690 TELEOSTEI CHAP. 
chenichthys. Oxuderces, which has been made the type of a distinct 
family, appears to differ from Zrypauchen only in the absence 
of ventral fins. Fossils referred to Gobius have been described 
from the Upper Eocene and Miocene of Europe, but there is no 
satisfactory evidence that they really belong to this family. 
Gobius, of which several species are of common occurrence on 
our shores, have attracted special interest from their habits 
during the much prolonged breeding season. The male, usually 
more brilliantly coloured than the female, mounts guard over 
the eggs, which are either simply fixed by the female to the 
under surface of stones or weeds, or in a sort of nest built and 
kept in constant repair by him. This nest is usually made of 
a shell of Cardiwm, Patella, Halvotis, ete., or of the carapace of 
a crab, with the convexity turned upwards and covered with 
sand; the sand underneath is hollowed out, and a round opening 
at the side, coated by a mucus secreted by the skin of the male fish, 
gives access to the interior; the eggs, which are elongate and 
pyriform, are stuck to the inner surface of the shell forming the 
roof! A curious British form is Aphia pellucida, two inches 
long which, from its transparent and almost colourless body, has 
long been erroneously supposed to be the fry of some larger fish. 
Among exotic forms, mention should be made of the Blind Goby 
(Typhlogobius californiensis), two inches long, uniform light pink, 
scaleless, with the eyes very small, reduced to mere vestiges, 
covered by skin, and functional only in the young, living like 
a slug under rocks between tide marks on the coast of Cali- 
fornia;* and to the Walking-Fish or Jumping-Fish (Perioph- 
thalmus), of which various species are found in great abundance 
on the mud-flats at the mouths of rivers in tropical Africa, Asia, 
and North-West Australia, skipping about by means of the 
muscular, scaly base of their pectoral fins, with the head raised 
and bearing a pair of strongly projecting versatile eyes close 
ay 3 
together. 2 
1 On the breeding habits and eggs, cf. F. de Filippi, ‘‘ Mem. s. sviluppo del 
Ghiozzo” (Ann. Univ. Med. Milano, 1841); Holt, Ann. Mag. Nat. Hist. (6), vi. 
1890, p. 34; Petersen, Vid. Meddel. 1891, p. 248; Guitel, Ann. Mag. Nat. Hist. 
(6) viii. 1891, p. 407, and Arch. Zool. Expér. (2), x. 1892, p. 499, and (3) ili. 1895, 
p. 263. 
2 Cf. W. E. Ritter, Bull. Mus. Harvard, xxiv. 1893, p. 51. 
3 For a good figure from life of Periophthalmus koelreuteri and an account of its 
habits, cf. S. J. Hickson, A Naturalist in North Celebes (London, 1889). 
