152 REV. 0. P. CAMBRIDGE ON THE GENUS IDIOPs. [Mar. 10, 
sence of the pseudobranchize cannot be retained among the family 
characters, and is limited to the former genus. Prototroctes stands in 
the same relation to Haplochiton as Coregonus does to Salmo; and 
however the Haplochitonide may differ from the Salmonide in the 
structure of the jaws and intestinal tract, it is a most remarkable 
fact that the fresh waters of the southern hemisphere are inhabited 
by two genera with adipose fins, so extremely similar in outward ap- 
pearance to the northern Salmonoids. 
The species from Southern Australia is called Prototroctes marena, 
and distinguished by having about eighty transverse series of scales 
along the body. The second species, from New Zealand, is very 
closely allied to it, but more elongate and having smaller scales. 
D. 12. A. 19. Transverse series of scales 100. The height of the 
body is nearly one-fifth of the total length (without caudal); the 
head is as small as in the other species, its length being contained 
six and a half times in the total (without caudal) ; the same uniform 
coloration as in Coregonus. For this species I propose the name of 
Prototroctes oxyrhynchus. 
The fish were sent with the denomination ‘‘ Mountain-Trout ;” 
therefore it appears that they inhabit the fresh waters of the moun- 
tainous interior of New Zealand. The stomach and intestines were 
crammed full of a clayey mud, which may have been taken in on 
account of nutritive matter contained in it, or which may be the 
remnants of worms which had fed on mud. 
7. Supplementary Notice on the Genus Jdieps. 
By the Rev. O. P. CamBrince. 
(Plate VIII.) 
Since writing the communication upon the genus Idiops read at 
the Society’s Meeting on the 10th ult.*, I have discovered, in the 
collection of Arachnida at the British Museum, three additional unde- 
scribed species—one from the same locality as that from which Idiops 
sigillatus was received (Swan River, Australia), the two others from 
Africa (one from its eastern the other from its southern portion) 
The distribution of this genus thus appears to be exceedingly wide, 
comprising Syria, different parts of South Ameriea, Africa, and 
Australia. 
The following are the descriptions that I have been enabled to 
make of these additional species :— 
Iprops MEADII, n sp. (Plate VIII. fig. 4.) 
Male adult: length 10 lines; length ‘of cephalothorex 6 lines, 
breadth of ditto 43 lines. 
The whole of this Spider, except the abdomen, is of a deep and 
somewhat bistre-brown colour. The cephalothorax is of a broad 
* See anted, p. LOL. 
