_Boops boops_ and _Boops salpa_, known as boga and salpa, are elongate fishes common in the Mediterranean. Other Mediterranean forms are _Spondyliosoma cantharus_, _Oblata melanura_, etc. _Girella nigricans_ is the greenfish of California, everywhere abundant about rocks to the south of San Francisco, and of considerable value as food. Almost exactly like it is the Mejinadai (_Girella punctata_) of Japan. The best-known members of this group belong to the genus _Kyphosus_. _Kyphosus sectatrix_ is the rudder-fish, or Chopa blanca, common in the West Indies and following ships to the northward even as far as Cape Cod, once even taken at Palermo. It is supposed that it is enticed by the waste thrown overboard. _Kyphosus elegans_ is found on the west coast of Mexico, _Kyphosus tahmel_ in the East Indies and Polynesia, and numerous other species occur in tropical America and along the coasts of southern Asia. _Sectator ocyurus_ is a more elongate form of rudder-fish, striped with bright blue and yellow, found in the Pacific. _Medialuna californiensis_ is the half-moon fish, or medialuna, of southern California, an excellent food-fish frequently taken on rocky shores. Numerous related species occur in the Indian seas. [Illustration: FIG. 288_a_.—Blue-green Sunfish, _Apomotis cyanellus_ (Rafinesque). Kansas River. (After Kellogg.) ] Fossil fragments in Europe have been referred to _Boops_, _Spondyliosoma_, and other genera. CHAPTER XX THE SURMULLETS, THE CROAKERS AND THEIR RELATIVES [Illustration: FIG. 289.—Red Goatfish, or Salmonete, _Pseudupeneus maculatus_ Bloch. Family _Mullidæ_ (Surmullets.) ] =THE Surmullets, or Goatfishes: Mullidæ.=—The _Mullidæ_ (Surmullets) are shore-fishes of the warm seas, of moderate size, with small mouth, large scales, and possessing the notable character of two long, unbranched barbels of firm substance at the chin. The dorsal fins are short, well separated, the first of six to eight firm spines. There are two anal spines and the ventral fins, thoracic, are formed of one spine and five rays. The flesh is white and tender, often of very superior flavor. The species are carnivorous, feeding chiefly on small animals. They are not voracious, and predaceous fishes feed freely on them. The coloration is generally bright, largely red or golden, in nearly all cases with an under layer, below the scales, of red, which appears when the fish is scaled or placed in alcohol. The barbels are often bright yellow, and when the fish swims along the bottom these are carried in advance, feeling the way. Testing the bottom with their feelers, these fishes creep over the floor of shallow waters, seeking their food. The numerous species are all very much alike in form, and the current genera are separated by details of the arrangement of the teeth. But few are found outside the tropics.