Nature, ever fertile in her resources, having dispensed with 

 one claw in the anterior feet of the males (at least in the spe- 

 cies of which there were duplicates to examine), — to supply the 

 deficiency, has produced the base of the terminal joint exactly 

 as if a second claw was bent back as in the apterous sex, and 

 soldered to that joint ; it would appear therefore that the means 

 of capturing their prey are curtailed ; but the power to retain 

 it is probably increased. Like the genus Proctotrupes, the 

 abdomens are acuminated, which give them all the appearance 

 of females. 



The following species (with the exception of the first and 

 last) were taken by Mr. Haliday in Downshire near the Bay 

 of Belfast, " on grass in open groves and the adjacent meadows, 

 from the 4th of June to the middle of August. "When in the 

 net they ran with uncommon activity, the chelate ungues re- 

 maining reflected on the tarsus." 



A. Prothorax elongated. 



1. D. formicarius Lat. H. N. 13. 228.— Gen. Crust. 1. 12./ 6. 

 — The female has been taken I believe at Ripley, Surrey, in Aug. 



B. Prothorax short. 1. Legs of nearly equal size. 



2. D. Cursor Brit. Ent. pi. 206. 



3. D. rapax Hal. MSS.—The size of D. Cursor. Black, 

 shining, antennae and legs ferruginous-ochre, the former long 

 and black in the middle, the apex of the posterior thighs as 

 well as of the intermediate and posterior tarsi black ; stigma 

 and nervures ochreous. 



4. jy.Ancidns Hal. MSS. — Smaller than the last; black shi- 

 ning; antennae not longer than the thorax, fuscous except at 

 the base, which is ochreous, as well as the legs, the posterior 

 thighs fuscous at their apex ; nerves of the wings very obscure. 



2. Anterior legs incrassated. 



5. D. crassimanus Hal. MSS. — Like D. rapax, but more 

 robust, the antennae shorter. 



6. D. fulviventris Hal. MSS.~The size of D. lucidus; black, 

 abdomen fuscous-ochre, black at the base, and a dark spot 

 towards the apex ; antennae and legs yellowish piceous, apex 

 of the former ochreous, the posterior thighs dark at their tips, 

 4 posterior tarsi and stigma dirty yellowish white. 



7. D. bicolor Hal. MSS. — Apterous, black, prothorax pale 

 and dirty ochre, anterior margin brown ; antennae at their base 

 and legs pale ochreous fuscous, anterior thighs at their base, 

 middle thighs beneath, a stripe on the anterior tibiae and the 

 apex of the 4 posterior tarsi piceous. Taken in moss on a 

 bank in L-eland, April 1826. 



I cannot conclude without acknowledging my obligations to 

 Mr. Haliday for the handsome manner in which he has al- 

 lowed me to be the medium of communicating his valuable 

 researches, as well as for his liberality in supplying me with 

 specimens to illustrate this remarkable genus. 



Cardtms acaidis (Dwarf Thistle) is figured in the plate. 



