DIDELPHYS.—CHIRONECTES, 201 
specimens which he dissected. He adds that it burrows in the earth, and suspends 
itself by the tail to the branches of trees, feeding partly on fruit, as do several of its 
congeners *, 
2. CHIRONECTES. 
Chironectes, Illiger, Prod. Syst. Mamm. p. 76 (1811). 
One species of the Didelphide is so far modified for an aquatic life that its claim to 
generic distinction has been almost universally recognized. Still the distinctive characters 
of Chironectes are not of fundamental consequence, the most important being :—the 
complete webbing of the hind feet, which are proportionally very large; and the great 
development of the pisiform bone of the carpus, which causes a tubercle on the outer 
side of the fore foot, resembling a rudimentary sixth digit. In the female the pouch is 
well developed. 
The only known species of Chironectes is a small animal of handsome markings, 
its ground-colour of clear grey being varied by large confluent patches of velvety black 
on the head and back. It attains a length of about twelve inches, with a tail of from 
thirteen to fifteen inches. 
1. Chironectes variegatust. 
Lutra minima, Zimmermann, Geogr. Gesch. ii. p. 8317 (1780, ex Buffon)'. 
Lutra saricovienna, Shaw, Gen. Zool. i. pt. 2, p. 447 (1800, ex Buffon)’. 
Chironectes variegatus, Illiger, Abh. Ak. Berlin, 1811, p. 107 (descr. orig.)’; Frantzius, Arch. f. 
Naturg. xxxv. 1, p. 318°; Sclater, P. Z.S. 1871, p. 702°. 
Tlacuazin de agua of Guatemalans. 
Zorro de agua of Costa-Ricans’*. 
Hab. GuateMata (Salvin), Coban (Sarg); Costa Rica (Frantziust)—Sourn AMERICA 
to Brazil. 
First described from Guiana}, the Yapock or Water-Opossum has a pretty extensive 
range, being found in suitable localities in the northern parts of Brazil, Guiana 1, and 
* Monogr. de Mamm. i. p. 51. 
t I have retained Illiger’s well-known specific name*, instead of reviving either of the forgotten 
titles previously bestowed by Zimmermann’ and Shaw”, for the following reasons. There can be no doubt 
that Zimmermann’s Lutra minima was intended for the present species, it being founded on Ja petite Loutre de 
Guayane of Buffon (Hist. Nat. Suppl. iii. p. 157, pl. xxii.); but the name minima when applied to the only 
known member of a genus is so misleading as to come fairly under Rule XI. of the Stricklandian code. Lutra 
saricovienna of Shaw is compounded of the above-named petite Loutre de Guayane and la Saricovienne of Buffon 
(Hist. Nat. xiii. p. 319), which is identified by Buffon himself with the Carigueibeju of Marcgrave (Hist. Nat. 
Bras. p. 234), the Lutra brasiliensis of Brisson and of modern zoologists. Shaw’s title may therefore be at once 
dismissed, and L[lliger’s name retained as the earliest which can be satisfactorily used for the present 
species, 
BIOL. CENT.-AMER., Mamm. Vol. 1, Octoder 1881. 2D 
