332 Mr. C. T. Regan on the 



parapopliyses to whicli the ribs are attached. Eoth jaws 

 strongly produced, furnished with bands of small teeth and 

 with a single series of more or less strongly enlarged, erect, 

 conical, pointed teeth. No finlets. 



Synopsis of the Genera. 



I, Gill-rakers developed ; jaws comparatively slender ; enlarged teeth 



of upper jaw moderate, of lower comparatively small and close- 

 set ; lower pharyngeal triangular ; second and third upper pha- 

 ryngeals dentigerous ; fourth usually distinct, dentigerous. 



Body scarcely or moderately compressed . 1. Belone, Cuv., 1817 *. 



Body very strongly compressed 2. 2'etalichthi/s, Regan, 1904. 



II. Gill-rakersabsent or vestigial; jaws comparatively stout ; enlarged 



teeth of both jaws strong, spaced canines. 



A. Dorsal rays subequal ; lower pharyngeal triangular; second, 



third, and fourth upper pharyngeals separate, dentigerous. 



3. Fotamorrhaphis, Giinth., 

 [1866. 



B. Anterior dorsal rays forming a lobe ; lower pharyngeal elon- 



gate, narrow, tlie dentigerous plate scarcely expanded poste- 

 riorly ; second and third upper pharyngeals dentigerous ; fourth 

 usually distinct, dentigerous. 



Body scarcely or moderately compressed . 4. Tylosunis, Cocco, 1829. 



Body strongly compressed 5. Athlennes, Jord., 1886. 



C. Anterior dorsal rays forming a lobe ; lower pharyngeal small, 



narrow, pointed or rounded at both ends ; only one pair of 

 dentigerous upper pharyngeals, the third. 



6. Xenentodon, gen. nov. 



I have examined the pharyngeal dentition in the following 

 species : — Belone belone, Linn., acus, Risso, trachura^ Cuv. & 

 Val., platura, Benn., yracilis, Lowe ; Petalichthys capensis, 

 Regan ; Tylosurus acus, Lacep., marinus, Walb., annulatus, 

 Cuv. & Val., robustus, Giinth., caiidimaculatus , Cuv., strongy- 

 lurus, Bleek., anastomella, Cuv. & Val. ; Athlennes Mans, 

 Cuv. & Val. ; Xenentodon cancila, Buch. Ham., canciloides^ 

 Bleek. 



The lower pharyngeal plate of Xenentodon seems to be 

 derived from tliat of Tylosurus by the constriction off of the 

 anterior part and disappearance of the remainder. 



* According to the synonymy given by Dr. Gill, Eaphistoma, Rafinesque, 

 1815, has priority over Belone, (Juv., 1817. Eatinesque (' Analyse de la 

 Nature,' p. 89j placed liaphistoma after Esox in the subfamily Esoxidia 

 ("Une seule nageoire dorsale; dos non aguillonue") of the family Siagonia 

 (" Machoires tres-prolongees, dent(5es") of the order Gastripia (" Les 

 abdominaux "). The only generic diagnosis is a reference to Belone, Gr. 

 [Gronovius]. As the name Belone apparently does not occur in the 

 writings of Gronovius, RapJdstoma may be regarded as a nomen nudum. 



