376 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3 d Ser. 



3. Lestes tenuatus Rambur. 

 Plate XXV, Fig. 3. 



Lestes tenuata Ramb., Ins. Nevr., 1842, p. 245; Selys in Sagra Hist. Cuba, 

 Ins., 1857, p. 463; Bull. Acad. Belg., 2d Ser., Tome XIII, 1862, p. 315; 

 Hagen, Syn. Neur. N. Am., 1861, p. 69; Proc. Bost. Soc. Nat. Hist., Vol. 

 XI, 1867, p. 289. 



Lestes tenuatus Kirby, Cat. Odon., 1890, p. 162. 



As these are probably fresher specimens than those pre- 

 viously available for description, the following is given: 



Male (young). Pale ochre-brown except where different colors are ex- 

 pressly stated, viz.: labrum perhaps light blue in some in life; between each 

 antenna and the adjoining eye a nearly semicircular, dark metallic green spot ; 

 vertex blackish or dark metallic green; on either side of the thoracic dorsum 

 a narrow, well denned green stripe extending from the anterior mesothoracic 

 margin almost to the antealar sinus, its width slightly greater than the dis- 

 tance separating its inner (mesal) margin from the mid-dorsal thoracic 

 carina; a very ill defined and much paler metallic green stripe on the mese- 

 pimeron; between these two (ante- and posthumeral) stripes, and a consider- 

 able part of the sides of the thorax, probably pale blue in life, with the pectus 

 and the sutures yellowish; a small dark brown spot near the anterior end of 

 the latero-ventral metathoracic carina; abdominal segments yellow under- 

 neath, 1-8 or 10 with a pale metallic green reflection above, but paler, when 

 present, on 9 and 10; a narrow, transverse, pale yellow basal ring on 3-7 or 

 8; an ill defined, transverse, apical fuscous band on 3-8. 



Superior appendages as long as 9, forcipate, yellowish at base, sometimes 

 fuscous at tip, outer, upper edge with seven to eight acute denticles, inner, 

 lower margin with a fairly stout basal tooth which is truncated in a straight 

 line parallel with the outer edge of the appendage; beyond this tooth the 

 inner margin of the appendage viewed from above is somewhat dilated and 

 bears a row of acute, slender denticles, terminating at a constriction of the 

 appendage about one-sixth of its length before the apex; viewed from the 

 side the basal tooth has an obtuse conical form, the terminal third of the 

 appendage is directed slightly downwards, the dilatation of the inner margin 

 and subsequent constriction are not visible and the extreme apex is blunt. 



Inferior appendages 1 half as long as the superiors, reaching beyond the 



1 In the Transactions of the Amer. Ent. Soc, Vol. XX, 1893, pp. 198, 199, I pointed out 

 that the " inferior appendages " of the males of the Zygoptera and Anisoptera are not 

 homologous, and briefly described their development, and that of the superior append- 

 ages, from the structures of the nymph. These statements have been confirmed by the 

 recent valuable and important researches of Heymons ( Anhang Abhand. Konigl. preuss. 

 Akad. Wiss. Berlin, 1896) from the embryological standpoint. His remarks (1. c, p. 43) 

 suggest the inappropriateness of employing the same name for structures which (mor- 

 phologically, although not physiologically) " nichts mit einander zu thun haben." 

 (Compare figs. 3 and 5, PI. XXV, accompanying the present paper.) I have not adopted 

 his terms, however, since one of them at least (appendix dorsalis for the " inferior 

 appendage " of Anisopterous males) is anatomically inappropriate when applied to the 

 imago, although quite fitting in the nymph. I have continued, therefore, to use the 

 old terms of the systematists. Perhaps it will be best to select names for these various 

 " processes " and "appendages " which shall, by their etymology, indicate the segments 

 to which they belong, rather than their positions as dorsal, lateral, superior, inferior. 



