourth abdominal seg- 

 ment cannot be said to be carinate at all (cf. Kirby /. c). 

 The pterostigma of the teneral male is pale-colored for 

 its entire length; in the adult males it is black for its en- 

 tire length, as shown in Kirby's figure; in the females 

 and in one adult male, it has the "exterior half white 

 surrounded with fuscous," as described by Hagen. Con- 

 siderable variation exists in the extent of the wing mark- 

 ings of the females. 



Front wings with the sectors of the arculus varying 

 from a condition in which they are separated from their 

 origin to that in which they arise by a common stalk 

 whose length may exceed that of the lower piece of the 

 arculus ; discoidal triangle crossed by one vein in both 

 wings of 28 individuals, by two veins in both wings of 20 

 individuals; 18 individuals have one cross-vein on one 

 wing, two on the other; 2 have three and one, 2 have 

 three and two, i has the triangle free on both wings; one 

 supratriangular in both wings of 7 individuals, in one 

 wing only of 18 individuals, absent in the others; highest 

 number of antecubitals 12, of postcubitals 7. 



Hind wings with the discoidal triangle crossed by usu- 

 ally one, or in some cases two, cross-veins; one supra- 

 triangular present in both wings of 18 individuals, in one 

 wing only of 21 individuals, absent in the remainder. 

 One ? has the triangle altered to a quadrilateral on both 

 hind wings. 



The third joint of the penis is relatively long as com- 

 pared with Orthcmis fe7'rtLginea, LibeUtda satm'tita, etc., 

 and becomes wider to the apex, which is without the two 

 chitinous threads to be found in species of other genera. 

 Anterior lamina projecting but little, its margin entire. 

 Genital hamule the most prominent, its apical half bifid, 



