xxxiii, '22] ENTOMOLOGICAL NK\YS 265 



the highly modified middle gill that is possessed by all damsel- 

 fly larvae. 



The curiously twisted ventral abdominal gills attached to 

 segments 2 to 7 and bent beneath the abdomen as well as the 

 form of labium and antennae show this nymph to be allied to 

 that of Cora obtained by Dr. Calvert in Costa Rica and de- 

 scribed by him in Entomological News, volume XXII, page 

 52. I place it, therefore, among the Thorinae. Nymphs of 

 three genera of this group Tliorc, l-.nthorc and Cl'.<i!coptcr\.\- 

 remain unknown. The wings of this specimen are badly pre- 

 served so that there is no venation to be seen in them that 

 might help to identify the genus. The wings, however, are 

 long and the nymph though small is apparently grown, and 

 on the basis of size alone I hazard the guess that it belongs to 

 the smallest and most highly specialized genus Chalcoptcrv.v. 

 or else to one of the smallest members of the genus Euihorc. 

 Herewith I publish figures drawn by Dr. Hazel E. Branch 

 and a brief description. 



Fig. i. Nymph of a Thorine damselfly from Peru. To the right, a gill of same detached. 



Length 17 mm., antennae 2 mm., and modified middle gill 4 l / 2 mm. 

 additional. Length of hind femora 4J4 mm., width of head 4^< mm. 



Color all brown, only the sutures and the tarsi paler. On the top of 

 the head are seven oval bare scars that are somewhat yellowish, three 

 of them transversely placed and conjoined about the middle ocellus and 

 two pairs more laterally placed, one at the same level and almost con- 

 tiguous to the eye, and one pair farther back and closer together. 



Head wider than thorax, abruptly narrowed behind the eye with a 

 broadly rounded occipital notch bordered at either side as viewed from 

 above by a rather sharply projecting angle. Antennae 7-jo.nted, the 

 7th joint pale and feebly differentiated, the second joint longest, as long 

 as joints 3 to 7 taken together, and one-half longer than the basal joint 

 and twice as long as the third joint alone. There is a line of flat scale- 

 like hairs bordering the inner margin of this long second joint, and a 

 similar patch on the side of the he-id before the eye, and a dense fringe 

 of scurfy hairs around the front edge of the labrum. The hinge of the 



