502 



MOLLUSC A. 



This species is cjilled the Hooked Squid, 0. Banksii. Its length from the tail to the end of 

 the tentacles is six feet. The two largest of these are furnished with suckers and hooks, which 

 enable the animal to seize its slippery prey with a powerful grasp. It appears that these 



creatures arc not only of large size, 

 but are truly formidable; the natives 

 of the islands of the Pacific who 

 dive for shell-fish have a great dread 

 of them. 



6^mMsCHEIR0TEUTHIS: Chei- 

 rotcuthis. — Of this there are two 

 species in the Atlantic and Mediter- 

 ranean. One of these, Bonelli's 

 Cheiroteutiiis, C. Bonelli, has the 

 body eight inches long, and the 

 longest tentacles nearly three feet. 



The Cephalopoda seem to con- 

 stitute a favorite form of existence 

 in the operations of nature. Not 

 only are the forms greatly diversi- 

 fied, but the species, swarming in 

 almost every part of the ocean, are 

 infinitely multiplied. Nevertheless, 

 in former ages of the world analo- 

 gous species were still more abund- 

 ant than are the present ones. 

 Of those kinds called Belemites, 

 which are now all extinct, the ves- 

 tiges of nearly a hundred species 

 have been discovered, distributed 

 throughout Europe. The soft parts 

 of these animals have perished 

 ages ago, and there now remain 

 only the internal shells or pens, 

 somewhat resembling those of 

 the living calamaries. Impressions, 

 however, of belemites are preserved 

 in some fine-grained strata, from 

 wliich it has been ascertained that they resembled the loligo in form, their arms having been 

 furnished with sharp hooks instead of suckers. It is supposed that these animals lived near 

 shores where they were in danger of striking against rocks and other fixed objects ; the shells 

 had a provision to prevent injuries from such a source. 



BONELLI S CHEIUOTEUTHIS. 



ORDER 2. TETRABRANCHIATA. 



This term, from the Greek tetra^ four, and the Latin hrancliia, a gill, alludes to the possession 

 of four gills by the several species of the order. The only existing kinds are those of the genus 

 Nautilus, of which three or four species are found in the Persian, Chinese, and Indian seas; 

 all the rest have perished, and are only known by their shells, which, however, are amazingly 

 abundant. All these animals resembled the cuttle-fishes ; they were carnivorous, and appear to 

 have served by their devastations to keep within bounds the mollusks, crustaceans, and fishes 

 that teemed in the waters of remote geological periods. They are divided into two families, the 

 Nautilidce and Ammonitidce. 



