390 SEEEICOENIA. 



Candeze (A. hilaris and its allies being excluded), and with these I am compelled to 

 associate three out of the four members of his genus Monelasmus *, the differences 

 becoming evanescent in the new species here described. Physorhinus galapagoensis, 

 Cand. (nee Waterh.), also probably belongs to it. In Monelasmus augusti and 

 M. moratus (and no doubt in M. Jamaica? also), as in some of the new species here 

 described, the frontal margin or carina is obliterated in the middle, but the front is in 

 all cases raised above the anterior margin of the head and separated from it by a 

 narrow space. The species here referred to Anchastus agree in the following parti- 

 culars : — Front separated from the anterior margin of the head by a rounded or sub- 

 angular ridge, which is sometimes obliterated in the middle ; the sutures between 

 the prosternum and propleuree narrowly separated, channelled or not in front ; posterior 

 coxal plates abruptly and subquadrangularly widened inwards, in some species acutely 

 triangularly dilated near the middle ; third tarsal joint rather broadly lamellate beneath, 

 the fourth joint small. The third joint of the antennae is usually as large as the 

 fourth, but in some of the species it is not longer than the second. 



'I he channelling of the prosternal sutures (a character used to separate Mater 

 from Megapenthes) varies according to the species. Monelasmus is placed by 

 Candeze in his ' Ludiites '; but in Ludius and its allies the front is not separated from 

 the anterior margin of the head, and the third tarsal joint is simple. With three 

 exceptions, the whole of the Central-American species are brightly coloured, many of 

 them having the thorax or elytra maculated. All appear to be rare. The genus, 

 which is very widely distributed, includes some of the most interesting Elateridee of 

 our region. The Central-American representatives may be grouped by their structural 

 characters thus : — 



a. Hind angles of the prothorax obliquely unicarinate; elytra separately 



rounded at the apex « coxal plates broadly widened inwards, and mode- 

 rately wide outwards. 

 a'. Antennae with the third and fourth joints equal; prosternal sutures 

 not or feebly channelled in front. 



a!'. Front completely margined Species 1-4. 



b 1 '. Front incompletely margined Species 5-10. 



b'. Antennas, with the third joint a little shorter than the fourth; pro- 

 sternal sutures channelled in front ; front completely margined . . . Species 11. 



b. Hind angles of the prothorax longitudinally unicarinate; antennas with 



the third joint a little shorter than the fourth; front incompletely mar- 

 gined; prosternal sutures channelled in front; elytra conjointly rounded 

 at the apex ; coxal plates moderately widened inwards, becoming very 

 narrow outwards .... 



Species 12. 



* The name Monelasmus can perhaps be retained for M. guyanensis, Cand., that insect having the head 

 differently formed :— The antennal cavities are large and deep, and limited internally by an oblique ridge, 

 which extends upwards and nearly meets the margined, subangular, prominent frontal plate. 



