SYNOPSIS OF THE SPECIES DESCRIBED. 



SUB-FAMILY: G-OMPHINA. 



Selys, Monogr. des Gompli., p. 6. 



DIVISION I. INTEGRILABIEES. Selys, Monogr. des Gomph., p. 6. 



The under lip entire in the imago. 



Head cordate ; eyes in the middle of the lateral border of the head ; antennae, 4 articu- 

 lated, 3d flat, dilated, 4th rudimentary ; mask not covering the mouth, nor the upper lip. 

 Legs not equally distant at base ; burrowing legs, at least tlie fore and middle legs ; tarsus 

 2 articulated in the fore and middle legs, 3 articulated in the hind legs, or 2 articulated 

 (Lindenia). Abdomen flattened. 



Legio I. Gomphus. Selys, Monogr. des Gomph., p. 6. 



Mask reaching the fore legs, quadrangular, somewhat longer than broad ; palpus hooked 

 at the tip, inside, or denticulated, or with molar incisions. Hind legs farther distant at base 

 than the fore and middle legs, which are equally distant and fitted for burrowing. Abdo- 

 men lanceolate. 



A. Front border of the mask produced at middle third in a rounded lobe not cleft. 



Sub-genus : HerpetOgomphus. Selys. 1. c, p. G9. (Supposition.) 



1. H. species. Nympha, full grown and larva. Brazil, Rio dos Macacos. 



Mask, breadth half the length, having two small black teeth on each side of middle of the 

 front-border; palpus finely denticul.ited. Abdomen gradually narrowing to tip. Segments 

 2 to 9 with dorsal hooks; lateral spines on 7 to 9 ; segment 10 a little longer than 9; anal 

 appendices as long as segment 10, the superior a little shorter; the lateral ones half as long 

 as the inferiors. 



Sub-genus : G-omphus. Selys, 1. c, p. 118. 



2. G. pilipes (or a related species ; supposition). Selys, 1. c, p. 148. 



Nympha, full-grown female. South Carolina, U. S. Mask nearly square ; end hook 

 of palpus not longer than the denticulations. Abdomen flat. Segments 9 and 10 very con- 

 tracted ; no dorsal hooks ; lateral spines on 8th and 9th segments ; segment 1 half as long as 

 9 ; anal appendices very short, nearly of equal length, the lateral ones a little shorter. 



3. G. viilgatissiinus, Li.vnb. Selys, 1. c. p. 129. 



Nympha, full-grown female and male. Europe. Raised by Dr. F. Brauer. Mask quad- 

 rangular, front-border middle third finely denticulated ; palpus finely denticulated at basal 

 half. Abdomen flat; no dorsal hooks; lateral spines on segments 6 to 9 ; annl appendices a 

 little longer as 10th segment, the lateral ones a little shorter; lateral spines of Uth segment 

 half as long as 10th segment. 



4. G. frateriiiis (or vastus, or fltiviatilis, or aiiiiiicola Walsh, supposition). 



Nympha. Rock Island, 111. Simil.ir to G. viilgafissiiiilis. Segments 8 and 9 with 

 dorsal tubercles; lateral spines of segment 9 longer than segment 10. 



5. G. species. 



Nympha, full grown. Massachusetts. Similar to G. viiig^atissillllis. Spots instead 

 of tubercles on occiput; dorsal hooks but little developed on segments 6 to 9 ; lateral spines 

 on 7 to 9 ; segment 9 longer than 8, with lateral spines half as long as segment 10. 



