222 COMPHUS DILATATUS, VASTUS AND LINEATIFRONS (oDONATA) 
Musee Royal d’Histoire Naturelle, at Brussels, has furnished 
both notes on and drawings from Rambur’s type of dilatafus 
now in that collection. Few specimens from the Southern 
States appear to exist in collections. Mr. R. P. Currie wrote in 
March, 1919, that there were none in the United States National 
Museum; a ‘Scant ” notice in the exchange page of the “Ento- 
mological News” from February to July, 1919, brought forth only 
a single specimen, which came from that untiring helper, 
Mr. W. U. Davis. To all these friends I return hearty thanks 
for th(‘ir assistance. 
Ik'rhaps this paper will attract the atteidion of colk'ctors in 
tlu! South to the desirability of further knowledge of this species 
— our largest representative of the genus Goniphiis. 
On account of the diffei'ences set forth below I propose In re- 
gard the northern form as a distinct species under the name of 
Gomphus lincatifrons now species. 
Black on most parts of tlie body h'ss extcndc'd than in the typ- 
ical southei'ii dilatatui^. The differences which I have found 
are as follows: 
liolh Sc.xx'.s' 
1. Itiiid iiiarf>;iii of the occiput (when tlio head is viewc-d from in front so 
that the top of the irons and the tij) of the verte.x coincide): in dUdliitii.s 
not projecting, or f)ut slightly projecting, above a line drawn from the to]) 
of one eye to the to]) of the other eye; in lincatifrons distinctly ])rojecting 
above the eye to eye line. (See also no. 20 below.) 
2. black on the suture between frons and nasus (])ost cly])(‘us): in dilatatus 
a stri])e or b.a.nd 1.11 to 1.4 mm. wide and eovc'iing half the height of the 
Irons and half the height of th(‘ nasus; in linccdijrons, a line or a narrow st ri])e 
. I I mm. wide at, most, (Livingston cf). 
bhinarium (ant ('-clyi)('us) : in dilataias black (or in ])art, pah' greem, 
'I’ha.xier's cf), this black continued transversely on to ejich side of tlu' nasus 
when- it encloses tla' rhinarium; in linadifrons i)ale green exce])l, for a little 
blackish at the extreme infero-lateral angles, no black on the enclosing sides 
of the nasus. 
4. Labrum in both foiins with t wo transverse marginal black .s|,ri])es, one 
at the base, the otln'r at, the ai)ex; i)ale green area between the.se black stiapes 
occu])ie.s; in dilaUdns on(>-|,hird to one-half (cf), t hre(‘-fifl hs to two-thirds 
(9), ol the total height of t lu' s(4erit('; in iinc(difrons from .(>4 t,o .71 of the 
saitK' height. In s])ecimen.s of both forms there' may be ])re.seid, an i.solated 
ceuttal brownish or blackish spot in the midst of the green, or a ])rolongal ion 
in ( h(' median line' Irom tlu' b;is:il black slri])(' towai’d, or to, the ai)ical stripe. 
r>. Mind prolhoi'acic lobe black: in dilalalns will) no pale s])ol; in lincnli- 
Jrons with a single or double, median, gi'eenish s|)ol,. 
