142 LIST OF FISH. 



Petromyzon planeri, var. Cuv. Reg. An. ii. 118. 



Hab. — Europe, Seine. 



A very doubtful species; Cuvier says it is the same as the 

 former. 



4. Lampetra Lamottenii. American Lainpern. 



Petromyzon Lamottenii, Lesueur, Hist. N. A. De Kay, Nat. Hist- 

 of New York, 382, pi. 79, f. 249 (mouth), pt. 1. Zool. 1842. 



Hab. — N. America, New York. 



a. ?In spirits. North America. From the Paris Museum. P. 

 fluviatilis, Mus. Paris. 



3. GEOTRIA. 



Upper internal tooth large, transverse, crescent-like, divided into 

 four lobes ; the two inner lobes small, acute ; outer truncated. The 

 lower internal tooth transverse, narrow, slightly sinuous. The la- 

 bial teeth numerous, far apart, conical, acute, in arched series, 

 diverging from the throat ; the innermost one larger, rest small ; the 

 innermost one of the lower part on each side, small, elongate, trans- 

 verse, with two small, rudimentary tubercles. Tongue with two 

 elongate, conical, arched teeth, with a triangular plate on the lower 

 side of the base. Throat with a very large dilatable pouch, t. 1, f. 3. 

 Dorsal-fins two, far apart. Mouth very large, surrounded with 

 rather large, transverse, torn leaves. 



This genus chiefly differs from Velasia in the rudimentary state of 

 the lower internal tooth, and in the form of the labial teeth, and in 

 the large size of the oral disk, and the extraordinary development of 

 the throat-pouch, which is found in a rudimentary state in the 

 Petromyzon marinus This development of the pouch, is perhaps 

 to adapt the animal to the long drought of the Australian rivers. 



1. Geotria australis. Pouched Lamprey. Tab. 2. 



Geotriaaustralis, Gray, Proc. Zool. Soc. 1851. 



Hab. — South Australia. Fresh-water. 



a. In spirits. Kiver Inkar pinki, South Australia. Presented by 

 R. A. Pain, Esq. 



