98 Mr. J. O. Westwood’s Descriptions. 
Genus. Megadeuterus, IVestw. 
Since the publication of my Monograph upon the Paussidce, I 
have had an opportunity of examining and delineating the insect 
therein mentioned, as contained in the collection of the late A. H. 
Haworth, Esq. under the name of Cerocomci marginata , but which 
I regarded as a second species of the genus Megadeuterus. 
The type of this genus, Paussus Jtavicornis, is evidently very 
nearly allied to the genus Malachius, and the insect above men- 
tioned is also to be regarded as possessing the same affinity. 
In addition to the curious structure of the 2nd joint of the 
antennae, the Megad. Haworthii is distinguished by two inter- 
esting peculiarities ; the anterior tarsi are only 4-jointed, whilst 
the four posterior tarsi are 5-jointed, and the antennae are only 
10-jointed. In this latter respect, indeed, this insect nearly 
approaches several beetles ordinarily placed in the genus Mala- 
chius , such as M. Mmaculalus, &c. from North America, New 
Holland, & c., but in the former respect I know of no Coleopterous 
insect which exhibits a similar character. 
Megadeuterus Haworthii, Westw. Plate X. fig. 9. 
Caeruleus ; labro, antennarum articulis 2 basalibus fulvis, margine 
toto thoracis, elytrorum sutura lateribusque rufis. 
Long. corp. lin. 2f. 
Habitat ? 
In Mus. Hopei, olim Museo Haworthii. 
Caput porrectum, caerulum, punctatum, pubescens ; antice lineis 
nonnullis impressum. Labrum magnum, semirotundatum, 
fulvum. Mandibulae dentatae. Palpi cylindrici, parvi, labiales 
brevissimi. Antennae 10-articulatae ; lmo articulo crasso, 
2do maximo, subquadrato, convexo, supra et postice excava- 
tione magna, cujus latera utrinque in dentem obtusum pro- 
ducuntur ; articulis reliquis nigris, minoribus, serratis, ultimo 
ovali. Thorax angulis anticis acutis, posticis vero rotundatis ; 
disco nigro, margine omni rufo. Scutellum parvum, rotun- 
datum. Elytra oblongo-ovata, subdepressa, thorace latiora, 
caerulea, punctata, pubescentia, sutura marginibusque rufis ; 
rufescentia paullo ante medium elytrorum nonnihil dilatatd. 
Pedes nigri, geniculis tarsisque rufescentibus. 
Date X. fig. 9, Megadeuterus Haworthii magnified. 9a. The head from above. 
9b. The head from beneath. 9c. The three basal joints of the antenna. 
9 d. The fore leg. 9e. The posterior leg. 
