SOUTHERN PIKELETS ARAPA1MAS 2851 



peculiarity is that the spawn falls into the cavity of the abdomen previous to its 

 exclusion. There are two Indian representatives of the genus, one of which grows 

 to a couple of feet in length; a third is Bornean, and the other two are West 

 African. An extinct species has been described from the Eocene of Sumatra. 



THE SOUTHERN PIKELETS Family GALAXIIDJE 



For want of a better name we may designate by the name of southern pikelets 

 a genus of small fresh-water fishes from the Southern Hemisphere, one of which 

 (Galaxias attenuatus) is represented in the lower figure of the illustration on p. 

 2849. Together with the members of the next family, these fishes are distinguished 

 from the other genera of the present sectional group noticed here by having the 

 base of the cranium simple, the tail being rounded or forked, and the pterotic bone 

 devoid of a cavity i its interior. Externally these fishes may be recognized by the 

 naked body and the absence of barbels; the fatty fin being absent, and the medium- 

 sized dorsal opposite the anal. Internally the air bladder is large and simple; and 

 the eggs, as in the last family, fall into the abdominal cavity. Represented by 

 rather more than a dozen species, the largest of which seldom exceeds eight inches 

 in length, these fish are of especial interest from a distributional point of view, 

 since they occur in such isolated areas as New Zealand, New South Wales, Tas- 

 mania, and the southern extremity of South America. From their spotted bodies, 

 the New-Zealand representatives of the genus were formerly known as trout by the 

 colonists. An allied New-Zealand genus (Neochanna}, represented by a single 

 species, differs in the absence of pelvic fins; all the known specimens of this singu- 

 lar form having been found buried in burrows of clay or hard mud at a considerable 

 distance from the water. 



THE ARAPAIMAS Family OSTEOGLOSSID^, 



Agreeing with the last family in the conformation of the base of the skull, the 

 large tropical fresh- water fishes, which may be collectively known as arapaimas (al- 

 though this name properly belongs only to the Brazilian species here figured), are 

 fully as interesting as the latter from their geographical distribution, which presents 

 a curious general similarity to that of the existing lungfishes, although in the pres- 

 ent instance one of the genera has a much wider range than either of the lung- 

 fishes. In confirmation of the northern origin of the present group, it is noteworthy 

 that an arapaima exists in Sumatra, and also that an extinct genus (Dapedoglossus) 

 occurs in the Eocene strata of the United States. From the preceding the more 

 typical representatives of this family are structurally distinguished by the upper 

 pharyngeal bones being three, instead of only two in number. Externally these 

 fishes have the body covered with large, hard scales of a mosaic-like structure; the 

 lateral line being formed by wide openings of the mucus canal; and the scaleless 

 head nearly covered with roughened ossifications of the skin. The margin of the 



