114 RHYNCHOPHORA. 
TESSEROCERUS. 
Tesserocerus, Saunders, Trans. Ent. Soc. Lond. 1. p. 155 (1836); Chapuis, Mon. Plat. p. 288. 
Damicerus, Spinola, MSS.; Dejean, Cat. ed. 3, p. 333 (1837). 
The genus Tesserocerus is confined to Tropical America, whence fifteen species, of 
which three are Central American, have been described. Another species, 7’. linearis, is 
known from a single example taken in Spain, whither, no doubt, it had been accidently 
imported. The species are easily distinguished from those of the genus Platypus by 
the obliquely inclined front of the head, which is less sharply separated from the vertex, 
and by the absence of any emargination to the sides of the prothorax, the surface of 
which is longitudinally strigose in parts, and sometimes covered with scanty long hairs. 
More important, but less easily recognized, characters reside in the mouth-parts; the 
maxillary palpi are corneous and cylindrical in Tesserocerus, membranous and flattened 
in Platypus. 
Chapuis has grouped the species into three divisions :—I. Tesserocert genuini, 
which, curiously enough, does not contain the type of the genus, 7’. insignis, Saund.; 
Il. Tesseroceri clavati for the latter species and T. spinolw; III. Tesseroceri tortiles 
for T. inermis, Guér. | 
This arrangement is unnatural. The third division is more remote from the other 
two than they are from each other, differing as these do only by the greater or less 
production of the scape in the females. Now T. belti, Sharp, has in this character 
precisely the same relation to 7. inermis as have the species of Division II. to those of 
Division I. It is better, therefore, to amalgamate the two latter and to retain two 
divisions only instead of the four which are otherwise necessary. 
The development of the antennal scape is no doubt an adaptive modification connected 
with the boring habits of the female; it is correlated with the size of the species, and 
its taxonomic value is limited to that of furnishing specific characters. 
Five species are known as yet from our Region. 
1. Elytra with the apical margin not explanate . . 2 - 1 ee ee ee 
Elytra with the apical margin strongly explanate. . . . . . » « - « belli, Sharp. 
2. Postero-lateral angles of the elytra produced (males) . . . . . . «+ 3. 
Postero-lateral angles not produced (females). . . . . . 6. 
3. Apical margin of the elytra with a tooth between the process and the suture . spinole, Chap. 
Apical margin with no tooth internal to the process. ©. 2 2. 6 6 1 ee & 
4. Base of the third interstice granulate . . . . 6. ee ee ee ee 
Base of the third interstice not granulate; elytral spines long, acute, 
incurved . eee ee we we . . .  « Spinax, sp. 2. 
5. Apical spine of the first interstice not reaching so far back as the lateral 
process . 6 ee 6 6 ee ew see . dejeani, Chap. 
Apical spine of the first interstice reaching as far back as the lateral 
process 6 ee ee ee ee eee eo ertciUs, SP. DL 
