of some new Exotic Coleoptera. 207 



Male. — The head of the male is nearly equal to the piothorax 

 in length. The eyes are situated at about one-third of the distance 

 from its anterior edge, and behind the eyes it is rather swollen, 

 being again contracted close to the prothorax into a rather narrowed 

 very short neck. The anterior extremity of the head is triangular 

 and deeply excavated, the excavation terminated behind by a 

 slightly curved and raised ridge, at the sides of which, very near 

 the outer base of the mandibles, the antennae are fixed ; which are 

 scarcely longer than the head, with the four terminal joints wider 

 and larger than the intermediate ones. The mandibles are very 

 remarkable in their construction. The right one is about one- 

 fourth of the head in length, slightly curved, and seen laterally 

 almost square, with the end truncate and rather emarginate ; the 

 upper basal angle is produced into a strong obtuse tooth extending 

 backwards over the base of the right antenna. The left mandible 

 is as long as the head, compressed, curved, deflexed at its extre- 

 mity, which is obtuse, angulated on the upper edge with a strong 

 obtuse tooth beyond the middle, and with a deep notch forming a 

 strong tooth on the inside. The maxillae are very minute, formed 

 of a single elongate internally ciliated lobe, narrowed to the tip and 

 angulated at the base, from which arise the small sub-conical and 

 apparently only three-jointed palpi, the terminal joint of which is 

 the smallest, and pointed. I have not been able to determine the 

 form of the mentum, or to discover any traces of the labial palpi. 

 A minute horny piece, emarginate on its inner edge, and with a 

 small bundle of setae in the middle of the outer edge, terminated 

 also by several shorter setag, was observed within the mouth on 

 dissection, and may be the mentum injured by the knife.* The 

 prothorax is about two-thirds of the length of the elytra ; it is 

 highly polished, with a slightly raised ring in front, behind which 

 it is rather constricted, owing to the lateral excavations for the 

 reception of the fore legs, common to the species of Taj)hroderes, 

 as well as to other insects which reside, as these insects doubtless 

 do, in cylindrical burrows in wood. The legs are also very short, 



* The structure of the instrumenta labialia in the BreuthidcE does not appear to 

 have been hitherto determined. Within the mouth of Brenthus Temmlnckn, the 

 largest species of the family, I have observed a small horny piece, dilated and 

 deeply bifid in front, the undersurface of the head being terminated by a deeply 

 emarginate horny plate, which is doubtless the extremity of the jugulum, the 

 small bifid piece being most probably the representation of the mentum destitute 

 of labium and labial palpi. In Arrheiiodes litigiosus. Tie]. (C'olumbia), I have 

 observed a distinct transverse mentum, narrowed at the base, rounded at the lateral 

 angles and emarginate in front ; its inner surface is clothed with fine short hairs, 

 but I have found no trace of labium or labial palpi. 



VOL. v. Y 



