690 TELEOSTEI chap. 



chenichtJiys. Oxuderces, which has been made the type of a distinct 

 family, appears to differ from Trypauchen only in the absence 

 of ventral fins. Fossils referred to Gobius have been described 

 from the Upper Eocene and Miocene of Europj, 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 Gardiitni, Patella, Haliotis, etc., 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 

 pyriforni, are stuck to the inner surface of the shell forming the 

 roo£^ A curious British form is Ajjhia pelhicicla, 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 

 {Tyflilogobius calif orniensis), 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 {Periopli- 

 thalmus), of which various species are found in great abundance 

 on the mud-flats at the mouths of rivers in tropical Africa, Asia, 

 and ISTorth-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 

 together.^ 



1 On the breeding habits and eggs, cf. F. de Filippi, "Mem. s. svlluppo del 

 Ghiozzo " {Ann. Univ. Med. Milano, 1841) ; Holt, Ann. Mag. Nat. Hist. (6), vi. 

 1890, p. 34; Petersen, Vid. Meddel. 1891, p. 243 ; Guitel, Ann. Mag. Nat. Hist. 

 (6) viii. 1891, p. 407, and Arch. Zool. HxpiSr. (2), x. 1892, p. 499, and (3) iii 1895, 

 p. 263. 



^ Cf. W. E. Eitter, Bull. Miis. Harvard, xxiv. 1893, p. 51. 



^ For a good figure from life of Pcriophthalmus koclrcuteri and an account of its 

 habits, cf. S. J. Hickson, A Naturalist in North Celebes (London, 1889). 



