1881.] NATURAL SCIENCES OF PHILADELPHIA. 225 



slight modifications in ornamentation; while still others were 

 founded upon material so imperfect that neither figure nor de- 

 scription suflflciently defines the form. Our literature is so over- 

 burdened with S3'non3'ms that we fear a veiy large percentage of 

 so-called species ought to be eliminated. We have undertaken to 

 point out such cases among the Burlington and Keokuk Crinoids, 

 and although we have been obliged to throw out a considerable 

 number of species, we have only done so where necessity seemed 

 to require it, and we suspect we should not have gone amiss by 

 reducing the list still more. Schultze undertook the same task 

 for the Crinoids of the Eifel, and, although we cannot agree with 

 him in retiring certain genera, we concur in his determination of 

 synonymic species. There are no doubt, also many synonyms 

 among the Subcarboniferous Crinoids of Belgium and England. 

 One of us had an opportunity, several years ago, of studying the 

 original collection of De Koninck in the Museum of Cambridge, 

 and became convinced that the eleven Belgian species of Actino- 

 crinus. described in the Recherches Crin. Carb. Belg., might be 

 safely reduced to four or five. 



10. The SO-CALLED "Respiratory Pores." 



In the first part of this work, on page 11, we called attention 

 to certain pores, located in the body at the arm regions, on either 

 side of the ambulacral openings, and we endeavored to show that 

 they correspond in position with the so-called ovarian openings 

 of the Blastoids. At that time we asserted that the pores were 

 in some genera fixed at a definite number, independent of the 

 number of arms in the species; that Batocrinus, for instance, had 

 alwaj'S twenty pores, whether the species had twenty arms or 

 more, and that one-half the pores were located radially and the 

 rest interradially. In this we were evidently in error ; the pores 

 probably alwaj's agree in number with the arms, and are really 

 neither radial nor interradial, but are placed at the base of the 

 arras. A specimen of Batocrinus subaequalis, now before us, with 

 twenty -two arm openings, has twenty-two pores, and a specimen 

 with twenty -four arms has twentj-four pores. In the former the 

 vault became accidentally detached from the calyx, in such a 

 manner, that we were enabled to follow up in both parts the direc- 

 tion of the pores as they pass into the body (PI. XIX, fig. 4). 

 Neither the pores nor the arm openings penetrate the plates, but 



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