OF CONCHOLOGY. Go 



The branchiae are anterior and external in Serpula, posterior 

 and internal in Bonellia and many G-ephyrea, and rarely form 

 a continuous disk encircling the mouth, as is universal in Bra- 

 chiopoda. 



Most, if not all, of the true Annelids are provided with a 

 "trompe," a curiousorgan contained within the oesophageal 

 cavity, exsertile, and usually furnished with denticles; and many 

 of the Annelids have strong horny jaws or lateral mandibles, 

 somewhat as in insects; none of these structures are found in 

 the entire group of Molluscoidea, including the Brachiopoda. 



In fact, if the typical characters of the Annelids as a group 

 are compared with those of the Brachiopods, it will be seen that 

 all the important features of each are incompatible or diametri- 

 cally opposed to those of the other group, respectively.* 



That the Brachiopods forma "comprehensive type," in the 

 wide sense in which Prof. Morse seems to imply, I cannot admit, 

 as they are a well-defined group whose characters as here shown 

 (I trust and believe impartially), are distinctly allied to those 

 of the other groups included in the Molluscoidea and, through 

 their combined characters, to the typical Mollusca. That they 

 are a peculiar group, exhibiting a few characters not shared by 

 their associates, and indicating a distant affinity with animals 

 not included in the type or sub-kingdom, I am willing to allow. 

 That these faint evidences are sufficient to authorize their depor- 

 tation and degradation to a subordinate place among the Anne- 

 lids, I consider unreasonable. 



In the light of the facts previously set forth I will now proceed 

 to sift the homologies and asserted affinities claimed by Prof. 

 Morse in his original paper f and his subsequent publications. I 

 should have preferred to await the publication of his complete 

 memoir, but it may safely be assumed that had he possessed any 

 more cogent arguments he would not have failed to bring them 

 forward, and the facts upon which my own arguments are based 

 are mostly of long standing and unquestioned by any one, so 

 that they can hardly be affected in any way by Prof. Morse's 

 coming work. 



Prof. Morse's remarks are in italics, for brevity and to save 

 tautology. 



*Quatrefages defines the Annelids as " essentially dioecious animals, 

 composed of segments which repeat themselves and bear on each side a 

 perfectly characteristic organ — a foot armed with exsertile and retractile 

 sette." But the learned savant does not include the Oligochasta and 

 Gephyrea, as do most modern naturalists. Cf. An. Mag. Nat. Hist, 

 xvii, p. 5, 1866. 



t Am. Journ. Sci. Arts, Vol. 50, July, 1870. 



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