Haast. — On Clieimarriclitliys fosteri. 103 



Art. XX. — On Clieiraarriclithys fosteri, a Neio Genus belonging to tloe 

 Neiv Zealand Freshwater Fishes. By Julius Haast, Ph.D., F.R.S., 

 Director of the Canterbury Museum. 



Plate XVIII. 

 {Read before the Philosophical Institute of Canterbury, 4th December, 1873.] 

 Amongst a collection of fishes, consisting principally of specimens of Galaxias 

 hrevijnnnis and Retropinna ridtardsonii, obtained by Mrs. J. C. Foster, of 

 Sumnex, during the month of March, in the Otira, where that alpine torrent 

 leaves its picturesque gorge, I observed a few specimens, four to five inches 

 long, which were unknown to me, and on examination were found to be new 

 to science. They proved to belong to a genus hitherto undescribed, forming 

 part of the Trachinina, the second group of the T^xichidce, of which, as far as 

 I am aware, only another genus [Ajihrites) is a freshwater fish inhabiting the 

 rivers of South America and Tasmania, but from which the species under 

 consideration differs materially. 



Genus Cheimarrichthys. 



Body stout ; head spatuliform, broad and depressed, scaleless ; opening of 

 mouth slightly oblique, and with the upper jaw longer ; eyes lateral, somewhat 

 directed upwards ; scales small ctenoid ; villiform teeth in both jaws, and on 

 the vomer. 



Two separate dorsals, the first consisting of three small but strong and 

 sharp spines, of which the third is the largest ; each with a small posterior 

 membrane, so as to prevent the spine from rising to the vertical. Ventrals 

 jugular ; pectoral rays branched. Opening of gills large. 



Operculum and praeoperculum entire ; six branchiostegals ; lateral line 



continuous. 



Cheimarrichthys fosteri. 



D. 3 1 19; Y. 1 I 6; P. 11; A. 14. 



The length of the head is one fifth of the total length (without caudal fin), 

 which is equal to the greatest height of the body. 



Eyes near the upper side of the head ; diameter of eye one fourth of the 

 head ; interorbital space convex, scarcely more than the diameter of the eye. 

 Of the soft but strong dorsal spines, the second is the longest, after which they 

 gradually diminish ; of the anal, the spines rise to the third, which is the 

 longest, both fins being similarly developed. The anal fin begins below the 

 fifth ray of the dorsal, and extends a little further than the former. 



Scales behind the head to the beginning of the soft dorsal, and above the 

 lateral line, very small. 



Colour of head dark olive green, checks paler ; upper portion of body above 



