CHIM^ROID FISHES AND THEIR DEVELOPMENT. 



of citations as to their phyletic position, every investigator will admit that Chim- 

 aeroids have been but little studied surprisingly little studied, if we consider the 

 morphological problems which they have trenched upon And in this regard we 

 may safely conclude that the obstacle in the way of the investigator has often 

 been a simple one lack of material for research. For, until recently, good material 

 of Chimsera was relatively rare. As a deep-water form, it was taken only by special 

 fishermen in special localities, and even then, since it was not a food-fish, it found its 

 way rarely to a market and still more rarely to a laboratory. This, then, has been 

 an obvious reason why embryological material was not early described. It may 

 finally be mentioned that fossil Chimaeroids, so important to the general discussion, 

 are rare, and, with very few exceptions, fragmentary. 



Recent Chimaeroids are included in 4 genera and about 25 species. An idea of 

 their distribution and size may be had by reference to the following table : 



TABLE A. Kinds, Localities, and Approximate Sizes of Recent Chimferoids. 



*By any remote possibility could this have been CallorhyncJtus centrina, which Gronow described from a speci- 

 men which he saw " in museo cl. Gaubii, Lugd. Batav. " ? (Syst.,ed. Gray, 1854, pp. 15-16.) His description suggests 

 Harriotta rather than Rhinochimaera, since "habitat in Oceano Americano." It is hardly conceivable, however, 

 that Gronow should have happened across this rare form, and from the general vagueness of the description and 

 in view of the absence of the type specimen the name CaUorkynchus centrina should be cast out of the systematic list. 



