J94. CONTRIBUTION TO 



xxviii, figures 15 and 16, both papers antedating the learned professor's publication by several 

 years. 



Dr. F. A. Bather in ''The Record of and Index to the Literature of Echinodermata" for the 

 year 1900, at the bottom of page 49, mentions our discovery of the blastoid anal tube. 



It seems to us that the figures on plate I of Dr. Hambach's paper, show merely the results 

 of injury to the ambulacra, just what one would expect to see in some specimens, but carrying 

 no evidences of a flexible membrane. 



With a persistance that is remarkable and with almost all of the most accurate observers 

 against him, the Doctor still denies the existence of a roof of small plates covering the central 

 opening of Pentremites and allied forms, arguing that it "is only logical to suppose that, if nat- 

 ure provided an opening it should remain open or that the covering is a flexible one and not 

 formed by additional plates inserted into the openings as intimated by all authors who adopted 

 the first statement of Shumard," and yet in his diagnosis of the genus Olivanites, he says "Cen- 

 ter of the summit closed by additional pieces" (See page 49 of his paperj. Did nature so far 

 forget herself as to make a central summit opening in Nucleocrinus and then roof it over with a 

 covering of plates ? 



I have seen dozens of specimens of Nucleocrinus verneuili withtho ventral covering in place . 

 In fact most of the specimens found at the Falls of the Ohio are in that condition as I infer from 

 the material of Mr. <J. K. Greene that has passed through my hands. Not verneuili alone, either, 

 as I have seen the covering also on angularis, greenei and venustus. 



The statement that "every one disregards the fact that all casts of the interior of a calyx 

 exhibit on the summit a cast of the summit opening" is a great mistake of the Doctor's if he in- 

 cludes Schizohlastus sayi in the statement and I am led to believe he does, since in his diagnosis 

 of Cribroblastus he uses these words, "Central opening never closed except by ambulacral in- 

 tegument." 



There is little doubt that his vast collection is deficient in structural material outside of 

 Pentremites or he would not commit himself to such a statement. 



I have collected hundreds of casts of sayi and a vast majority of them are specimens with a 

 closed summit. 



Of my specimens of the same species preserving the test, and I have fifty or more from Lou- 

 isiana alone, less than one tenth are without the ventral covering or roof of small plates over the 

 central area that Dr. Hambach would leave uncovered in defference to nature. 



Of the rare species Lopliohlastiis inopinatiis we have two specimens preserving the ventral 

 covering, two of L. aplatus. one of L. marginulus and several among other species. 



In one specimen of Orophocrinus stelliformis in our collection not only the ventral covering 

 is in place but a roofing of small plates has extended down each ambulacrum, broken in more or 

 less, in four of the ambulacra, but preserved to the distal end of the fifth. 



These coverings that we have seen are made up of small plates not foreign matter or ovulum- 

 like bodies drifted into the orifice and mistaken for plates, for where the roofing extends over the 

 ambulacrum there is a neatly arched canal beneath. 



That a pyramidal covering is occasionally found over the central orifice of Pentremites can. 



