‘eka PROCEEDINGS OF THE NATIONAL MUSEUM. 145 
ATHERINID. 
Menidia tenuis (Ayres). 
2 J. & G., 80, 29; R. Smith, 80; J. & G., 80a, 456; id., ’81, 43; id., 82, 405; R. Smith, 
( 785, July; HE. & BE. ’89a. 
This species was observed from August to December. Jordan & 
Gilbert procured it in January. We have not seen it during spring and 
summer. It is not frequently brought into the markets. 
Atherinopsis californiensis Girard. (Plate xm.) 
Girard, Pacific R. R. Survey, x, 103, 1859. J. & G., ’80, 29; R. Smith, ’80; J. & 
G., 80a, 456; id., 781, 445 id., 82, 409; R. Smith, ’85, July; Eigenmann, Am. 
Nat., March, 1889. 
During its season this is one of the important food fishes of San 
Diego. It reaches San Diego the latter part of August, although but 
few enter the bay before November. It becomes abundant in October 
and remains so through January. The exact date of its disappearance 
has not been determined; large individuals have been seen as late as 
February 24. Some females are with ripe spawn as early as the begin- 
ning of November and others do not spawn till the middle of February, 
and farther north the spawning season is still later. Ripe females have 
been observed by us at San Pedro in March, and others in the San 
Francisco markets as lateas May. During January and February the 
young of this species occur in enormous numbers along the muddy 
beaches of the bay, and a pail of water dipped at random frequently 
contains a dozen or more of them. 
I have succeeded in artificially fertilizing this species, but have not 
succeeded in hatching the eggs. I have not found the eggs in their 
natural position. The stages reached by the eggs artificially fertilized 
and the larve dredged enable me to give a tolerably complete outline 
of the embryonic and larval stages of this species. 
The eggs and milt of this species were taken from living fish and arti- 
ficially fertilized at 4 p. m., December 31, 1889. 
The zona radiata of this, as in all other species of the Atherinide, is 
provided with long filaments which taper slightly toward the tip; at the 
base they are expanded into a broad hollow disk, a projection of the zona 
fitting into the hollow of the filament. (Pl. x11.) There are about ten of 
these filaments, and they: are scattered evenly over the whole surface of 
the zona. In the green eggs they are closely coiled as parallels of lati- 
tude, being less regularly coiled at the poles. In the ripe eggs they are 
uncoiled, and the green ones can therefore be readily separated. At 
the time the eggs are deposited a large number of globules are scat- 
tered over the yolk; these, however, soon collect in two groups, one at 
the top of the egg and.one at or near the entodermic poles. 
Very frequently the eggs assume such a position that their axes are 
Proc. N. M, 92 10 
