36 MANDIBULATA. 0RTH01>TF,UA. 



Var. fi. Ac. variegatum. Zetter: O. S 127. — Variegated with ashy^, fuscous, 

 and black; thorax as in var. a; the hinder femora with a whitish fascia on 

 the outer edge. 



Numerous intermediate varieties occur; and I suspect that Ac. nigricans is 

 referrible to this species. 



Frequents nearly the same places as the preceding species, and 

 during the entire summer, appearing towards the end of spring, and 

 continuing till the autumn. 



Sp. 3. nigricans. Corpus subrobustum ; atrum vel fuscum, saspe variegatum, 

 thorace utrinque macula ti'iangulari atra ; alls abbreviatis. (Long. corp. 

 4— 6lin.) 



Ac nigricans. Sowerby B. M. v. i. pi. 74 — Ac. brevipenne. Steph. Catal. 

 303. No. 3346. 



Body somewhat robust ; deep black or dusky, sometimes variegated ; thorax 

 behind slightly exceeding the abdomen in length, with a more or less 

 distinct triangular black spot on each side behind the middle ; wings abbre- 

 viated. 



Almost all the varieties described under Ac. bipunctatum occur in this species, 

 which appears chiefly to differ by having the thorax longer, and the wings 

 shorter and very small. 



Taken at Hertford, Ripley, in Battersea fields, Hants, &c., 

 throughout the summer. 



Family III.— ACHETID.^, Leach. 



Tarsi three-jointed ; antennoE elongate, setaceous ; head large ; crown convex ; 

 eyes ovate; ocelli two or three; thorax truncate in front, and receiving the 

 head, which is inserted nearly to the eyes ; e/_;/if;- a horizontally incumbent, 

 with the sides suddenly deflexed, with an acute ridge at the angle, the disc 

 veined, and dissimilar in the sexes ; body elongate ; breast without laminated 

 appendages ; wings considerably folded longitudinally, and terminating in 

 a kind of subulated tail ; abdomen cylindric, with two exarticulate, setaceous, 

 elongate, villose processes, or styles; legs rather stout, especially the 

 posterior, and their femora ; the hinder tibicB spinose, robust ; tarsi without 

 foot cushions between the claws. 



This is a limited family, and embraces only three indigenous 

 genera, which are no less remarkable from their aspect and habit 

 than from the singularity of their form and manners, as more parti- 

 cularly detailed under their respective genera : from the Locustidse 

 (which have three-jointed tarsi) their elongate setaceous antennae, 



