Mr. A. White on a new species of Longicorn Beetle. 109 



they have been for a short or long time out of the pupa state ; 

 they always keep to the ground and walk slowly. Amongst 

 the Prionidce this group, containing Dorysthenes, CyrtognathuSy 

 Cacoscelis, and perhaps Acanthinoderus, Psalidognathus and Prio- 

 nacalus, resembles in habit Dorcadion and allied genera among 

 LamiadcB, as Guerin-Meneville very justly remarks (/. c. Mag. de 

 Zool., and Kev. Zool. Cuv. 1840, p. 39 Cyrtognathus) . I may 

 here add, that the curiously curved jaws and very strong legs with 

 their slender elongated tarsi seem to fit them particularly for 

 getting into the ground, escaping from it and walking on its 

 surface*. 



In a small collection of insects from Mexico, purchased last 

 year by Mr. Gray for the British Museum from M. Hartweg, 

 there are three specimens of a subgenus of Prionidce, at first 

 sight with very considerable resemblance to the Psalidognathus 

 modestus, Fries, Vetensk. Akad. Handl. 1833, p. 327. t. 9. f. 3, 

 agreeing with that species in many particulars, but to me appear- 

 ing distinct. 



From the genus Psalidognathus of Mr. George Gray (Griff. A. 

 K., Insects, ii. p. 115. t. 6. f. 14), as characterized both by Mr. 

 Gray and M. Fries, it differs in many particulars, sufficient, if 

 the established subgenera of PrionidcB be valid, to constitute a 

 new subgenus closely allied to Psalidognathus : in my description 

 any comparisons refer to this latter genus. 



Prionus, subg. Prionacalus, White. 



c?. Head behind the eyes without a prominent spine; the la- 

 teral margin behind produced into a slight process directed back- 

 wards. 



? . Head midway between the eyes and the posterior edge, 

 with a strong broad spine on each side. 



(^ $ . Cheeks where jaws are inserted, without strong tooth on 

 the outside. (See PI. VIII. fig. 1 b.) Labium very short (in Psa- 

 lidognathus the labium is elongated). 



Jaws very strong (in female widest), with the upper surface 

 rounded, the ends bent downwards, the edges strongly toothed 

 and notched, the terminal tooth fitting into a groove in the other, 

 and the ends probably lapping over each other. 



Palpi very prominent (PI. VIII. fig. 1 « c and 2ab). Maxillary 

 with terminal joint largest, securiform and much dilated, penul- 

 timate joint much shorter than the third. Labial palpi with the 

 terminal joint much dilated. Antenna 11- jointed, with first joint 



* The Euchroa dinndiata of Gvierin- Menevilln, Delesseit, Voyage, p. 57. 

 1. 14. f. 1, and Mag. de Zool., is the iWr<e«s/rico/or of Newman,' Mag. Nat. 

 Hist. iv. 191 ; the original spociuiens, from Mv. Children's collection, are iix 

 the British Museum. 



