FOOD OF POST-LARVAL FISH. 459 
CLUPEA SPRATTUS L. 
164 specimens were examined fresh from the tow-nettings, from both 
inside and outside the Breakwater, from January to May and from July 
to November, the bulk from January to April, measuring 3 to 27 mm. 
Those from 3 to 4 mm. have no eye pigment, a large yolk sac and no food. 
From 4:5 mm. the eye is pigmented and, although yolk may still be 
PLYMOUTH 
eae: 
D4. 
Qc. 
WEST 
p BREAKWATER 
Fic. 7.—Plan of Plymouth Sound. BB=Batten Bay. CB-=Cawsand Bay. DI= 
Drake’s Island. DR=Duke’s Rocks. J B=Jennycliff Bay. K=Knap Buoy. 
NG=New Grounds. QG-=Queen’s Grounds. P-=Panther Buoy. P P =Penlee 
Point. R R=Reny Rocks. W P=White Patch. 
present, green food remains occur and also in the larger specimens. A 
spherical body which may be Halosphera was present in one. From 
4-5 mm. and upwards the yolk sac disappears, but green food remains are 
still present, probably from diatoms, as 6 Thalassiothrix nitzschiordes were 
present in one of 5mm. Not until July, in a specimen of 8 mm., is any 
crustacean food present, and this specimen contained 2 Temora nauplii 
