229 



by their having preserved their horny coverings. It has no trace 

 of the gutteral pouch, and so I believe that this is accidental, or 

 rather belongs to a particular state of some specimens, perhaps to 

 the old individuals of one sex. The only dental difference between 

 Geotria and Mordax seems to be the presence in the latter of the 

 two groups of three long teeth in the maxillary. Nothing shows 

 better the remarkable knowledge that Dr. Grunther possesses of 

 fish than his not having taken the extraordinary gular sac as a 

 generic character ; but I cannot consider the specimens which 

 do not possess it to be young, as the length of the one I have 

 described here is a little more considerable than that of the 

 type in the British Museum (twenty inches). 



In the list of the Chondropterygii of the British Museum it is 

 said that the type, which was given to that institution by Mr. 

 Pain, was from a river InTcar Pinki, in South Australia, but 

 there must be some confusion, as that gentleman tells me that 

 he picked it up on the Brighton beach, Hob son's Bay. 



MORDACIA. 



Formed by Gray on a Lamprey from Tasmania, which has 

 appeared to Dr. Grunther to be similar to one from Chili. There 

 is no doubt that the two belong to the same genus, but it is 

 very improbable that they should be specifically similar. 



MORDACIA MORDAX. 



Petromyzon Mordax, Richard, Log. Git., p. 62, pi. 38, fig. 3. 

 Mordacia Mordax, Gray, Chondropterygii of the Brit. Mus., 

 p. 142 



Guntlier, Catal., vol. viii., p. 508. 



(The Lamprey?) 

 The mouth is elleptical ; the lateral lobes not broad nor fringed ; 

 mandibulary lamina not visible externally, but bearing seven to 

 nine acute conical cusps, which, when the horny coverings fall, 

 have the appearance of tubercles. On the maxillary is, on each 

 side, a group of three conical, acute teeth, directed backwards, 

 and placed one in front and two behind ; suctatorial teeth form- 

 ing a circle round the lips ; they are small, and number at least 

 twenty ; behind them is a series of much larger ones, very broad 

 at their base, and very acute ; in front, three of them are dis- 

 posed in a triangle ; the othei s emit a sort of transverse ridge 



