Zool— Vol. I.] CALVERT— ODONATA. 385 



2$ Tepic, Oct., 1894, Eisen and Vaslit. 

 1 $ " Nov., 1894, " 



3^ 



14. Herpetogomphus viperinus Selys. 

 Plate XXV, Figs, i and 5. 



Erpetogomphus viperinus Selys, Comptes Rendus Soc. Ent. Belg., Tome 

 XI, 1868, p. Ixviii; Bull. Acad. Belg., 2d Ser., Tome XXVIII, 1869, 

 p. 176. 



Differ from de Selys' description in having the costa yellow from base to 

 pterostigma, which latter is blackish, although paler at the extremities. The 

 black bands of the thorax in the male are: a submedian on either side of the 

 yellow mid-dorsal carina, not reaching the anterior mesothoracic margin; an 

 antehumeral, of about equal width with the submedian, at its upper end sud- 

 denly narrowed to a line by which it reaches the antealar sinus; and a nar- 

 rower humeral stripe, wider near its upper end. In the female, however, the 

 humeral stripe is absent and the other two are paler in color. 



Male. Superior appendages with the apices curved downwards as is char- 

 acteristic for this species, and a small rounded, inferior, sub-basal tubercle. 

 Anterior hamule apparently similar to that figured for H. crotalinus 1 except 

 that the posterior branch is longer and more nearly equal in length to the 

 anterior branch. Anal triangle of the hind wings four-celled. 



Female. Vulvar lamina cleft in more than its apical half, the interval thus 

 formed between the right and left lobes being almost a right angle with 

 straight sides. The appendages a little longer than 10, probably green in 

 life, the tubercle between them of the same color and as long as 10. Base of 

 the wings as far as the triangle with an ill defined pale brownish yellow cloud. 

 The yellow spot on 7 larger than on the other abdominal segments. 



Male and Female. No basal subcostal cross-veins. Front wings with 

 twelve to fourteen antenodals, first and fifth thicker, nine to eleven postnodals. 

 Hind wings with ten antenodals, first and fifth thicker, nine to ten postnodals. 



Dimensions: Abdomen, S 33 mm., ? 34 mm.; hind wing, <5 26.5 mm., 

 9 28 mm. 



33 3 ? Tepic, Oct., 1894, Eisen and Vaslit. 



Note. — The dimension given for the hind wing of 

 viperinus female by M. de Selys in 1869 (1. c), 37 mm., may 

 be an error, since his original description of 1868, of which 

 that of 1869 is in most respects a copy, gives this as 33, 

 and since the hind wings in Herpetogomphus are usually 

 shorter than the abdomen. 



1 Monog. Gomph., PI. IV, fig. 5/. 



