ZOOLOGY. 289 



a common stock, of a type to which the existing Annelids 

 are the nearest relations ; that the central chain and oesopha- 

 geal ganglion of the Arthropods and worms correspond to 

 the spinal chord and brain of the Vertebrates; and that the 

 nerves proceeding from the ganglionic chain re jj resent the 

 spinal nerves. The presence in worms of a notochord, the 

 mode of development of the heart, the situation of the prin- 

 cipal vessels, the course of the blood, and the position of the 

 segmental organs in those animals all testify to the rela- 

 tionship of the animals under consideration ; but of more 

 significance than all is the development: the evolution is 

 doubly symmetrical in the Annelids, and thus agrees with 

 that which has been observed in the Articulates and higher 

 animals, and in the last are traces of that opposition of the 

 cephalic and anal regions which is so characteristic of the 

 Annelids. In fine, Professor Semper believes that the Anne- 

 lids, Arthropods, and Vertebrates belong to one great group, 

 of which the Annelids are the most generalized and the Ver- 

 tebrates the most aberrant type. 



Fishes of the United States. 



The additions to the fish fauna of the United States have 

 been numerous, and several of them especially noteworthy. 

 The species of the fresh as well as salt waters have also been 

 so tar studied as to enable us to form an approximate idea 

 of the wealth of our fauna. The species of the eastern coast 

 are not far from 500 in number; those from the western, 

 so far as known, amount to nearly 400. Of the fresh- water 

 species over 600 appear to be tolerably well discriminated. 



The most interesting species added to the east-coast fauna 

 have been obtained from certain banks, or in moderately 

 deep water at some distance from the shore-line. Among 

 them are several species previously only know T n from the 

 high north : such are the Stichceus punctatus, Eumicrotremus 

 spinosus, Icelus uncinatics, and Triglops Pingelii, most of which 

 had been found in Greenland or equally northern waters, 

 but all of which were discovered during the past summer 

 off the coast of the United States at depths of from sixteen 

 to ninety fathoms ; others were new to science. They have 

 been described by Professor Goode and Dr. Bean under the 

 names Macrurus Bairdii and Lycodes Verrillii, and one bv 



