32 Memoirs on the Coleoptera 



upper profile from front to elytral tip is almost circular in many 

 cases, and this feature is essentially characteristic of the present 

 tribe, occurring in none other of the subfamily. In addition to 

 these features the prosternum is, as a rule, deeply and abruptly 

 canalate but, although often capable of receiving the beak — always 

 moderate in length and frequently notably short — the sulcus never 

 affords so snug a shelter as in the Coleomerini or Ccelonertini which 

 follow. The femora are subparallel, not spiculate beneath, and are 

 sulcate along their under surface; the tibiae are generally angulate 

 externally near the base. The coloration of the body is deep black 

 to piceo-rufous in whole or in part, but as a most remarkable 

 exception in this respect, a bright green metallic lustre prevails in 

 the genus Bonomius. An exception to the usually rather stout and 

 strongly sculptured beak is seen in Genestus, where this organ is 

 formed as in Balaninus, in a way recalling Costovia of the Optatini; 

 the form of the beak in the two sexes of Matrilia is radically differ- 

 ent, a wholly exceptional character in the tribe. 



The impression or transverse tumidity at the bas? of the abdomen 

 differs from the homologous impression in the Centrinini and some 

 other tribes in being constant in both sexes, as observable also in 

 many parts of the Optatini, and these abdominal characters form 

 valuable taxonomic criteria. Sexual differences are, in fact, very 

 feeble, and in many cases are difficult to discover, generally affecting 

 slightly the relative rostral length and position of antennal insertion. 



Relatively to the prodigious number of species, the genera are 

 not very numerous, those represented in my collection being as 

 follows: 



Tarsal claws straight, connate at base 2 



Tarsal claws free, arcuate 4 



2 — Tarsi subparallel and thick, the second joint transverse, nearly as wide as the 

 third; prosternum as in Diorymerus; pronotum coarsely and closely punc- 

 tured throughout; scutellum very tumid. [Type T. puncHccllis nov.] 



Testalthea 

 Tarsi of the usual form; pronotum never so conspicuously sculptured, generally 



very smooth; scutellum variable 3 



3 — Prosternum deeply and abruptly sulcate, the cavity fully large enough to 

 receive the basal parts of the beak, which is more or less thick, with stout 

 decussate mandibles, the antennal club large, elongate-oval, very compact; 

 abdomen with a laterally well denned and more or less elevated median basal 

 punctate plaque, generally concave and perfectly similar in the sexes; tibiae 

 dentate externally near the base, femora not spiculate, the third tarsal joint 

 well dilated; body large to moderate in size; scutellum variable though 



usually well developed. [Type D. auritus Boh.] Diorymerus 



Prosternum and mandibles as in Diorymerus, the latter strong, moderately bifid 

 and decussate, but rather prominent when closed; antennal club large, 

 evenly elongate-oval, densely pubescent as in Diorymerus and as long as the 

 entire funicle, the sutures distinct, the basal segment a third the mass; 

 abdomen without a differently sculptured basal plaque; middle and pos- 



