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. 



^ , long. Corp. 30 millim. ; ? , 47-50 milim. 



Head and prothorax of about equal length j mesotliorax 

 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. Antennas 

 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 tlie extremity of each segment and diminish- 

 ing in size hind wards. 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 carina3 dentated, also the tibias slightly 

 in the female, especially at the base ; all the coxas spined at 

 the base (at least in the female), those on the hind coxa3 the 

 largest. First joint of tarsi as long as the remainder ; first 

 joint of antennas long, broad, and compressed. 



Male with the cerci small, pincer-like; female with tlie 

 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 Uttle-knoum Species of LibelluliuEe 

 frovi Jamaica in the Dublin Museum of Science and Art. 

 By W. F. KiRBY, F.E.S., 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. Schartf, of examining some of the Odonata, among which 

 I found several species of extreme interest, which form the 

 subject of the present paper. 



