INDIANA PALEONTOLOGY. m. 



not be doubted and its origin is not due to an elastic integument, even though the latter may be 

 capable of a good deal of stretching. We have seen it on specimens of Pentremites godoni from 

 Kentucky and Tennessee, and Etheridge and Carpenter figure a specimen of P. sulcatus showing 

 a ventral covering on plate I, in the "Catalogue of the Blastoideae." These same authors on 

 plates III and VI have drawings of specimens of Sehizoblasiu.s sayi. and on VI and VII of Orbitre- 

 mites norwoodi showing Qlosed summits. On plate XV of the same work are similar figures of 

 Orophocrinns steUiformis. 



Meek and Worthen in the Fifth Illinois Report also figure the latter species with a ventral 

 covering. 



Try as hard as Dr. Hambaeh and others have done to separate the Blastoids and Ci-inoids as 

 far as possible, the fact is patent to the unbiased observer that they have many homologous 

 parts. Both were stalked, both had basals, radials, interradials, covered ventral disks, (the 

 latter reduced to a minimum in blastoids) pinulae and arms, if the ambulacra of the Blast oidese 

 represent recumbent arms, respiratory pores around the arm bases and an anal opening through the 

 test or on the end of a proboscis. The Doctor may be in error when he says he believes organs simi- 

 lar to the anal tube of Pentremites conoideus existed in all typical species, for we might rush to the 

 same conclusion on beholding for the first time the proboscis of Actinocrinus. We imagine similar 

 conditions will be found to occur in the genera of Blastoids. Some will have probosces and others 

 mere openings through the test. 



It would be much safer to say, and we are willing to make the unqualified statement, that all 

 blastoids in life had a ventral covering of small plates. 



Dr. Hambachs statement that his hypothetical water vascular duct in a state of collapse has 

 given rise to the assertion that there is an under lancet piece, and his further statement that "his 

 much doubted tentacles, protruding through the poral openings" have formed in their collapsed con- 

 dition "the supplimentary poral pieces of Dr. Roemer or outer side plates of later authors" are not 

 any nearer acceptance than they were years ago. for his present paper is little more than a rehash 

 of the earlier one. 



To put beyond dispute the character of certain small tubes lying between the hydrospiric folds, 

 our reviewer has actually found petrified ova in them. It only remains to establish beyond question 

 the function of certain other vessels by the discovery of petrified water in the ducts. It is reasonable 

 to suppose now that the little ovulum-like bodies that Dr. Hambaeh found resting in the central 

 summit orifice were not drifted in by the water but were actually fresh laid eggs. 



After reviewing the earlier classification and pointing out its inadequacy to present need in view 

 of the increased knowledge of the subject and the better understanding of the relationship of the 

 parts, the author proposes a new classification based upon the summit openings, development of the 

 deltoids and the aspect of the outer surface, remarking. '-Xor can we attribute any more than specific 

 value to the hydrospiric tubes, or plications, on account of the variability often observed in one and 

 the same specimen, a fact sufficiently recognized by the very authors who regard them as being of 

 importance for classification." and we are actually treated to views of three specimens of as many 

 species with deformed hydrospires, but the author neglected to tell us how many speciraens with the 

 normal number of folds he examined before he found the abnormal ones. 



Does he know that there is some variation even in the spiracles of a single individual"? Etheridge 

 <fe Carpenter on plate VII of "The Catalogue of the Blastoidea" in figure 12 show a double spiracle 

 in one of the deltoids of 0. noricoodi. 



