1863.] 
246 
gives the insect a very different appearance. 4iA. The anterior black¬ 
ish stripe of the pleura is never interrupted or abbreviated, there is a 
distinct posterior blackish stripe on the pleura, and the space between 
the two is pale dull purple or livid instead of greenish yellow, bth. 
The % anal appendages are entirely different, ijth. The hind femur 9 
is not “ anteriorly’’ yellow.—From all other allied species, except gras- 
Knellus Walsh, and quadricolor n. sp. (described below,) consohrinus 
differs in the space between the 1 st and 2 nd pleural stripes being 
livid from grasline.llm the % differs in the abdominal appendages not 
having a large lateral rectangular tooth and the 9 in having a lateral 
thorn to the vertical vesicle. From all allied species, excepting Is^, 
extermi^ Hagen, of which more below, 2nd, intricatus Hagen, which 
is very much smaller and quite different and belongs to a different 
group, and 3rr7, spoUatus Hagen, it differs essentially in the shape of 
the % abdominal appendages. As to spoUatus^ in size and in S abdo¬ 
minal appendages consobrinus closely resembles that species, the 9 of 
which is unknown, but it is separated at once, l.s^, by the median and 
antehumeral stripes of the thorax being very wide apart and not con¬ 
nected by a black band above and below, by the abdominal appen¬ 
dages % not being yellow at base and middle, and 3rf?, by the hind 
femora being i shorter in proportion and much less formidably spined. 
From dilatatus^ externus, vastus and ventricosus n. sp., it differs in the 
tip of the abdomen not being so widely expanded—which in that group 
is caused by the terminal ventral segments being much wider than 
usual. Finally, from adelplius^ dilatatus^ vastus^ vulgatissimm (Eu¬ 
rope), mela&nops (Japan), simillimus (Europe), Lucasii (Africa), pul- 
chellus (Europe), Graslini (Europe), and Jlavipes (Europ.e), it differs 
by the face being immaculate. 
This species singularly resembles externus (Texas) in all its measure¬ 
ments, except that it is at least one-seventeenth larger and the ptero- 
stigma one-sixth longer. It resembles it also in the minutest details 
of its coloration, even down to the % 9 tarsal claws, except that in that 
species the carina of the thoracic dorsum is yellow throughout, the 
* In the exotic subgenus Cyclogomphus the 1st and 2nd pleural stripes are 
described as confluent, and it is stated that this character is not found in any 
other group. {Mon. Qomph. p. 105.) 
