50 - ADEPHAGA. 
GYRINUS. 
Gyrinus, Geoff. Ins. Par. i. p. 193 (1762) ; Aubé, Spec. Gén. vi. p. 655. 
This is an extensive genus, very widely distributed, and with the species more than 
usually difficult to distinguish by good characters. North America is, perhaps, the 
richest of all countries in species of the genus; but Central America and South 
America seem to be inhabited by only a few species. 
1. Gyrinus turbinator. 
Latiusculus, nitidus, supra nigro-szneus vel chalybeus, margine elevato elytrorum versus apicem rufescente ; 
subtus piceus, plus minusve ferrugineus, epipleuris pedibusque rufis; elytris subtiliter striato-punctatis, 
striis externis parum profundioribus, interstitiis nullomodo elevatis, apicibus truncatis. 
Long. 3, lat. 13 lin. 
Hab. Mexico, Puebla (Sallé); GuaTEMALA, Quiche Mountains 7000 to 9000 feet 
(Champion). 
This is a species allied to the North-American G. ventralis, but of rather broad form, 
and with the wing-cases more truncate and broader behind: the series of punctures are 
fine, but distinct and very regular, the outer a little more deeply impressed than those 
near the suture. The lateral margin near the extremity is rather broadly explanate, 
and is of an obscure red colour; the outer angle of the apex is very broadly rounded, 
the inner angle but little rounded ; the transverse series of punctures fine but distinct. 
Beneath, the margins are red; but the colour of the body appears to vary from a piceous 
red to a clearer red—the two individuals from Mexico being paler than the others. 
The legs are pale red. The male tarsi are broad. In the female the surface of the 
elytra towards the extremity is not so shining as in the other sex, owing to an exces- 
sively minute sculpture. | 
2. Gyrinus obtusus. 
Gyrinus obtusus, Say, Trans. Am. Phil. Soe. iv. p. 447°. 
Hab. Mexico}, Parada and Puebla (Sa//é). 
This species is readily distinguishable by the peculiar structure of the apices of the 
wing-cases ; the side margin at the extremity is expanded and depressed, and the outer 
angle is broadly bent downwards. In some individuals the alternate interstices are 
elevated. It is distributed in collections under the name of Gyrinus plicatus, Sallé ; but 
it appears to me likely to be the species Say described as above. 
3. Gyrinus parcus. | | 
Gyrinus parcus, Say, Tr. Am. Phil. Soc. iv. p.448’; Aubé, Spec. Gén. vi. p. 701. 
Hab. NortH America, Texas.—Mexico!, Orizaba, Cordova, Parada, Jalapa (Sallé) ; 
GUATEMALA, Guatemala city 5000 feet, San Gerdénimo (Champion); Nicaragua, Chon- 
tales (Belt). 
