124? MANDIBULATA. — COLEOPTERA. 



Hy. caraboides. Linns. — Hy. caraboides. Curtis, iv. pi. 159. Steph. CataL 

 p. 59. No. 598. 



Entirely black or of a glossy violet, sometimes slightly greenish : head with a 

 waved series of punctures on each side, and a deep fovea near the eyes : thorax 

 with scattered punctures on the sides, and two oblique punctate foveae on the 

 disc anteriorly: elytra elongate-convex, with five punctate striae, the two 

 lateral ones somewhat confluent; between the striae are two very obsolete 

 impressed lines : body slightly pubescent beneath ; legs black ; tibiae and 

 tarsi piceous: antennae and palpi ferruginous; the club of the latter black. 



Var. /3. Violaceous-brown, the elytra obsoletely sulcate; legs pale ochraceous. 

 Apparently immature. 



Larva pale ochraceous-brown, with the anterior segments darker ; it has seven 

 fascicles of hair down each side; and the caudal segment has two filiform 

 processes:— the pupaf is slightly hairy anteriorly, and the apex of the abdo- 

 men has a large and powerful bifid process. 



Not uncommon during the greatest part of the year in the ponds 

 and ditches round London, but rare in the north of England. 

 " Bottisham, common. 1 ' — Rev. L. Jenyns. " Whittlesea-mere." — 

 J. C. Dale, Esq. " Earl's Court, in the canal, abundantly." — Mr, 

 G. Waterhouse. " Epping." — Mr. H. Doubleday. 



Genus CII. — Spercheus, Fabricius. 



Maxillary palpi as long again as the labial, the terminal joint elongate-ovate^ 

 attenuated at the base, acute at the apex; labrum transverse-quadrate: man- 

 dibles much bent externally, the apex acute, with acute divaricating teeth : 

 maxilla; with the external lobe palpiform, slender, subulated, the apex setose. 

 Antenna apparently six-jointed, the basal joint longest, conic-cylindric ; the 

 remainder forming a cylindric club: head large: eyes prominent: clypeus 

 emarginate : body ovate, gibbous : sternum simple : tibia angulated, smooth : 

 tarsi with the four basal joints short, the terminal large, obconic ; with two 

 short equal claws. 



The convex body and emarginate clypeus at once distinguish 

 Spercheus from the other Hydrophilidse ; but the more essential 

 characters of the external palpiform lobe of the maxillae, and ap- 

 parently six-jointed antenna?, may be remarked. The species in- 

 habit stagnant waters, adhering to the roots of plants. 



Sp. 1. emarginatus. Supra pedibusque nigricanti-ferrugineis, elytris lineis ele- 



vatis subobsoletis, corpore infra nigricante. (Long. corp. 3— 3^1in.) 

 Sp. emarginatus. Fabricius. — Steph. Catal. p. 59. 2Vo. 599. 



Obscurely glossy-fuscous : head flat, unequal, punctate, dusky-black : eyes black : 

 thorax slightly convex, rugose-punctate, the disc pitchy-brown, the lateral 

 margins pale: scutellum elongate-acuminate: elytra gibbous, coarsely and 



