1896.] FISHES or the family GONOmiYNCHlDyE. . 503 



cranium is sepn from above, but the only clearly distinguishable 

 remains are those of the great pair of frontals (/r.). Some 

 characteristic portions of the small mouth are observable forwards 

 below ; one of the maxillsB (mx.), a dentary (rf.), and apparently a 

 fractured articulo-angular element (og.) being distinct. The bone 

 (.r) above the maxilla may perhaps bo part of the large preorbital 

 cheek-plate seen in Gonorhyachus (fig. 5). The right operculum 

 {op.) and suboperculum (s.op.) are displaced upwards above the 

 head, and the last-mentioned bone exhibits the four deep clefts 

 in its hinder border. Eemains probably of four large branchio- 

 etegal rays (hr.) occur below the head just in front of the rather 

 obscure pectoral arch. 



The total number of vertebrsB cannot be definitely ascertained, 

 but seems to be between 50 and 60. The centra resemble those 

 of the American fish, though a little shorter in proportion to their 

 depth ; and the state of preservation of one specimen (Brit. Mus. 

 no. P. 38S4) suggests that each centrum was pierced mesially by 

 the notochord. The delicate ribs are borne by stout processes 

 from the centra, as noted by Agassi'/., and as well shown in the 

 specimen of which the head has been described. The neural 

 spines are expanded in the anterior part of the abdominal region, 

 as also shown in the same specimen and indicated by Agassiz 

 in fig. 3 of his plate representing the species. The extremity of 

 the vertebral column is formed precisely as described above in 

 N. osculux, the lowermost expanded hsemal spine at tiie base of 

 the caudiil fin being distinctly supported by the hinder border of 

 the penulHniate centrum; this, however, mnst be displaced for- 

 wards, for both the penultimate and the antepenultimate centrum 

 bears its own ha?mal arch, comparatively stout but not expanded. 



The firis appear to resemble those of N. or.calus, but there are 

 only eleven supports in the dorsal (clearly shown in Brit. Mus. 

 no. 43436). the foremost with a wing-shaped expansion indicating 

 its composite character. It is difficult to count the rays them- 

 selves, the two halves of each being so loosely apposed that iu 

 crushing they frequently slip one behind the other. 



The sciiles are comparatively thick, and in their crushed state 

 they rarely exhibit the posterior fringe of denticles. Careful 

 examination of many specimens, however, shows that they pre- 

 cisely resemble those of Gonorhijnchus. A detached scale from 

 the hinder end of the caudal region is represented oE the natural 

 size in PI. XVIII. fig. 4. The radiating grooves in its deeply over- 

 lapped portion are distinct, and the hinder fringe is partly restored 

 from an adjoining scale. 



3. NOTOGONHTJS CtTTIEUI. 



(?)1818. Anormiims macrolepidotus, H. D. de Blainville, Nouv, 

 Diet, d'llist. Nat. vol. xxvii. p. 374. 



1822. "Cyprin," G. Cuvier, Oss. Foss. ed. 2, p. 346, pi. Ixxvii. 

 fig. 15. 



1844. Sphenolepis cuvieri, L. Agassi/,, Poiss. Poss. vol. v. pt. i. 

 p. 13, pt. ii. p. S'd, pi. xliv, figs. 1, 2 (? figs. 4-12, nee fig. 3). 



