1869.| DR. MACDONALD ON A NEW GENUS OF MUGILID&. 39 
side, the left apparently overlapping the right. Dorsal fins two, 
distinct, the anterior consisting of four rigid spines, and the posterior 
of eight soft rays and one rigid in front. Pectoral fins small and 
scaly to the tip. Abdominal fins with five soft rays, fronted by one 
spinous. Anal with ten rays, the first alone of which is spinous. 
No lateral line visible as in the Mullets generally. Scales large, 
both the longitudinal and transverse measurements reaching 5, of 
an inch, with a mucus-groove on the inner surface of each, fulfilling 
the office restricted to those that form the lateral line in other fishes. 
On reviewing Dr. Giinther’s Synopsis of the characters of the three 
genera of Mugilidee, viz. Mugil, Agonostoma, and Myzus, I find that 
fka loa is not strictly conformable to any of them, but apparently takes 
up an intermediate place between Agonostoma and Myxus. Thus the 
cleft of the mouth extends on the side of the snout to the orbit as in 
Agonostoma, dissociating it from Myzus ; the teeth of the upper jaw, 
however, are in a single series, the anterior margin of the lower 
jaw is sharp, as in Myzus, and the upper lip is notched to receive 
the mesial prolongation of the lower, still further distinguishing it 
from Agonostoma. I therefore conceive that Ida loa deserves a 
place in a new genus, for which I propose the name of Gonostomyzcus, 
retaining the native word, Joa loa (black), for the species. The fol- 
lowing diagnosis of the genera of Mugilidz may be given to illus- 
trate the view here expressed, adopting Dr. Giinther’s characters :— 
I. Cleft of the mouth extending on the sides of the snout, but 
not to the orbit. 
a Nowrue teeth im the JAWS © Js...0..0dttes one en sees oees ese Mugil. 
6. Small teeth in a single series in the upper jaw, and 
sometimes in the lower and on the palate. Anterior 
margin of the mandible sharp ...............400..-.0:05- Myxus. 
II. Cleft of the mouth extending on the sides of the snout, beyond, 
to, or nearly to, the orbit. 
a. Small teeth in a single series in the upper jaw, in two 
lateral crescentic clusters in the lower jaw, and in 
a short irregular transverse row on either side of the 
yomer. Anterior margin of the mandible sharp ... Gonostomycus. 
6. Small teeth at least in one of the jaws, and sometimes 
on the palate. The lower lip with the margin 
rounded not shar pil Mne-cevus »: atten eveseeoes sabes Agonostoma. 
Of course the further discovery of species referable to Gonosto- 
myxus may suggest some modification of the characters above given. 
I shall now give a brief description of Z/a-loa-fishing on the Wai 
Manu. 
The Maroons of Jamaica capture the freshwater Mullet with a 
pronged spear, pursuing it under water; but the Feejeeans take the 
Ika loa very skilfully in a small net, assisted by outlying divers who 
decoy the fish into the net, cutting off their escape. The men of 
Soloira, under the Vuni Chief of Vun Mbua, are famous for their 
knowledge of the habits of the ‘‘ Black Mullet”’ and their success 
in fishing for it. 
It will be necessary here to give an idea of the construction of the 
net. It is very simple, consisting merely of a piece of net once 
