THE niMATUEE STATE OF THE ODONATA. 33 



broader than the thorax, and rather rounded behind than tapering. The 

 segments are produced at the sides in modified sjjines, giving the general 

 appearance of the abdomen's being notched and sliglitly turned up at the 

 edges. The segments have dorsal spines more developed on the third and 

 fourth segments than on the following. Segments of nearly equal length ; 

 ninth longest at sides, and enclosing the tenth, which is much shorter. Ap- 

 pendages short. Middle appendage pyramidal, two thirds as long as infe- 

 riors, blunt. Male projection one half length of middle appendage. Inferiors 

 three-cornered, length somewhat greater than breadth. Lateral superiors 

 less than half as long as middle one, very small, blunt, pyramidal. Genital 

 parts are visible on second and third ventral segments and valves on ninth. 



It is very difficult to place this nympha. The mask is like ^Eschna in the 

 produced and cleft middle third of foreborder. The antenna) have two 

 joints less than iEschna(?) as far as can be seen. The legs have three- 

 jointed tarsi, as in jEschna, but are not equally distant at base, as is the 

 case in all known forms of yEschna, while the notched appearance of upper 

 edge of femora is wholly peculiar. The processes above front legs are 

 J^schna-like, there being no such formation in Gomphina. The form of 

 abdomen is more like Gomphus than ^schna, as are the dorsal hooks ; 

 the sides of abdomen are more like Gomphus and Hagenius, as is also 

 the enclosed tenth segment. The appendages are peculiar, but more like 

 Gomphus than iEschna. The entirely closed stigmata are again unlike 

 ^Eschnina. The imago is perhaps still unknown. It may belong to 

 Staurophlebia, but is certainly not iEschna or Anax. The large size of 

 upper lip would suggest Zonophora among Gomjihina, but Cordulegaster is 

 the only known genus of Gomphina having three-jointed tarsi, and the form 

 of the mask is quite unlike that of Cordulegaster. The marked and peculiar 

 sculpture is unlike iEschnina and Gomphina, unless in some species of North 

 American ^Eschnina, which show a somewhat similar sculpture. Altogether, 

 the nympha is the most peculiar observed. 



A second specimen of this nympha, in the collection of Professor Rosen- 

 hauer, in Erlangen, Bavaria, is stated to be received from Chili. Perhaps the 

 aberrant nympha may belong to a species of the aberrant genus Petalia. 



