The eggs of Gobius minutus and Gobius microps are already known, Petersen (1892, 1917) having distinguished between them and figured them. Apparently the only mention of those of Gobius pictus is by Holt and Byrne (1901) who give the size of the eggs as about 0.80 mm. high by 0.65 mm. broad. Gobius minutus and pictus often occur together in the Sound and at the mouth of the Cattewater, but pictus is chiefly to be found near coarse sandy bottoms such as one gets near Duke Rock and New Grounds. Gobius microps occurs usually higher up the rivers, but the eggs and young are to be found occasionally in the Sound in the same localities as minutus and pictus.

Shells with eggs on them are commonly dredged in the Sound, those between Plymouth and the Breakwater are usually minutus, but pictus eggs are dredged from New Grounds and microps sometimes in the Catte-water.

In order to distinguish the eggs of these three species, and especially to obtain the eggs of G. pictus, adults of all three species were isolated in separate tanks with shells on the bottom on which the fish laid their eggs. The adults of minutus were from the Cattewater, those of pictus from New Grounds, and microps from Chelson Meadow, which opens into the Laira and where the water varies much in salinity, from almost fresh to ordinary sea-water strength. G. minutus and pictus were put into the tanks into ordinary running sea-water, straight from the vessel in which they were brought in from the dredge.