FOOD OF POST-LARVAL FISH. 439 
LABRUS BERGYLTA Asc. BALLAN WRASSE. 
Thirty-nine specimens were examined which came in the tow-nettings 
from both outside and inside the Breakwater, from June to September, 
and were examined fresh. They measured from 2:5 mm. to 11 mm., the 
small specimens being somewhat contracted so that they naturally were 
longer. The smallest were either empty or contained indistinguishable 
green food remains, those from 4 to 5mm. containing almost entirely 
Copepod nauplii, especially Temora, with occasional remnants of diatoms 
(Navicula) and peridinians, with green food remains. At 6 mm. Copepods 
and Copepod nauplii were taken, one specimen containing the following :— 
10 Cittarocyclis denticulata. 2 Prorocentrum macans. 
1 Temora longicornis. 6 Peridinium sp. 
3 Huterpina acutifrons. 1 Lithomelissa setosa. 
1 Copepod indet. 1 Tintinnopsis berordea. 
The larger specimens contained Copepod remains including Temora 
and Pseudocalanus, and also Podon. Altogether 20 out of the 39 contained 
Copepod nauplii or young copepodid stages, so that evidently this, with 
small planktonic organisms, is their chief food in the post-larval state. 
CARANX TRACHURUS L. Horst MAcKEREL. 
Four specimens of young Horse Mackerel were examined, from inside 
and outside the Breakwater and Cawsand Bay,* in September and October, 
measuring 30 to 40mm. They all contained Crustacea, chiefly Copepods 
including Calanus, Centropages typicus (15 in one specimen), Temora and 
many Harpacticids, including Idya furcata. Crab zoe and Porcellana 
larvee were also present. 
SCOMBER SCOMBER L. MackeErREt. 
Twenty-five Mackerel were examined fresh from the tow-nettings, 
measuring 3 to 16mm., from inside and outside the Breakwater from 
the end of July to the middle of September. The very smallest either 
contained nothing or green food remains, but one of 3-5 mm. contained 
2 Temora nauphi and another a larval gastropod. Nine specimens con- 
tained nothing, the remainder contained green food remains and Cope- 
pod remains which seemed to be almost entirely Zemora nauplii. The 
specimen of 16mm. with remains of Copepods in its alimentary canal 
had in its mouth (swallowed head first) 4 adult Temora longicornis which 
it had probably taken after capture. 
* For a Plan of Plymouth Sound showing where the tow-nettings were taken, sce 
Fig. 7, p. 459. 
