234 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



2. Geotria australis Gray. 



(Plate XXX, Figs. 3 and 3«.) 



Geotria australis Gray, Proc. Zool. See. 1851, 238; id. List Spec. Fish 

 Brit. Mus. 142, pi. ii ; 1851 (Inkarpinki River); Giinther, Cat. Fish. 

 Brit. Mus. VIII, 508, 1870; Plate, Zool. Jahrb. Suppl. V. 668, 1902 

 (Valdivia, Chili; King George's sound, Australia). 

 Habitat: Australia and Chili. 



No specimens of this species were obtained by Hatcher. The follow- 

 ing is a description based on the type specimen. 



"Skin of the throat very lax, forming a large pouch; maxillary lamina 

 thin, crescent-shaped, with four sharp teeth, the middle pair of which are 

 only half as broad as the outer. Mandibulary lamina very low, slightly 

 sinuous ; suctorial teeth in numerous series, rather distant from one 

 another, aniscuspid ; only those nearest to the mouth somewhat larger, 

 the others small ; only one transverse series of very small teeth between 

 the mandibular lamina and the posterior lip, which is beset with numer- 

 ous broad, leaf-like fringes, as in the remainder of the margins of the 

 disk; suctorial disk subtriangular with the lateral lobes very broad; first 

 and second dorsal fins rather widely separated from each other." Giinther. 



2. EXOMEGAS Gill. 



Exomegas Gill, Proc. U. S. Nat. Mus., V, 524, 1882 [macrostomus). 



Type : Petromyson niacrostoniits Burmeister. 



Giinther (Cat. Fish. Brit. Mus. VIII, 505, 1870) was the first to recog- 

 nize the aberrant nature of this genus. He says : " The following species 

 would appear to be the type of a distinct genus, but it will be better to 

 leave its creation to an ichthyologist who will be able to characterize it 

 from an autopsy of examples." The genus was named by Gill, /. c. It 

 is not improbable that it is synonymous with Geotria. Smitt says on this 

 point: 



"Cette structure de la ventouse et de la bouche, comparee aux descrip- 

 tions et aux figures des Geotria et des Velasia chez les auteurs, ne nous 

 donne aucun signe de divergence de forme mais bien de developpement. 

 C'est un plus-ou-moins du developpement des cartilages et de la sub- 

 stance cornee du meme type. Si Ton place les esp^ces decrites dans 



