THE BRACHIOK>t>A 7 



different. Thus it is that the species obovata is no longer 

 called Terebratula, but Ornithella.* 



Shells such as these are not only found fossil in many 

 different strata; they are also dredged, with the animal 

 still living of which they form part, from the ocean in 

 most parts of the world. Altogether 112 species of 

 terebratuloids have been found in the exploration of the 

 sea, as well as forty-six other species which, though not 

 actual terebratuloids, are so near them in structure that 

 they are united with them in zoological classification 

 under the name Brachiopoda (or brachiopods). They are 

 purely marine in habitat, no species having ever been 

 found in any lake, river, or estuary ; the largest number 

 of species live on the bottom between the depths of 30 

 and 100 fathoms ; many species (and perhaps the greatest 

 number of individuals) live in shallower water than this, 

 even in a few cases above low-water mark ; only a few 

 species live in water beyond the loo-fathom line. The 

 coasts of Japan furnish the largest number of species for 

 any one area : those on the east and west coasts being 

 almost entirely different (20 species in eastern, u in 

 western waters, of which only 2 species are common 

 to both.) The geographical range of some species is 

 very wide, that of others very restricted. 



A living terebratuloid, such as Magellania flavescens of 

 the Southern Seas, lives attached to the sea bottom 

 (usually many individuals in a cluster) by a short 

 muscular stalk (pedicle) which emerges through the 



* For further explanation of the terms species, genus, family, etc., 

 see Chap. XII. 



