178 MANDIBULATA. COLEOPTERA. 



of other evident characters, as the dissimilarity in the proportions 

 of the terminal joints of the maxillary palpi, the cornuted head, un- 

 equal thorax, subhemispheric body, &c. 



Sp. 1. mobilicornis. Castaneo-niger, subtus testaceus : mas, thorace quadri- 

 dentato, capitis cornu recurvo mobili. (Long. corp. 4 lin.) 



Sc. mobilicornis. Fabricius.—Bo. mobilicornis. Stepk. Catal. 106. No. 1101. 

 Curtis, vi. pi. 259 ? 



Black, sometimes with a chestnut hue, beneath testaceous ; clypeus sinuated, 

 punctate, with a long linear, slightly recurved, moveable horn in the middle : 

 thorax deeply punctate, with a groove in the middle, having an acute process 

 on each side, to receive the occipital horn, and two longer, more or less 

 elongate, compressed, bent, processes on each side near the anterior angles : 

 elytra deeply punctate- striated: body beneath testaceous; legs castaneous: 

 palpi and antennas flavescent, the club of the latter pitchy-chestnut. Female 

 with obsolete rudiments of tubercles on the head and thorax. 



Variable in colour, as well as in the length of the occipital horn, but rarely en- 

 tirely testaceous. 



Not common : found in various places within the metropolitan 

 district ; specimens having been found at Hertford, Darenth, 

 Birch- wood, Dartford, &c. : it has also occurred in Cambridgeshire 

 at Wisbeach, on Moushold heath, near Norwich. " Coombe-wood." 

 — Mr. Hatchett. " A single female in Lord Clifford's park near 

 Bristol." — G. Waring, Esq. 



Sp. 2. testaceus. Mufo-testaceus, oculis nigris: mas, capitis cornu brevi ar- 

 cuato, thorace quadrituberculato : fcemina, capite bituberculato. (Long. corp. 

 3— 3i lin.) 



Sc. testaceus. Fabricius. — Bo. testaceus. Sieph. Catal. 106. No. 1102. 



Less than the last; rufo-testaceous ; eyes black: male with a rather short, 

 slightly recurved acute horn on the clypeus : thorax punctate, with a shallow 

 central channel anteriorly, having a minute prominence on each side, and a 

 large tubercle of a triangular form near the anterior angles : elytra punctate- 

 striated. Female with two minute tubercles on the clypeus. 



Smaller than the last, with the horn on the clypeus more slender, shorter, less 

 recurved and tapering to its extremity, the armature on the thorax very 

 short, and sometimes nearly obsolete : the eyes black, and the serrations of 

 the anterior tibia? piceous. 



I am induced to consider this distinct, from the facts that out of an extensive 

 series that I possess of each species, there are no intermediate specimens ; 

 the armature of the head and thorax being in all remarkably short, and the 

 tubercles on the thorax very small, and in some instances obsolete, while all 

 the specimens arc considerably smaller than those of Bo. mobilicornis ; and 



