334 On the Classification of the Order Syneyitognathi, 



Family 1. HemirhampMdae. 



Praemaxillaries anteriorly forming a flat triangular ex- 

 pansion ; maxillaries firmly united to prremaxillaries ; teeth 

 in jaws small, compressed, usually tricuspid; third upper 

 pharyngeals ankylosed. Vertebrae 49 to 55 ; parapophyses 

 strong, nearly horizontal. Pectoral fins short or moderately 

 long. 



Genera : Cohitopsis (probably including Chriodoruft) , 

 Arrhamphus, Hemirhamphus, Hemirhamphodon, Zenarcho- 

 pterits, Dermatogenys, Oxyporhamphus, Euleptorhamphus. 



Hemirhamphus occurs in the Upper Eocene of Moute 

 Bolca. 



Cobitopsis aciittis, from the Lower Miocene of France, is 

 very closely related to Chriodorus atherinoides from the coast 

 of Florida. Dr. Smith Woodward has permitted me to 

 examine exam. pies of the extinct species, which I have com- 

 pared with specimens of C. atherinoides. The two agree in 

 almost every detail ; the form, position, and structure of the 

 fins and the number of rays are exactly the same ; the jaws, 

 opercles, pectoral arch, &c. are extremely similar in the two 

 species, and the number of vertebrse is nearly or quite 

 identical^ In an example of Chriodorus atherinoides I count 

 16 dorsal, 17 anal, 12 pectoral, 6 pelvic, and 13 branched 

 caudal rays, and I find these numbers also in Cobitopsis 

 acutus ; I find 49 vertebrae in C. atherinoides, and approxi- 

 mately this number in C. acutus. 



In making a restoration of the extinct species Dr. Smith 

 Woodward* hasevidently been influenced by Mr. Boulenger's 

 opinion that this fish was related to Ammodytes. The broad 

 cleithrum of the Hemirhamphidse is represented as the 

 enlarged suboperculum of the Ammodytidse, and the pectorals 

 are shown as symmetrical and placed low, wbereas they 

 appear to me to be asymmetrical and placed high. C. acutus 

 has usually been described as toothless, but I believe that I 

 can recognize traces of small teeth in the jaws of one of the 

 specimens. 



In C. acutus the head is longer than in C. atherinoides, 

 measuring more than ^ of the length of the fish to the base 

 of the caudal, the lower jaw seems to be longer, more than | 

 the length of the head, and the snout is apparently more 

 produced. 



* Cat. Fossil Fish. ir. p. 3oo (1901). 



