412 MONOGRAPH OF THE AUSTRALIAN MAliSlI'ODRASCIIII, 



begins a space of brilliant green, which extends to the tail; 6ns 

 red, bordered with black." 



Capt. Hutton describes the species as having " a broad band of 

 green down each side of the back, the median line and the whole 

 of the lower surface being pale brownish-white." 



The brilliant green stripe on each side of the back appears, 

 therefore, to be very distinctive of this Lamprey when alive or 

 recently killed as compared with the uniform black or dark 

 brown of the upper surface of Geotria auslralis. 



It will be seen from the synonymy that I have included both 

 of Castelnau's new species as synonyms of Velasia stenostomus, 

 though from the size of the specimens, the insufficiency of the 

 descriptions and the destruction or loss of the type,* it will always 

 be impossible to say whether I am justified in my conclusions or, 

 indeed, to what species his immature and ammoccetal forms 

 should be united. If, however, the types are extant and on 

 examination show that my identification is correct in one or other 

 instance, Castelnau's name must necessarily have priority over 

 mine. 



Yarra singularis. 



The following are the points in Castelnau's description which 

 induce me to believe that his Yarra singularis is founded on an 

 ammocffite of the Narrow-mouthed Lamprey. No generic diagnosis 

 of Yarra was attempted by its author. 



(1). " The body is elongate, being twenty-three times as long as 

 high." 



This character might apply with almost equal force either to 

 this species or to Mordacia mordax; but when these two Lampreys 

 (in the adult state) are laid side by side it will be seen that 

 Velasia is noticeably the more slender of the two. This chai'acter 

 could not possibly apply to Geotria. 



* These types may possibly be in the Paris Museum, where a part at least 

 of Castelnau's collection is said to have gone. 



