42 ADEPHAGA. 
RHANTUS. 
Rhantus, Lacord. Faun. Ent. Par. i. p. 309 (1835) ; Sharp, Trans. Roy. Dubl. Soc. n.s. ii. p. 899. 
Colymbetes (ex parte), Aubé, Spec. Gén. vi. p. 218. 
This is a rather extensive genus of about forty species, widely distributed on the 
surface of the globe, but more especially characteristic of Europe and North America. 
It is doubtful whether any of the Central-American species will ultimately prove to be 
peculiar to the region. 
1. Rhantus suffusus. | 
Rhantus suffusus, Sharp, Trans. Roy. Dubl. Soc. n. s. 11. p. 6138. 
Hab. Mexico, city of Mexico (Flohr), Toluca (Sal/é). 
The male of this species remains unknown, only a single female, extant in Sallé’s 
collection, being known in addition to the individual found by Mr. Flohr. 
2. Rhantus binotatus. 
Colymbetes binotatus, Harris, New Eng. Farm. vii. p. 164; Sharp, Trans. Roy. Dubl. Soe. n. s. ii. 
p. 614. 
Colymbetes maculicollis, Aubé, Spec. Gén. vi. p. 245. 
? Colymbetes gutticollis, Say, Trans. Am. Phil. Soc. iv. 1834, p. 442. 
Hab. Wustern Unitep Stares.—Mexico, Oaxaca, Almolonga, Jalapa, Toluca, Parada 
(Sallé), Guanajuato (Dugés, coll. Sallé); Guaremata, San Gerdénimo (Champion) ; 
Costa Rica, Cache, Irazu, 6000 to 7000 feet, San Francisco, 4500 feet (Rogers). 
In some of the Mexican individuals of this plentiful species the black spots on the 
elytra become condensed and suffused, so as to render the wing-cases blackish. Some 
of these specimens approach very closely to R. mexicanus, so that I have little doubt 
that species will prove to be an extreme form of &. binotatus. 
3. Rhantus mexicanus. 
Colymbetes mexicanus, Cast. Et. Ent. p. 101; Sharp, Trans. Roy. Dubl. Soc. n. s. ii. p. 614. 
Hab. Mexico, Oaxaca, Parada, Toluca (Sad/é), San Luis Potosi (Palmer); GuaTEMaLa, 
San Gerdnimo (Champion). 
4. Rhantus atricolor. (Tab. I. fig. 11.) 
Colymbetes atricolor, Aubé, Spec. Gén. vi. p. 265; Sharp, Trans. Roy. Dubl. Soc. n.s. ii. p. 615. 
Hab. Mexico, Guanajuato (Dugés, coll. Sallé), Orizaba (Sallé), Alvarez mountains 
(Dr. Palmer). 
5. Rhantus calidus. 
Dytiscus calidus, Fabr. Ent. Syst. i. p. 198. 
Colymbetes calidus, Aubé, Spec. Gén. vi. p. 262. 
