HELOPHORUS.—HYDROCHUS. 89 
it is really a Mexican example, and that the occurrence of the species in North America, 
though not hitherto recorded, may be expected. 
2. Helophorus regularis. 
Oblongus, subdepressus, capite thoraceque nigro-sneis, crebrius fortiter rugosis, hoc lateribus subrectis, basin 
versus leviter angustatis, angulis posterioribus obtusis, haud rotundatis; elytris striatis, striis fortiter et 
profunde punctatis, interstitiis equalibus angustis ; antennarum basi, palpis pedibusque testaceis. 
Long. 13, lat. vix 2 lin. 
Hab. Mexico, Guanajuato (Dugeés, coll. Sallé). 
This obscure species is remarkable from the very deep, coarse, and regular punctuation 
of the striz of the elytra. It is closely allied to the European H. wneipennis, Th., but 
is narrower, and the elytra are more deeply striate, with the punctuation denser, more 
regular, and much coarser, and the interstices narrower; their colour is very obscure, 
with faint metallic reflection, and only very faint traces of black marks can be seen. 
According to Leconte’s descriptions of the North-American species, the position of 
H. regularis is apparently between H. linearis and H. lineatus. 
HYDROCHUS. 
Hydrochus, Leach, Zool. Mise. iii. p. 90. 
This is an isolated genus with about thirty named: species. Although none have 
been yet described from South America, still the genus is represented there, as it is also 
in North America ; it has, in fact, a very wide distribution in both eastern and western 
hemispheres. | 
1. Hydrochus debilis. 
Parum elongatus, supra metallescens; antennarum basi, palpis pedibusque testaceis ; prothorace elytris multo 
angustiore, posterius evidenter angustato, inequali, foveolis magnis quinque ; elytris pone medium evidenter 
latioribus, leviter inaequalibus, fortiter punctatis, interstitiis striarum angustis. 
Long. 14, lat. 4 lin. | 
Hab. Guatnmata, Chontales (Janson). 
Head uneven, sparingly punctate. Thorax much narrowed behind, about as long as 
broad, very uneven, the three large discoidal foveee deep and distinct, the two lateral 
less distinct. Elytra rather short, a good deal broader than the thorax, and not parallel, 
becoming a good deal broader behind the middle; of a duller and paler metallic colour 
than the head and thorax. The rows of punctures are deep and coarse, and the inter- 
stices narrow ; the second interstice is elevated for a short distance at the base, and the 
third interstice about the middle; the fourth interstice is slightly elevated just at the 
front of, and again behind, the third interstitial elevation. 
This species, although no doubt closely allied to H. rufipes, Melsh., does not agree 
with Leconte’s description of it or of any of the neighbouring species. _ 
BIOL. CENTR.-AMER., Coleopt., Vol. I. Pt. 2, December 1882. NN 
