INVESTIGATIONS IN THE COLUMBIA RIVER BASIN. 
193 
One of tbe most characteristic marks of this species is the presence of two or three mem- 
hranons stays coimecting the iuiier ventral rays with the skin of the l)ody, thus forming pockets 
under the \'entral lins and liolding them down quite firmly. Adults show an extraordinary 
development of the nuptial tuhercles, which are present on top of head, and on back and sides of 
body. On the body a single tubercle is located ou the middle of the free edge of each scale, being 
I'ormed by a thickening of the integument. Ou the belly, this thickening involves the entire 
surface of the scales, giving to this region a mosaic-like appearance. Beneath this thickened 
epidermis the scales are often partially absorbed, especially on the breast. Tubercles are 
also present on the inner (superior) surfaces of the pectoral fins, where they follow the fin rays 
in single series, branching to correspond with the forking of the ray. 
We find the origin of the dorsal liu in this species constantly behind the front insertion of the 
ventrals. It varies from midway between base of median caudal rays and nostrils (its usual 
position) to a pmint midway between caudal and posterior margin of pupil. The variation 
includes the position of the dorsal assigned as a distinguishing feature in Agosia slmsu'ap 
Eigenmaun, this being the only character assigned as distinguishing sli inswap from falcata.* 
Table showing rariaiion in sjjecies of Agosia. 
Locality. 
Head iu length. 
p 
j Eye in bead. 
Snout ill bead. 
0 tf. 
liFii 
1+0 
Teeth. 
1 
Dorsal fin. 1 
1 « 
•X. 
3 
3 q 
P 
Scales. 
o - 
fct— 
u q; 
^ %. 
tn 
S o 
C y 
c o 
“ O 
Cl 
'E 
i| 
. 
Agosia nuhila. 
4 
3|-4 
4 
3 
0 
1,4^4. 1 
8 
52 57 
10 
G 
Falls. 
Little Spokane River, 
4 
4 -4^ 
44-5 
■ 
3 
0 ' 
2, 4-4, 2 
8 or 9 
To preoiiercle. 
52-03 
62 
77 
9 
Dart’s Mill. 
Hangman Cr.,Tekoa . . 
31-4 
4 -4 | 
4J 
+ in 1 
1, 4-4, 2 
8 or 9 
Beyond pre- 
51-65 
57 
50 
10 
0 
2. 4-4, 2 
opercle. 
1, 4 4, 2 
G4 70 
CG 
44 
9 
+ in 10 
pupil. 
9 
9 
ton. 
Poise R., Caldwell 
4 
U 
+ 
1,4-4, 1 
8 
To eye 
7 
50 
56 
1 
1 
Potlatcli Cr., Lewistou . 
3I-4J 
4 -4r 
24-3 
0 
1 , 4 - 4, 0 
8 or 9 
To preox>erclo. 
7 
CO-06 
62 
10 
10 
1,4-4, 1 
2, 4-4, 2 
4 4i 
4 ih 
U 5 
22-3 
-J- 
8 or 9 
60-64 
62 
13 
9 
IV alia Walla R., Wat 
3^-4 
4 “ 
4“-44 
22-3 
40 
39 
15 
lula. 
-j- 
52 61 
20 
20 
2, 4-4, 2 
48 58 
52 
3 
4 
4i 
34-4 
22-3 
-f 
.. . 
7 
-j- 
Yakima. 
' 
halis. 
4 
41-4J 
32-4 
2^-3^ 
50-57 
6 
(> 
Cbehalis. 
A. mibila carringtonii. 
Port Neut Kiver, Po- 
4 
44 
3| 
3| 
0 
1, 4-4, 4 
8 
To eye 
7 
09 
09 
1 
1 
oat('Ho. 
-j- 
53 72 
64 
15 
13 
4i 
4-^ 
4 
3 
-f 
9 
1 
1 
-1- 
61 67 
64 
4 
4 
catello. 
4^ 
41 
4 
3 
4- 
9 
Y 
62 03 
62i 
0 
o 
3| 
4^ 
4 
3 
-j- 
63 79 
71 
48 
10 
4^ 
5 " 
4 a 
H 
44 
4J-5 
-1- 
y 
64 
0 
6 
A. falcata. 
Boise Liver, Caldwell. 
32-4 
4i-5^ 
34-4 
2|-3 
+ 
9 or 10 
53 59 
97 
11 
Payette R., Payette. .. 
3|-4 
4-^-5 
3 
27 
6 
ColunibiaR., Umatilla. 
4|-5 
34 - 4 “ 
2J-3 
+ 
1,4-4, 1 
9 or 10 
To nostril 
7 
52-58 
56 
55 
8 
jL. Umatilla. 
Columbian., Umatilla. 
3i-4 
4J-5 
4 
24 
+ 
1,4-4, 1 
8 or 9 
To front of 
7 
63-70 
66 
10 
10 
]uipil. 
Payette R., Payette . . . 
33 
4^5 
4J-5 
2i-3 
+ 
1, 4-4, 1 
S or 9 
60-65 
63 
6 
6 
* Eigenmaun, American Naturalist, February, 1893,154. 
F. C. P,. 1894 13 
