E. C. Starks, in an important paper on "The Shoulder Girdle and Characteristic Osteology of the Hemibranchiate Fishes" (Proc. U.S. Nat. Mus. xxv. 1902, p. 619), has shown that the so-called infraclavicle of Sticklebacks and allies does not exist as a distinct element. The definition of the Catosteomi, as I had originally drawn it up, has accordingly had to be modified.
Proc. U.S. Nat. Mus. xxvi. 1903, p. 915.
On the nesting habits, cf. Coste, Mém. Acad. Sci. Paris, x. 1848, p. 575, Pl.; Warington, Ann. Mag. Nat. Hist. (2) x. 1852, p. 276; Prince, Ann. Mag. Nat. Hist. (5) xvi. 1885, p. 487, Pl. xiv. On the spinning organ: Möbius, Arch. Mikr. Anat. xxv. 1886, p. 554, Pl. xxii.
Dr. Sauvage has described a Gastrosteus texanus, but the locality is probably incorrect, as recent American works do not mention the occurrence of Sticklebacks in Texas.
Protaulopsis, from Monte Bolca, appears to me to belong to the Scombresocidae. The anterior vertebrae are equal in size; long, slender ribs are present, the body is scaly, and the so-called infraclavicles are absent. The rostrum is so much crushed that no opinion can be formed as to its structure.