Solenorhynchus, from the Upper Eocene of North Italy, probably belongs to this family, but its form is much more elongate, and the exoskeleton is in regular rings.
Fam. 10. Syngnathidae.—Body more or less elongate, protected by an exoskeleton forming rings. Anterior vertebrae not elongate; parapophyses strong, ankylosed to the exoskeleton; no ribs. Snout much produced, tubiform; mouth small, terminal, toothless; no praeoperculum; symplectic elongate; gill-cleft reduced to a very small opening near the upper posterior angle of the gill-cover; gill-lamellae small rounded lobes. A single dorsal fin. Pectoral fins, if present, with very small pterygials; ventrals absent. Caudal fin often absent; tail sometimes prehensile.
Fig. 386.—Syngnathus pelagicus.
This family embraces about 175 marine species, and is represented over the greater part of the world. Principal genera: Siphonostoma, Syngnathus, Penetopteryx, Ichthyocampus, Nannocampus, Osphyolax, Urocampus, Doryichthys, Coelonotus, Stigmatophorus, Nerophis, Protocampus, Gastrotoceus, Solenognathus, Hippocampus, Acentronura, Phyllopteryx.
Remains are found in the Upper Eocene and Miocene beds of Europe, and have been referred to Siphonostoma and Syngnathus, and to the extinct genus Calamostoma. It is probable that Pseudosyngnathus, from the Upper Eocene of Monte Bolca, is the type of a distinct family.
The best known members of this family are the Needle-Fish or Pipe-Fish (Siphonostoma and Syngnathus) and Sea-Horse (Hippocampus) of our coasts. The latter, like Amphisile, swims with the body in a vertical position. In most species the male takes charge of the eggs, in a pouch under the tail (Siphonostoma, Syngnathus, Penetopteryx, Nannocampus, Stigmatophorus, Hippocampus), in a groove under the tail (Phyllopteryx), or in a groove on the abdomen (Doryichthys, Coelonotus, Nerophis, Gastrotoceus).
Fig. 387.—Hippocampus guttulatus. Male, showing brood-pouch (mp). a, Anus; b.a, branchial aperture.
