ATLANTIC FORMS OF SYMPETRUM STRIOLATUM, CHARP. 3 
his sanction to state that our Scottish insect will fall in his 
revision of S. striolatum under the subspecies nigrifemur. 
Just after sending the material to Dr. Ris, Mr. G. G. Black- 
wood, of Edinburgh, brought to me most opportunely a very 
nice little series (four males, one female) of S. striolatum, in very 
mature condition, which he had taken at Mallaig, Inverness- 
shire, on September 4th last; and having found it useful to 
tabulate the principal characters of these and of the more typical 
English form, I give here a reproduction of this tabulation in 
part, along with two diagrams showing the lateral thoracic 
markings, taken respectively from males from Thorney, Cam- 
bridgeshire (Fig. 1) and Mallaig (Fig. 2). 
EneuisH. (Male.) WESTERN ScortisH. (Male.) 
Line at base of the frons ends at the Line extends downwards somewhat, 
eye, without going downwards. as in vulgatum. 
Humeral and second lateral sutures Humeral suture more heavily marked 
very narrowly marked with black. 
The first lateral suture in its upper 
part hardly marked at all (some- 
times, however, the narrow median 
field (F, G) may be lightly outlined 
in fuscous). 
Usually five fairly well-defined yel- 
lowish spots surrounded by black 
on the sides of the thorax above 
the legs. These spots are distri- 
buted thus on 
. | mesinfrepisternum. 
c: mesepimeron. 
D . . 
= metinfrepisternum. 
This field is the metepisternum, 
| and in the typical forms is 
not divided into spots. 
The above spots may be more or less 
confluent; thus a, B may be con- 
fluent or just separated by a narrow 
neck, rarely quite separate; Cc may 
touch E or may be distinctly sepa- 
rate; D may be partially confluent 
with E or narrowly separated. 
Sternum mostly yellowish, the 
sutures sometimes marked with 
blackish. 
with blackish. Narrow middle 
field usually strongly outlined in 
fuscous and divided by a broad 
diagonal line, the two enclosed 
spots (F, G) varying in size, but 
the one nearer the stigma always 
smaller and triangular. 
Note.— Even in an otherwise 
very dark example, the infuscated 
outline of the middle field is slight 
and the diagonal division hardly 
marked. 
Spots A, B, C, D,E variable, but all 
much reduced in size, and in the 
Mallaig examples never confluent. 
Sternum mostly blackish posteriorly, 
with a yellowish oval marking on 
either side of the middle line, these 
markings diverging caudad and 
having a yellowish tail (the black 
condition is no doubt in part the 
result of age), 
B 2 
