PHILIP P, CALVERT 
221 
GOMPHUS DILATATUS, VASTUS AND A NEW 
SPECIES, LINEATIFRONS 
(ODONATA) 
BY PHILIP P. CALVERT 
I' xivcrsiti/ of PeiiHsijlnunn, Philoddphia, Pa. 
(\\itli Plates XIV and X\) 
.1 tract 
'I'liis |)a|)er points out tluit two species have been contused under the name 
of Coinphus (lilatalu.'i: tlie true (lilatatn.'i of Ranibur, known only from (Jeorgia 
and Florida, and a form in the northern states for which the name linrafifroas 
is proposed, d’he differentials are listecl and many of them figured, (i. rasliis 
^\'alsh is the northern representative of ililatntus Rambur and its characters 
are biiefly enumerated. A comparison of the existing data on the larvae (jf 
the three forms is given. 
Ill the suHiHier of 1917, tlie late A. Ph Daeeke g;ave me two 
females of a larg'e (roitipbus wliieh he had taken at Weaver, Penn- 
sylvania, a short time before. Tlu'v were, apparently, of the 
spe(‘i('s referred to in recent- literature as (tornphm (lilatatu.s 
Pambur. As this species had not been recorded from Pennsyl- 
vania, if indeed from as far east, I studied them rather minutely. 
It soon became apparent that they differed in a niimlxM- of de- 
tails from the descriptions of the type of the species, wlu'n'fore 
I was led to a more extended study. Hpi'eimens from Floiada 
most closely approached the original of Ivambur. The evidence 
at hand seemed to point to the existence of a typical southern 
form and an atypical northern form. Later in the summer of 
1917, at the Aluseum of ( 'omiiarative Zoology, I studied such 
material as that rich institution possessed. Air. E. B. William- 
son, with his usual liberality, placed his dilaiati at my convim- 
ience. Prof. J. G. Needham lent me two males, one female and 
some larval exuviae from Georgia and Florida. Prof. G. P>. 
Wilson, of Westfield, Alassachusetts, put a female from Tiui- 
nessee at my disposition. Air. Nathan Banks supplied addi- 
tional information on the specimens in the Alusenm at Gam- 
bridge, and, with the return of peace, AI. G. Severin, of the 
TR.\NS. .\AI. ENT. SOC., XLVII. 
