OF CONCHOLOGT. 117 



according to the locomotive organs, placing the whales lowest, 

 next to the Pinnipedia ; the rest being arranged according to 

 the development of the prehensile power of the locomotive 

 organs. 



Owens' system of the Mammalia, according to the generative 

 organs in Placentalia and Aplacentalia, reduced suddenly the 

 value of the locomotive organs as characters for higher divisions ; 

 placing the Whales over the Marsupialia, many of which have 

 prehensile limbs. But a still greater revolution, corresponding 

 to that called forth by Ray, was the same author's division ac- 

 cording to the anatomy of the brain (Gyrencephala, Lissen- 

 cephala), by which the Bruta, Cheiroptera, Insectivora and 

 Rodentia were removed below the Cetacea, close to the Marsu- 

 pialia. 



The locomotive organs, chiefly the legs, are still generally 

 considered as a natural base for the arrangement of the birds, 

 being in accordance with their buccal parts. The little import- 

 ance of the locomotive organs in the reptiles and fishes as char- 

 acters for superior divisions, has long since been proved. The 

 Lophobranchii are generally considered more allied to the fishes 

 than to the Amphibians, although they have scarcely more pro- 

 perties in common with the former than the fins, as in the 

 whales. 



According to Prof. Owen, the Lophobranchii, like the higher 

 animals, have a distinct thorax and abdomen ; the skull approxi- 

 mates more nearly to the type of cranial organization in the 

 lower forms of reptiles. Digestive and reproductive organs are 

 like those of the Amphibians. The respiratory organs are quite 

 different from those of the Teliosts, or true fishes, but agree with 

 those of the Amphibians chiefly in the young state. It seems 

 therefore probable that the Amphibians may be restored in the 

 original Linnean sense, as accidentally founded on an erroneous 

 observation of Dr. Garden. 



A close comparison by competent naturalists of the following 

 three series would at once prove the true relations between ttie 

 oceanic and terrestrial orders : 



1. Pachydermata. 



2. Sirenia. 



3. Cetacea. 



1. Patella. 



2. Dentalia. 



3. Cephalopoda. 



1. Batrachia. 



2. Ichthyodea. 



3. Lophubranchia. 

 Among Arthropoda the number of the locomotive organs is 



still considered the principal base for the classes ; it is only 

 lately that the apterous hexapod insects are put in their due 

 place according to their oral parts, and the Myriopoda degraded 

 to an order of Crustacea. The Molluscan system is generally 



