422 MONOGRAPH OF THE AUSTRALIAN MARSIPOBRAXCH/I, 



The function of the extraoi'clinary pouch with which the mem- 

 bers of this genus are furnished is quite unknown, nor have any 

 observations as yet Ijeen made showing whether its presence is in 

 any way connected with age, sex, or season. 



Geotria australis. 



Geotria australis, Gray, Proc. Zool. Soc. London, 1851, p. 238, 

 pis. iv. f. 3 & v., a7id Catal. Chondropt. p. 142, pis. i. f. 3 ob 

 ii. 1851 ; Giinther, Catal. Fish. viii. p. 508, 1870 ; Hutton, 

 Trans. N.Z. Inst. v. 1872, p. 272, pi. xii. f. 139a (1873) 

 and xxii. 1889, p. 285 (1890); Klunzinger, Sitzb. Ak. 

 Wien, Ixxx. i. 1879, p. 429 (1880); Macleay, Proc. Linn. 

 Soc. N.S. Wales, vi. 1881, p. 384; Sherrin, Handb. N.Z. 

 Fish. p. 56, 1886; Gill, Mem. Nat. Ac. Sc. Washingt. vi. p. 

 110, 1893. 



Geotria allporti, Giinther, Proc. Zool. Soc. London, 1871, p. 

 675, pi. Ixx; Macleay, I.e. p. 385; Johnston, Proc. Roy. Soc. 

 Tas. 1882, p. 141, and 1890, p. 39. 



Wide-mouthed Lamprey. 



Disk elliptical, its length when fully expanded 1^ in its breadth 

 and 1^ to 1§ in the space between its anterior margin and the 

 eye. Eyes conspicuous, the nasal tube opening between their 

 anterior borders. The distance between the extremity' of the 

 snout and the nasal opening is 7i to 8f in the total length, and 

 14 to li in that preceding the first branchial orifice, which is 

 situated much nearer to the last than to the tip of the snout. 

 The space between the last branchial orifice and the extremity 

 of the snout is 3^ to 34 in the total length. Maxillary plate 

 gi'ooved; the inner cusps are lanceolate and strongly keeled; they 

 are entirely distinct from one another, the notch between them 

 being as deep as those which separate them from the lateral 

 cusps, which are much longer and broader, and are divided into 

 two subequal portions by the prolongation of the basal groove; 

 the free edge of the inner portion is strongly compressed, sharp, 



