90 MANDIBULATA. — COLEOPTERA. 



piceus being introduced, the Dy ticus quickly despatched it, although 

 as big again as itself, by seizing it in the only vulnerable part, be- 

 tween the head and thorax. It was very susceptible of atmospheric 

 changes, which it indicated by its movements. 



Sp. 6. submarginatus. Suboblongo-ovatus, nigricans, thoracis limbo elytrorumque 

 margine angustius luteis, sterni laciniis subacutis. (Long. corp. 1 unc. I 

 lin.) 



Dy. submarginatus mihi. Steph. Catal. p. 52. No. 528. 



Closely allied to the preceding, but appears to differ in having the sides of the 

 elytra less dilated, with a narrower luteous margin, and in having the under 

 side very little obscured in the centre of the sternum, and on the abdominal 

 segments ; the laciniae of the sternum appear rather more acute : in other re- 

 spects similar. Female punctulated- above, with the elytra deeply sulcated 

 beyond the middle. 



Probably not sufficiently distinct from Dy. marginalis. 



Taken near London, but sparingly. 



Sp. 7. punctulatus. Undique niger, thoracis elytrorumque margine laterali luteo, 



sterni laciniis rotundatis. (Long. corp. 11 lin. — 1 unc. 2 lin.) 

 Dy. punctulatus. Illiger. Don, xv. pi. 540. Steph. Catal. p. 52. No. 529. 



Black ; head with the labrum and anterior edge luteous, and a rufo-ferruginous 

 lunule on the forehead : thorax above convex, faintly channelled, the lateral 

 margin alone broadly luteous, the anterior sometimes obscurely ferruginous : 

 scutellum with the apex rufescent : elytra scarcely dilated, moderately convex, 

 with the outer magin luteous, and three deeply-impressed punctate stria? on 

 the disc of each : body beneath with a few obscure ferruginous spots on each 

 side ; suture with its laciniae rounded at the apex : legs pitchy-ferruginous. 

 Female finely punctate above, with the elytra deeply sulcated beyond the 

 middle. 



Not so common as Dy. marginalis and circumflexus, though fre- 

 quently taken in ditches and ponds in the neighbourhood of Lon- 

 don, especially in Battersea-fields, during the early summer months. 

 " Very common in Cambridgeshire." — Rev. L. Jenyns. 



Sp. 8. dimidiatus. Niger, subtics testaceus, suturis pectoris nigris, thoracis 

 elytrorumque margine laterali Jlavo, sterni laciniis obtusis. (Long. corp. 1 

 unc. 5 — 6 lin.) 



Dy. dimidiatus. Bergstraesser. Curtis, iii. pi. 99. Steph. Catal. p. 52. No. 

 530. 



Black, shining ; head with the mouth and a broad fascia in front luteous ; and a 

 reddish triangular mark on the forehead : thorax rather sinuated behind, with 

 an obsolete dorsal line, the lateral margins broadly yellow, and the anterior 

 and posterior obsoletely-ferruginous : elytra large, ovate, smooth anteriorly, 



