THE IMMATURE STATE OF THE ODONATA. 3 
Oo 
broader than the thorax, and rather rounded behind than tapering. The 
seoments are produced at the sides in modified spines, giving the general 
appearance of the abdomen’s being notched and slightly 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 A’schna in the 
produced and cleft middle third of foreborder. The antenne have two 
joints less than Auschna(?) as far as can be seen. The legs have three- 
jointed tarsi, as in Aischna, but are not equally distant at base, as is the 
case in all known forms of Auschna, while the notched appearance of upper 
edge of femora is wholly peculiar. The processes above front legs are 
Aschna-like, there being no such formation in Gomphina. The form of 
abdomen is more like Gomphus than A%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 Aischna. The entirely closed stigmata are again unlike 
Aischnina. The imago is perhaps still unknown. It may belong to 
Staurophlebia, but is certainly not ASschna or Anax. The large size of 
upper lip would suggest Zonophora among Gomphina, 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 Auschnina and Gomphina, unless in some species of North 
American Aschnina, 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. 
