898 on. F. A. BATHER ON 



CRINOIDEA DICYCLICA INADUNATA. 



Suborder CYATHOCRINOIDEA. 



Dr. Frank Springer, in his paper on " Some new American 

 Fossil Crinoids " (July 1911, Mem. Mus. Comp. Zool. Harvard, 

 vol. XXV. no. 3), has pviblished a very interesting discussion of 

 my Suborders Cyathocrinoidea and Dendrocrinoidea. While 

 differing as to the delimitation of these divisions and the 

 principles upon which they are based, he readily agrees in 

 recognizing their existence. He prefers to regard theni only as 

 large Families, to which he applies the names Cyathocrinidse and 

 Poceriocrinidte, but admits that this is "a matter of detail, 

 depeiuling upon the general plan of treatment." It was necessary 

 for me to treat them either as Suboi'ders or Superfamilies, because 

 1 split them up into Families, several of which are again divided 

 into Subfamilies. I am, therefore, emboldened to i-etain for the 

 present the Suborder Cyathocrinoidea. 



Family Gasterocomidae. 



Cyathocrinoidea, with anal opening in the side of the dorsal 

 cup, below the level of the arm-bases. Radial facets of horse- 

 shoe shape, with distinct axial canal. Infrabasals small, often 

 fused into three plates or one. Oi'als, so far as known, for the 

 most part concealed by the cover-plates of the subvective system ; 

 posterior oral a lurge madreporite. Stem frequently with peri- 

 phei^al canals. 



Dr. Springer, in the above-quoted memoir (July 1911, p. 122), 

 has given a full account of the Gasterocomidse, although he has not 

 provided any fresh diagnosis. The characters which he mentions 

 as distinctive are included in the above diagnosis, which differs 

 only verbally from that published by me in Lankester's ' Treatise 

 on Zoology ' (Part iii. 1900, p. 177). Dr. Springer further agrees 

 Avith Jaekel and with me in referring to the Family the genera 

 Gasteroco7na, A^anocrinus, Scoliocrinus, and Achi'adocrinus. To 

 these he adds a new genus, Schidtzicrinus, found in the Onondaga 

 Group of the Middle Devonian in Livingston County, New York. 

 This genus has the infrabasals coalesced and five simple uniserial 

 arms. Further, Dr. Springer adds Arachnocrinus Meek and 

 Worthen, of which he has made a complete study, showing that 

 our previous views as to the structure, and therefore as to its 

 systematic position, were erroneous. This genus differs from 

 Schultzicrinais mainly in having dichotomous arms. I am, of 

 course, jjrepared to accept its reference to the Gasterocomidse. 



Apparently, Dr. Spi'inger would also place in the Gasterocomidse 

 the genus Myrtillocrimis Sandberger, of which he considers Tri- 

 jtleurocrinus E. Wood to be a synonym. In this he follows 

 Wachsmuth and Springer (' Revision of the Palpeocrinoidea,' 1885), 

 as well as some other writers therein quoted. It may, however, 



