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THE AMERICAN NATURALIST [Vol. XLIII 



as far east as Kurrachee, and says that it "is not known to 

 extend further eastwards," and I know of no subsequent addi- 

 tions to its range; Mr. Chadwick did not give it from Ceylon 

 in his list of the crinoids of that island published in 1904. 



In the introductory paragraph Mr. Chadwick mentions the 

 interesting fact that none of the Comasteridae are known from 

 the Red Sea. They probably occur there, however, and will 

 eventually be discovered when more extended work is under- 

 taken. The absence of any species of Zygometridas is note- 

 worthy, arid also that of Himerometra, one species of which, 

 H. persica, was first described from the Persian Gulf and sub- 

 sequently found in the Philippines. He also takes occasion to 

 point out a weakness in Dr. F. A. Bather's argument for the 

 treatment of a syzygial pair of brachials as two single brachials 

 united by syzygy, instead of a single brachial "with a syzygy," 

 the treatment adopted by Carpenter and Hartlaub. Mr. Chad- 

 wick's contention is that if the two brachials united by syzygy 

 were originally, as urged by Dr. Bather, united by the ordinary 

 oblique muscular articulation of the distal portion of the arm, 

 which oblique muscular articulation had been transformed into 

 a syzygy at the same time dropping its pinnule, the pinnule upon 

 the resultant epizygal would be upon the same side as that upon 

 the joint preceding the hypozygal, instead of on the opposite side, 

 as is always the case. Mr. Chadwick is inclined to believe that 

 this is evidence in favor of the views of Hartlaub and Carpenter, 

 and against the ideas of Dr. Bather. I maintain that the 

 syzygial pair is the morphological equivalent, not of one joint as 

 urged by Carpenter (in part) and Hartlaub, nor of two joints 

 as supposed by Dr. Bather and apparently considered by Pro- 

 fessor Perrier, but of three joints, the central one of which has 

 dwindled and disappeared, so that the oblique muscular articula- 

 tions on its proximal and distal ends have become superposed, 

 their ligaments, being dominant over their muscles, fusne- and 

 forming the radiating figure which is the original of the later 

 more periected syzygy. while the muscles, and with them the 

 pinnule sockets (borne by the muscular fossa.) have disappeared. 



Thus the syzygy originally, instead of ] 



. supposed by Dr. Bather, had two, which" ^t^d^d^tt 

 * that the syzygy in its perfected form has no effect on tl 

 "' ma i 1 ". n ' , Austin Hobart Clark. 



