=The Shrimp-fishes: Centriscidæ.=—One of the most extraordinary types of fishes is the small family of _Centriscidæ_, found in the East Indies. The back is covered by a transparent bony cuirass which extends far beyond the short tail, on which the two dorsal fins are crowded. Anteriorly this cuirass is composed of plates which are soldered to the ribs. The small toothless mouth is at the end of a long snout. [Illustration: FIG. 186.—Shrimp-fish, _Æoliscus strigatus_ (Günther). Riu Kiu Islands, Japan. ] These little fishes with the transparent carapace look very much like shrimps. _Centriscus scutatus_ (_Amphisile_) with the terminal spine fixed is found in the East Indies, and _Æoliscus strigatus_ with the terminal spine movable is found in southern Japan and southwards. [Illustration: FIG. 187.—_Æoliscus heinrichi_ Heckel. Eocene of Carpathia. Family _Centriscidæ_. (After Heckel.) ] A fossil species, _Æoliscus heinrichi_, is found in the Oligocene of various parts of Europe, and _Centriscus longirostris_ occurs in the Eocene of Monte Bolca. In the _Centriscidæ_ and _Macrorhamphosidæ_ the expansions of the hypocoracoid called infraclavicles are not developed. =The Lophobranchs.=—The suborder _Lophobranchii_ (λοφός, tuft; βραγχός, gill) is certainly an offshoot from the _Hemibranchii_ and belongs likewise among the forms transitional from soft to spiny-rayed fishes. At the same time it is a degenerate group, and in its modifications it turns directly away from the general line of specialization. The chief characters are found in the reduction of the gills to small lobate tufts attached to rudimentary gill-arches. The so-called infraclavicles are present, as in most of the _Hemibranchii_. Bony plates united to form rings take the place of scales. The long tubular snout bears the short toothless jaws at the end. The preopercle is absent, and the ventrals are seven-rayed or wanting. The species known as pipefishes and sea-horses are all very small and none have any economic value. They are numerous in all warm seas, mostly living in shallow bays among seaweed and eel-grass. The muscular system is little developed and all the species have the curious habit of carrying the eggs until hatched in a pouch of skin under the belly or tail; this structure is usually found in the male. =The Solenostomidæ.=—The _Solenostomidæ_ of the East Indies are the most primitive of these fishes. They have the body rather short and provided with spinous dorsal, and ventral fins. The pretty species are occasionally swept northward to Japan in the Black Current. _Solenostomus cyanopterus_ is a characteristic species. _Solenorhynchus elegans_, now extinct (with the trunk more elongate), preceded _Solenostomus_ in the Eocene of Monte Bolca.