. Animals of the past, an account of some of the creatures of the ancient world. Withsuch drawbacks as these to contend with, it canscarcely be wondered at that, while some natu-rahsts believe these little creatures to be relatedto the lamprey, others consider that they belongto a perfectly distinct group of animals, andothers stUl think it possible that they may bethe larval or early stages of larger and better-developed forms. StUl higher up we come upon the abundantremains of numerous small fish-hke animals,more or less completely clad in bony armor,indicating that they lived in troublous t
. Animals of the past, an account of some of the creatures of the ancient world. Withsuch drawbacks as these to contend with, it canscarcely be wondered at that, while some natu-rahsts believe these little creatures to be relatedto the lamprey, others consider that they belongto a perfectly distinct group of animals, andothers stUl think it possible that they may bethe larval or early stages of larger and better-developed forms. StUl higher up we come upon the abundantremains of numerous small fish-hke animals,more or less completely clad in bony armor,indicating that they lived in troublous timeswhen there was literally a fight for existenceand only such as were well armed or wellprotected could hope to survive. A parallelcase exists to-day in some of the rivers of SouthAmerica, where the little cat-fishes would pos- 24 ANIMALS OF THE PAST sibly be eaten out of existence but for the factthat they are covered — some of them verycompletely — with plate-armor that enablesthem to defy their enemies, or renders themsuch poor eating as not to be worth the Fig. 4. — Cephalaspis and Loricaria, an Ancient and aModem Armored Fish. The arrangement of the plates or scales in theliving Loricaria is very suggestive of the seriesof bony rings covering the body of the ancientCephalaspis, only the latter, so far as we know,had no side-fins: but the creatures are in no THE EARLIEST KNOWN VERTEBRATES 25 wise related, and the similarity is in appearanceonly. Pterichthys, the wing fish, was another small,quaint, armor-clad creature, whose fossilized re-mains were taken for those of a crab, and oncedescribed as belonging to a beetle. Certainlythe buckler of this fish, which is the part mostoften preserved, with its jointed, bony arms,looks to the untrained eye far more hke somestrange crustacean than a fish, and even natu-ralists have pictured the animal as crawhngover the bare sands by means of those samearms. These fishes and their allies were oncethe dominant type of f
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectpaleontology, bookyea
