Monotoma.] CLAVICORNIA. 271 



Ceylon, &c. ; they are small, elongate insects, as a rule dull with sca- 

 brous sculpture, and may further be recognized by their more or less 

 quadrate thorax, of which the anterior angles are more or less callose or 

 prominent ; there are nine British species, which are all very distinct, 

 but the differences are in many cases comparative, and hard to express in 

 words ; they are very slow in their movements, and occur for the most 

 part in vegetable refuse, hot-beds, &c. ; two of them, however, are found 

 exclusively in ants' nests. 



I. Upper surface more or less coarsely scabrous. 



i. Colour, at least of head and thorax, more or less 

 pitchy-black or pitchy-brown. 



1. Head oblong, not much narrowed before eyes, 

 which are small ; habitat in ants' nests. ( Gy- 



rocecis, Thorns.) 



A. Thorax much longer than broad .... M. CONTCICOLLIS, Aube. 



B. Thorax not much longer than broad . . . M. FOBMICETORUJJ, Thorns. 



2. Head triangular, much narrowed in front of 

 eyes, which are larger ; habitat in vegetable 



refuse, &c. (Monotoma, 5. sp.) 



A. Sculpture of upper surface very coarse ; 

 thorax considerably narrowed in front; elytra 

 short, almost ovate ; impressions on forehead 



not marked M. SPINICOLLIS, Aube. 



B. Sculpture of upper surface coarse ; thorax 

 quadrate with sides straight and parallel ; 

 elytra longer and more parallel ; impressions 



on forehead not marked M. BREVICOLLIS, Aube. 



C. Sculpture of upper surface coarse or mode- 

 rately coarse; thorax subquadrate with sides 

 slightly but evidently contracted in front ; 

 elytra variable, elongate-ovate ; impressions 



on forehead very strongly marked .... M. PICIPES, Serbst. 



D. Sculpture of upper surface moderate; 

 thorax subquadrate with sides straight and 

 parallel ; elytra elongate, parallel, scarcely 

 wider than thorax; impressions on fore- 

 head absent M. QTJADEICOLLIS, Aub6. 



ii. Colour rufous ; form parallel ; thorax quadrate 

 with sides parallel ; forehead with strong im- 

 pressions M. ETJFA, Eedt. 



II. Head and thorax finely scabrous, elytra scarcely 



scabrous ; head oblong, colour rufous M. sr/B-4-FOVEOiiATA, Wat. 



III. Upper surface shining, not scabrous ; form small 



and linear ; colour dark M. LONGICOLLIS, Qyll. 



JUL. conicicollis, Aube (angusticollis, auct. ; Gyrocecis angusticollis , 

 Thorns.). Elongate, dull pitchy-brown or fuscous, upper surface, espe- 

 cially of head and thorax, very scabrous ; head large, elongate, sub- 

 oblong, with forehead not foveolate, eyes small ; antennae ferruginous ; 

 thorax much longer than broad, narrowed in front, conical, with the 

 anterior angles projecting in a lobe, and the sides strongly serrate, with 

 two distinct foveae towards base ; elytra with rugose strine, and with the 



