LIST OF AUSTRALASIAN AND AUSTEOrACIFIC MU BIB AE.— LONGMAN. 25 



Hydromys chrysogaster, Geof . 



1805. — Hydromys chrysogaster, Geof., Ann. Mus. d'Hist. Nat., vol. vi, p. 90. 

 1863. — Hydromys chrysogaster, Gould, Mamm. Austr., iii, pi. xxiv. 

 1887. — Hydromys chrysogaster, Windle (Anatomy), P.Z.S., p. 53. 

 1887. — Hydromys chrysogaster, R. Collett, Zool. Jahr., p. 841. 

 1889. — Hydromys chrysogaster, Thomas, P.Z.S., p. 247, pi. xxix, fig. 7, 

 1892.^ — Hydromys chrysogaster, Ogilby, Cat. Aiistr. Mamm., p. 101. 

 Habitat : Eastern Australia and Tasmania. 



Krefft states ^ that the black snake, Pseudechis porphyriacus, Shaw, is partial to 

 " the young of the water-rat, Hydromys leticogaster . On one occasion sixteen young 

 of this' rodent were taken out of a specimen, so that the reptile must have plundered 

 four nests." The writer's experience is that the adult rats are well able to take care 

 of themselves, being very powerful and vigorous, so much so that a Python variegatus, 

 over ten feet in length, after several attempts to tackle a large Hydromys put in its 

 cage, gave up the contest, being severely bitten. In country districts the water-rat 

 when in its natural surroundings is frequently mistaken by local naturalists for the 

 platypus. It has been pointed out by Windle (loc. cit.) that the two halves of the 

 lower jaw of this rat " are extremel}^ movable upon one another, a quantity of fibrous 

 tissue intervening at the symphysis so as to form a kind of fulcrum by means of 

 which a scissors-like action of the extremely long inferior incisors is obtainable." 



The following subspecies of H. chrysogaster have been described : — - 

 Hydromys chrysogaster fulvolavatus, Gould. 



1863. — Hydromys fulvolavatus, Gould, Mamm. Austr., iii, pi. xxv. 

 1897. — Hydromys chrysogaster fulvolavatus, Collett, P.Z.S., p. 323. 

 1908. — Hydromys fulvolavatus, Thomas and Dollman, P.Z.S., p. 790. 

 Type locality : River Murray, S.A, (Arnhem Land watercourses. — Collett.) 

 Hydromys chrysogaster reginge, Thos. & Doll. 



1908. — Hydromys chrysogaster regince, Thomas and Dollman, P.Z.S., p. 789. 

 1909.- — Hydromys chrysogaster regince, Thomas, Ann. Mag. Nat. His., 8, iv, 

 p. 197. 

 Type locality : Burdekin River, N.Q. 

 Hydromys chrysogaster caurinse, Thomas. 



1909. — Hydromys chrysogaster caurince, Thomas, Ann. Mag. Nat. His., 8, iv, 

 p. 197. 



Type locahty : Parry's Creek, near Wyndham, E. Kimberley, N. W. Austraha. 



Hydromys leucogaster, described at the same time as chrysogaster by Geoffroy 

 St. Hilaire and illustrated by Gould in pi. xxvii of the " Mammals of Austraha," 

 vol. iii, is generally not considered as a distinct species, although Gould states that 

 his specimens from the Hunter and Clarence Rivers were distinguished by their 



8 Krefft, " Snakes of Australia," 1869, p. 46. 



