AQUATIC INSECTS IN THE ADIRONDACKS 



477 



Fig. 16 Labium of nympli of Cordulegaster 



formed. I believe that the season for their transformation was past and 

 that the period of adult life for this insect is a long one. The few speci- 

 mens captured were all males. 



Nymph. Measures in total 

 length 41 mm ; abdomen 30 mm ; 

 hind femur 6 mm ; width of 

 head 7 mm, of abdomen 8 mm. 



Body very densely rough 

 hairy; colors (entirely obscured 

 except after molting) yellowish 

 marked with brown spots ; a pair 

 of these at the base of the fore 

 wings, a double submedian row 

 along the dorsum of the abdo- 

 men, oval, with apices con- 

 vergent in each pair: external 

 to these, another row each side 

 with apices divergent ; external 

 to these, a less conspicuous row 

 each side, of spots lying nearer 

 the bases of the segments ; supe- 

 rior and inferior appendages 

 yellow, black tipped, fringed 

 densely on their internal mar- 

 gins with soft black hairs; laterals macuiatus Say, supposition" 

 one fifth as long, not fringed. 



Mentum of labium bell-shaped in outline (fig. 16); median lobe very 

 long and dilated on the cleft apex in a pair of flat ovoid lobes, with ser- 

 rulated margins and each with an external apical denticle ; lateral lobe 

 with 10 or II very unequal sharp teeth on distal margin, the longest of the 

 teeth, the movable hook and the setae of about equal length, the hook 

 several times as thick as the setae; setae five; setae on mentum 10 or 11, 

 six or seven longer ones in a longitudinal row at the sides, and four small 

 ones extending from the proximal end of this row toward the median line. 



Abdomen with segments about equal in length as far as the loth, 

 which is about one third shorter; appendages equal the ninth segment in 

 length ; in the female the long triangular lobes of the ovipositor extend 

 to the apex of the ninth segment, against which they are closely applied ; 

 lateral spines, minute cylindric pointed rudiments, hidden among the 

 hairs of the lateral margins, on the eighth and ninth segments. 



Cordulegaster diastatops Selys 



1854 Tbecaphora diastatops Selys, Acad. Belg. (2) Bui. 21: 101 



1886 Cordulegaster lateralis Scudder, Bost, soc. nat. hist. Proc. 10: 211 



1872 Cordulegaster sayi (nymph) Cabot, Mus. compar. zool. Mem. v. 2, 



art. 5, p. 13, pi. 3, fig. 2 

 1885 Corduleo- aster diastatops (nympli, supposition) Hagen, Am. eut* 



soc. Trans. 12:290 (description) 

 1878 Tbecaphora diastatops Selys, Acad. Bclg. Bui. p. 685 (descrip- 

 tive notes and corrections) 

 1895 Cordulegaster diastatops Calvert, N. Y. cnt. soc. Jour. 3:45 

 (listed from New York state) 



