314 



GENERAL SUMMARY TO 



Dall, a distinguished American naturalist, is strongly opposed to the idea of placing 

 the Brachiopods among the Annelida; and in order that the reader may become 

 acquainted with both sides of the question we must refer him to Dall's paper in the 

 'American Journal of Science' for 1871. Therein he maintains, after a lengthened 

 comparison between the Annelids and Brachiopods, that these last are allied to other 

 groups, including the " Molluscoidea," and, through their combined characters, to the 

 typical Mollusca. He adds the following tabular comparison, which will illustrate the 

 differences in the characters of real value in the several groups : 



Mollusca vera. 



Brachiopoda. 



Annelida. 



Subcesophageal ganglion present; 



Subcesophageal ganglion present ; 



Ganglion supracesophageal ; and 



others scattered, not in a sub- 



others scattered, not in a sub- 



a subabdominal chain. 



abdominal chain. 



abdominal chain. 





Possessing a heart with or with- 



Heart and pulsatile vesicles pre- 



Without a heart, and sometimes 



out pulsatile vesicles. 



sent. 



without vessels. 



Intestine always bent. 



Intestine bent. 



Intestine usually straight, some- 

 times bent. 



Fixed organically or free. 



Fixed organically or free. 



Always free or not organically 

 fixed. 



Setse rarely present. 



Setae sometimes present. 



Setae present usually. 



With or without organically 



With organically attached calca- 



Without organically attached cal- 



attached calcareous shells. 



reous shells. 



careous shells. 



Mon- or dioecious, with oviducts. 



Mon- or dicecious, with oviducts. 



Mon- or dioecious, with or with- 

 out oviducts. 



Always reproducing by eggs. 



Always reproducing by eggs. 



Reproducing by eggs or fission. 



No sexual metamorphosis. 



No sexual metamorphosis. 



Often with two sexual forms. 



Aquatic or terrestrial. 



Aquatic. 



Aquatic or terrestrial. 



Dall adds that it does not seem possible that any modern naturalist should seriously 

 homologize the integument of a Worm with the shell of a Brachiopod. Such a homology 

 is its own best refutation. As for the rest, where is the "hardened integument" of 

 Planaria, or the Tremaioda, or the Uirudince ? Where are the muscles by which they 

 are attached to their " bivalve or multivalve shells ? and how are those muscles attached ? 

 Homologies and muscles fail in such an emergency." 1 



Stoliczka agrees with the conclusions advocated by Dall ; and adds, in vol. iv of the 

 ' Palaeontologia Indica, Brachiopoda,' " There cannot be much doubt as to the true Mol- 

 luscous character of the Brachiopoda, and their proper classification between the Anomiidae 

 of the Pelecypoda and the Saccopoda and the arm-bearing section of the Ciliopoda." 



1 In 1870 Mr. Morse published in the 'American Journal of Science and Arts,' vol. iv, p. 4, a" Reply 

 to Mr. Dall's Criticism on ' The Brachiopoda, a Division of Annelida.' " I regret I have not been able to 

 make myself acquainted with the contents of that paper. 



