342 CHAEACINID^. 



4. Chalcinus elongatus. 

 D. 11. A. 28. V. 8. L. lat. 45*. L. transv. ^. 



The height of the body is one-fourth of the total length (without 

 caudal), the length of the head one-fifth ; interorbital space very- 

 convex, its width being scarcely more than the diameter of the orbit, 

 which is contained thrice and one-third in the length of the head. 

 The maxillary extends to the vertical from the front margin of the 

 orbit ; adipose eyeUds well developed. The third (largest) infra- 

 orbital is nearly thrice as long as broad, its width being not much 

 more than one-half of the diameter of the eye. Operculum two- 

 thirds as long as high, not extending to the vertical from the axil. 

 The scales in the thoracic region are much larger than those on the 

 sides, nearly thrice as high as long. The distance of the origin of 

 the dorsal fin from the root of the caudal is contained once and two- 

 thirds in its distance from the extremity of the snout. The anal 

 commences immediately behind the last dorsal ray. Caudal forked, 

 wth the middle rays produced into a lobe. The length of the head 

 is contained once and two-thirds in that of the pectoral fin, which 

 extends nearly to the extremity of the ventral fin. Uniform silvery. 



Hal. ? 



a. Ten inches long. From the Collection of the Zoological Society. 



29. GASTROPELECUS. 



Gasteropelecus, Gronov. Mus. Ichth. ii. p. 7. 



Dorsal fin placed behind the middle of the length of the body, 

 above the anal ; anal long ; pectoral long ; ventrals veiy small, or 

 rudimentary. Body strongly compressed, with the thoracic region 

 dilated into a siibsemicircular disk. Scales of moderate size. Lateral 

 line descending obhquely backwards towards the origin of the anal 

 fin. The lower profile compressed into an acute ridge. Cleft of the 

 mouth of moderate width ; teeth compressed, tricuspid, in one or 

 two series in the intermaxillary, and in a single in the mandible ; 

 maxillary with a few minute conical teeth ; palate toothless. Nos- 

 trils close together. GUI-openings very wide, the gill -membranes 

 not attached to the isthmus ; gill-rakers slender, lanceolate. 



Brazil; Surinam. 



1. Gastropelecus sternicla. 



Gasteropelecus, Gronov. Mus. Ichth. ii. p. 7. no. 255. tab. 7. fig. 5. 



Clupea sternicla, L. Syst. Nat. ed. 10. i. p. 319 ; Koelrmter, Comment, 

 Nm. Vetrop. 1761, \iii. p. 405. tab. 14. figs. 1-3. 



Gasteropelecus sternicla, Pall. Spic. Zool. fasc. 8. p. 50. tab. 3. fig. 4 ; 

 Cuv. 4- Val xxii. p. 169. pi. 640 ; Xner, JDenkschr. Acad. Wiss. Wim, 

 1860, xviii. p. 16 ; Gronov. Syst. ed. Gray, p. 171. 



* The scales have been counted in the series commencing from the upper end , 

 of the gill-opening. 



