32 The Ganoids 



ward curve at the extremity, when finally there appears the 

 beginning of a lobe underneath, pointing to a complete hetero- 

 cercal tail. All this is as in the bony fishes, but this is the 

 permanent condition of the garpike, while in the bony fishes 

 the extremity of the dorsal cord becomes extinct. The mode 

 of development of the pectoral lobe (very large in this species) 

 furnishes another resemblance. In the brain, and in the mode 

 of formation of the gills, a likeness to the sharks is noticeable. 

 The young garpikes move very slowly, and seem to float quietly, 

 save an exceedingly rapid vibration of the pectorals and the 

 tip of the tail. They do not swim about much, but attach 

 themselves to fixed objects by an extraordinary horseshoe- 

 shaped ring of sucker-appendages about the mouth. These 

 appendages remain even after the snout has become so extended 

 that the ultimate shape is hinted at; and furthermore, it is 

 a remnant of this feature that forms the fleshy bulb at the end 

 of the snout in the adult. The investigations thus far show 

 that the young garpike has many characteristics in common 

 with the sharks and skates, but it is not so different from the 

 bony fishes as has been supposed." 



Fossil Garpikes. A number of fossil garpikes, referred by 

 Cope to the genus Clastes and by Eastman and Woodward to 

 Lepidosteus, are found in the Eocene of Europe and America. 

 The most perfect of these remains is called Lepisostens atrox, 

 upward of four feet long, as large as an alligator-gar, which the 

 species much resembles. Although found in the Eocene, Dr. 

 C. R. Eastman declares that " it has no positively archaic features. 

 If we inquire into the more remote or j>re-Eocene history of 

 Lepidosteids, palaeontology gives no answer. They blossom 

 forth suddenly and fully differentiated at the dawn of the 

 Tertiary, without the least clue to their ancestry, unheralded 

 and unaccompanied by any intermediate forms, and they have 

 remained essentially unchanged ever since." 



Another fossil species is Lepisosteus fimbriatus, from the 

 Upper Eocene of England. Scales and other fragments of 

 garpikes are found in Germany, Belgium, and France, in Eocene 

 and Miocene rocks. On some of these the nominal genera 

 Naisia, Trichiurides, and Pneumatosteus are founded. Clastes, 

 regarded by Eastman as fully identical with Lepisosteus, is said 



