The Pharyngognathi proper, having two nostrils on either side, smooth scales and the gills three and one-half, constitute four fam ilies, Labride, wrasse-fishes or doncellas, shoulder-girdle with the skull. The ventral fins in these fishes have one spine and five (rarely fewer) rays. The scales are small and often rough. The presence in the more primi tive forms of 24 vertebra and five soft rays in the ventrals indicates the common origin of these fishes with the members of the scombroid, percoid and labroid groups. While the more Odacides Siphonognathida and Scarida (Cal lyodontida) or parrot-fishes, in which the teeth are united to form a bird-like beak.
A large group of more or less related forms, primitive of the chatodontoid series much re semble primitive members of the other series, the extremes of the former represent a wide divergence, specialization and degeneration.
The typical families are the Ilarchide or spade-fishes, the Chtetodontide or butterfly fishes, characteristic of coral reefs, and the Zanclide or Moorish idols. Aberrant types are the Toxoida or arches, Ephippidce (Scato phagide), Antigoniidcr or and Dre pamdcr. Still more aberrant are the Acan thuride, tangs or the Siganidcr, with the last ventral rays spinous like the first. From the tangs are descended the degenerate types known collectively as Plectognathi, the bones of the jaws being more or less consoli dated. Three sub-orders exist among these forms, Sclerodermi, with separate rough scales and separate teeth, the Ostracodermi, with the body enclosed in a bony box, and the Gym nodontes, with the teeth coalescent into one or two plates in each jaw.
To the Sclerodermi belong the three fam ilies, Triacanthida, Balistidce or trigger-fishes, and Monacanthidcr or file-fishes. To the Ostra codermi belong the Ostraciace or and to the Gymnodontes, the Triodontide, the Tetraodontide or globefishes, the Tropidichthy Caracanthide, the Hexagrammide or green fishes, the AnoploPomicke or the Zaniolepide, the Ophiadontids or "blue cod,* the Erslepide or "fat priest" of Japan, the Scorpersidce or rose-fishes and sea-scorpions, the Platycephalidcr, the Bembrickr, the Hop lichthyide, the Cottide or sculpins, the Cyclop teride or the Liparididcr (Cyclo gasteride) or the Rhamphocottidat the Agonide, or the Triglicke or the Peristediide and the Cephalacanthide or flying gurnards. The last three families differ considerably in oste ology, and are segregated by Dr. Gill as the
Craniosni.
In the sub-order Discocephali the spinous dorsel fin is modified to form a sucking disc. This is placed on the head, and is made of two series of flat plates. There is one family, the Echineidide or remoras.
The large family of Gobiidcr forms a super family called Gobioidea. The gobies are dis tinguished by numerous minor traits, the re stricted gill-openings, the short spinous dorsal ids the Chonerhinida, the Diodontide or por cupine fishes, the Heptadiodontider (extinct), and the Molidw or head-fishes.
A small group known as the super-family Cirrhitoidea is characterized by the thickened and unbranched character of the lower pectoral rays, the third suborbital being at the same time not enlarged. Here belong the Cirrhitida, the Aplodactylidce, the Latridide and possibly the Trichodontids This group seems to mark a direct transition from the perch-like fishes to those with mailed cheeks.
The sub-order of mailed-cheek fishes, Parei oplite, is characterized by the presence of the suborbital stay, a process extending backward from the third suborbital to or toward the upward limb of the preopercle. This stay is subject to great exaggeration in some forms, while in others it is much reduced. It is, how ever, always present in these fishes and in no others. In the more primitive types the ven trals have one spine and five rays. There are 24 vertebra, and the scales are normally de veloped. In the extremes there are remarkable cases of specialization on the one hand and of degeneration on the other.
The families of mailed-cheek fishes are the and usual connection of the ventral fins among others. With the gobies may be associated the small family of Oxudercide.
To the sub-order Jugitlares we may refer many families which agree in having the ven tral fins inserted before the pectorals. The super-family Trachinoidea for the most part retain the normal number of ventral rays, the spine and five soft rays. To this group belong the Trachinide or weavers, the Uranoscopidcr or stargazers, the Percophide, Nototheniidce, Pteropsaride, Harpagifericr, Chenichthyide, Champsodontidce, Bovichthyidar, the Draconet tidce, or dragonets, the Platypt teride, and perhaps the Chiasmodonticke and Hemerocartids Other divergent or aberrant families in this neighborhood are the Comephoride or Baikal fishes, the Bathymasteride or ronquils and the GadoPside. The Batrachoidide or represent the group Haplodoci.