322 CnARACINID.E. 



Tetragonopterus linnsei, Cuv. i^- Vol. xxii. p. 142. 



groiiovii, Cuv. Sf Val. xxii. p. 143 ; Ktier, Deiikschr. Acnd. Wiss. 



Wieu, 1859, x\-ii. p. 175. 

 Cliavax bimaciilatus, Gronov. Si/st. ed. Gray, p. 154. 

 Tetragonopterus vittatus, Casteln.Anim. Amei-. Sud, Poiss. p. 66. pi. 33. 



fig- 3. 



D. 11. A. 31-34. L. lat. 39. L. transv. 7/7f 



The height of the body is contained twice and two-fifths in the 

 total length (without caudal), the length of the head four times ; in 

 young specimens the head is, comparatively, somewhat larger. Inter- 

 orbital S2)ace very convex, its width being more than the diameter 

 of the eye, which is two-sevenths of the length of the head. The 

 upper profile is a httle concave above the parietal region. The 

 maxillary extends somewhat beyond the fi'ont margin of the eye. 

 The vertical from the origin of the dorsal fin falls behind the root of 

 the ventrals ; the pectoral reaches a little beyond the root of the 

 ventrals. A round black spot behind the shoulder ; a blackish blotch 

 on the base of the caudal fin, more distinct in young individuals 

 than in old ones ; both spots are united in young individuals by a 

 silvery band, which is sometimes blackish along the middle. 



Guianas, Brazil. 



a-c, d-f. Adult, half-grown, and young. British Guiana. 



g-k. Adult. Demerara. Presented by Dr. Hancock. 



l~m. Half-grown. River Capin. Purchased of Mr. Stevens. 



n-o. Half-grown and young. Pernambuco. Presented by J. G. E. 



Smith, Esq. 

 2^. Half-grown. Purchased of Mr. Frank. 

 q. Adult : skin. From Gronow's Collection. — Type of the species. 



12. Tetragonopterus fasciatus. 



Chalceus fasciatus, Ciiv. Mem. Mus. v. p. 352. pi. 26. fig. 2 *. 



? Tetragonopterus rutilus, Jenyns, Zool. Beaqle, Fish. p. 125. tab. 23. 



fig. 2. 

 Tetragonopterus fasciatus, Cuv. i^ Val. xxii. p. 149. 



D. 11. A. 25-29. L. lat. 35-39. L. transv. f. 



6 



The height of the body is contained twice and three-fifths or twice 

 and two-tliirds in the total length (without caudal), the length of the 

 head four times or four times and a half. Interorbital space convex, 

 its width being more than the diameter of the eye, which is two- 

 sevenths of the length of the head. The upper profile is very little 

 concave above the parietal region. The maxillary extends distinctly 

 beyond the vertical from the front margin of the eye. The origin of 



* This figure is evidently taken from a dry example, and is very inacciu-ate ; 

 Cuvier himself says in the description that the lateral line is composed of forty 

 scales, and that there are twelve longitudinal series. The figure, however, re- 

 presents much smaller scales. A similar discrepancy exists between the descrip- 

 tions of Cuvier and of Valenciennes ; whilst the former has counted eighteen 

 anal rays, the latter states twenty-five. 



