T. Davidson — What is a Brachiopod ? 
265 
announced so positively, from the histovy of the American Brachio- 
poda alone, the vertniform affinities of the Brachiopods now so con- 
clusively proved by the development of Argiope in Kowalevsky’s 
paper.” 
No one can doubt that the Brachiopods and Amphi tri tes possess 
many important characters in common after perusing the admirable 
observations upou the subject coutained in Prof. Morse’s memoir ; 
but, at the same time, as was remarked to me by Prof. Verrill, 
almost any invertebrate group may be annelidelized by overrating 
certain points of its affinities ; and, it seems to me, that one must not 
place entire confidence in any Classification which is founded to so 
great an extent on embryological characters. It may turn out, how- 
ever, that the Brachiopoda really constitute a division of the Annelids. 
The setae do not appear to be a constant character, and the tendinous 
peduncle of the Terebratulidse seems very different from the annu- 
lated structure which Morse describes in Lingula, and it appears, 
according to Dr. J. Gwyn Jeffreys, to closely resemble the peduncle 
of a species of Anomia (A. patelliformis), Lingula being likewise an 
aberrant form. 
Morse does not, however, fail to observe that “ in considering the 
assemblage of remarkable characters in the Brachiopoda, we must 
recognize in them a truly ancient type. Thus, while we do not find 
them in all their characters resembling any group of worms, 1 have 
endeavoured to show that all their features, to a greater or lesser 
degree, are shared by one or other of the various groups of the 
Yermes, with one or two features of the Arthropods.” 
Morse concludes bis elaborate series of observations by stating 
that he must regard the Brachiopoda as ancient ceplialized Clicetopods, 
while Serpula, Ampliitrite, Sabella, Protula, and others, may be 
regarded as modern (later) ceplialized Clicetopods. 
Mr. Dali, a distinguished American naturalist, is strongly opposed 
to the idea of placing the Brachiopoda among the Annelids, 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 com- 
parison between the Annelids and Brachiopoda, that these last are 
allied to the other groups included in the Molluscoida, and through 
their combined characters to the typical Mollusca. Stoliczka agrees 
with the conclusions advocated by Dali, and adds, “ There cannot 
be, I think, much doubt as to the true Molluscous character of the 
Brachiopoda, and their proper Classification between the Anomiidee 
of the Pelecypoda, and the Saccopoda, and the arm-bearing section 
of the Ciliopoda.” 1 
With such contradictory views as have here been briefly announced, 
it seems still premature to emit a positive opinion with respect to 
the affinities of the Brachiopoda, notwithstanding the mass of most 
valuable information so ably contributed to Science by Morse, 
Kowalevsky, Dali, and others. The following observations on the 
1 PalsEontologia Indica, Brachiopoda, vol. iv. 1872. 
