The Gobies (_Gobiidæ_) form another interesting family of small littoral fishes, easily distinguished by the fact that the ventral fins are united in such a manner that they enclose a conical cavity. The first portion of the dorsal fin has also six flexible spines. The Spotted Goby (_Gobius minutus_) is commonly to be found on sand-banks, where it is well protected by the colouring of its upper surface, which closely resembles that of the sand on which it rests. It is said to make a nest by cementing fragments together round some little natural hollow, or to utilise an empty shell for a similar purpose, fixing the shell to the surrounding bed, and constructing a tunnel by which it can enter or leave. The eggs are deposited in this nest, and the male keeps guard over the home. The Black or Rock Goby (_G. niger_) inhabits rocky coasts, clinging to the rocks by means of a sucker formed of the modified pelvic fins. A brightly coloured fish known as the Dragonet (_Callionymus lyra_) is sometimes classed with the Gobies, though its pelvic fins are not united. It is not a well-known species, and is seldom obtained except with the dredge, as it inhabits deep water. [Illustration: FIG. 241.--THE BLACK GOBY] A peculiar little fish called the Pogge or Hook-nose (_Agonus cataphractus_), also known as the Armed Bull-head, is commonly taken in shrimpers’ nets on the south and east coasts. Its head and body are very angular, and are covered with an armour of keeled scales. It seldom exceeds six inches in length, and is classed with the Flying Gurnards in the family _Dactylopteridæ_. [Illustration: FIG. 242.--THE FATHER LASHER] The true Gurnards and the Sea Bullheads form the family _Cottidæ_. Several species of the former are included among our food-fishes, and are therefore more or less familiar to our readers. They are characterised by their large, square, bony heads, and by the finger-like rays of the pectoral fins which are used as organs of touch and for creeping along the bottom of the sea. The Bullheads are represented by the peculiar Father Lasher or Sting Fish (_Cottus bubalis_), which is very common on our rocky coasts and is frequently captured in shrimp nets. Its head and cheeks are armed with sharp spines which constitute formidable weapons of offence. When taken out of the water it distends its gills enormously; and, unless very cautiously handled, its sharp spines may be thrust deeply into the flesh. Young specimens, with imperfectly developed spines, may be seen in almost every rock pool, and the full-grown fish is easily taken with rod and line by fishing in the deep gulleys between the rocks.