190 The Scyphophori, Haplomi, and Xenomi 



as a distinct order, although no character of high importance 

 separates it from either. Hay unites the Haplomi with the 

 Synentognathi to form the order of Mesichthyes, or transitional 

 fishes, but the affinities of either with other groups are quite 

 as well marked as their relation to each other. Boulenger unites 

 the Iniomi with the Haplomi, an arrangement which apparently 

 has merit, for the most primitive and non-degenerate Iniomi, as 

 Aulopus and Synodus, lack both mesocoracoid and orbitosphe- 

 noid. These bones are characteristic of the Isospondyli, but are 

 wanting in Haplomi. 



There is no adipose dorsal in the typical Haplomi, the dorsal 

 is inserted far back, and the head is generally scaly. Most but 

 not all of the species are of small size, living in fresh or brackish 

 water, and they are found in almost all warm regions, though 

 scantily represented in California, Japan, and Polynesia. The 

 four families of typical Haplomi differ considerably from one 

 another and are easily distinguished, although obviously re- 

 lated. Several other families are provisionally added to this 

 group on account of agreement in technical characters, but 

 their actual relationships are uncertain. 



The Pikes. The Esocidce have the body long and slender 

 and the mouth large, its bones armed with very strong, sharp 

 teeth of different sizes, some of them being movable. The 

 upper jaw is not projectile, and its margin, as in the Salmonidcc, 

 is formed by the maxillary. The scales are small, and the 

 dorsal fin far back and opposite the anal, and the stomach 

 is without pyloric casca. There is but a single genus, Esox 

 (Lucius of Rafinesque), with about five or six living species. 

 Four of these are North American, the other one being found 

 in Europe, Asia, and North America. 



All the pikes are greedy and voracious fishes, very destruc- 

 tive to other species which may happen to be their neighbors; 

 "mere machines for the assimilation of other organisms." 

 Thoreau describes the pike as "the swiftest, wariest, and most 

 ravenous of fishes, which Josselyn calls the river-wolf. It is 

 a solemn, stately, ruminant fish, lurking under the shadow of 

 a lily-pad at noon, with still, circumspect, voracious eye ; motion- 

 less as a jewel set in water, or moving slowly along to take up 

 its position; darting from time to time at such unlucky fish 



