from the Louisiade Archipelago. 231 
The complicated spines of this insect are very difficult to 
describe. It is not very similar to any previously described 
species with which I am acquainted. 
Promachus insularis, sp. n. 
3, long. corp. 30 millim.; ¢, 47-50 milim. 
Head and prothorax of about equal length; mesothorax 
about three times as long as broad and narrower than the 
metathorax, which is rather longer than broad; abdomen 
with the first six segments transverse, broader than long; the 
terminal segments narrower, raised and carinated. Antenne 
a little longer than the head and thorax. Colour brown, 
slightly inclining to red in the male. Spines arranged as 
follows :—Median line: head with a pair of spines at the 
back; prothorax with two pairs; mesothorax with three 
pairs; metathorax with two single spines ; and abdomen with 
a single spine at the extremity of each segment and diminish- 
ing in size hindwards. Lateral spines: mesothorax with 
four on each side; metathorax with one on each side; female 
with a row of spines on each side of the abdomen, 
Femora with all the carinz dentated, also the tibie slightly 
in the female, especially at the base; all the cox spined at 
the base (at least in the female), those on the hind coxe the 
largest. First joint of tarsi as long as the remainder; first 
joint of antenne long, broad, and compressed. 
Male with the cerci small, pincer-like; female with the 
upper spine extending for one third of its length beyond the 
operculum. 
Hab. Sudest Island, Oct. 10, 1888. 
Allied to Acanthoderus (?) hystrix, Kaup. 
XXVI.— On some new or little-known Species of Libellulinz 
— from Jamaica in the Dublin Museum of Science and Art. 
By W. F. Krrpy, F.E.S8., Assistant in Zoological Depart- 
ment, British Museum (Natural History). 
THE Dublin Museum of Science and Art contains a valuable 
series of insects of all orders from Jamaica, and I have lately 
had the opportunity, through the courtesy of the Keeper, 
Dr. Scharff, of examining some of the Odonata, among which 
I found several species of extreme interest, which form the 
subject of the present paper. 
