420 MONOGRAPH OF THE AUSTRALIAN MARSIPOBRANCHII, 



river is the most widely known, the name itself is so little dis- 

 tinctive that I am inclined to believe that some stream, possibly in 

 Tasmania, where it has/iow been proved beyond question to occur, 

 is intended. 



Type in my possession. 



Total length to 550 millimeters. 



Three specimens have been available to me in the jireparation 

 of this description; for the first I am indebted to the authorities 

 of the British Museum, who, on learning that I was working at 

 the Australian Lampreys, with great kindness sent me one of the 

 New Zealand examples recorded in Dr. Giinther's Catalogue as 

 Geotria chilensis, while a second example from the same Colony was 

 lent to me by Mr. J. P. Hill, only the anterior half of this 

 individual having been preserved; the third was forwarded to me 

 from Tasmania by Mr. Morton and measures 468 millimeters. 



Geotria. 



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



Body rather short and stout, strongly compressed; head large, 

 oblong, with broad, rounded snout ; suctorial disk very large, 

 elliptical, subterminal, extending backwards more than half way 

 to the orbital region, without free external lip, its rim thick and 

 fleshy, and bearing on its inner margin two series of fringed, 

 foliaceous papillfe; the hinder margin of the disk is low and bears 

 a single series of similar but much enlarged papillas; surface of 

 disk smooth. Gular pouch present. Branchial orifices large and 

 slit-like, with a rudimentary valve in front and behind. 

 Maxillary dentition consisting of a single transverse, crescentic, 

 qnadricuspid plate, the basal portion divided from the cusps by 

 a deep groove; outer cusp notched at the extremity; mandibular 

 plate low and crescentic, smooth or feebly cuspidate; disk with an 

 inner series of rather large, diversely shaped teeth, from each of 

 which radiates a series of small, distant teeth; the series are 

 curved obliquely backwards and widely separated; a single trans- 

 verse series behind the mandibular plate, the median teeth the 

 smallest; tongue with a single large plate, smooth on its outer, 



