. The Devonian crinoids of the State of New York. Crinoidea, Fossil; Paleontology; Paleontology. DEVONIAN CRINOIDS OF NEW YORK 243 The number of interbrachials in Dorycrinus is limited, being rarely more than three in the dorsal cup, the two upper ones at the level of the arm bases. They are more numerous in Thamnocrinus, the species springeri having six rows of interbrachials up to the terti- brachs and a number of small irregularly arranged ones beyond that point. The anus is excentric in Dorycrinus and opens high up in the teg- men. Both genera bear spines on the tegmen —-in Dorycrinus the
. The Devonian crinoids of the State of New York. Crinoidea, Fossil; Paleontology; Paleontology. DEVONIAN CRINOIDS OF NEW YORK 243 The number of interbrachials in Dorycrinus is limited, being rarely more than three in the dorsal cup, the two upper ones at the level of the arm bases. They are more numerous in Thamnocrinus, the species springeri having six rows of interbrachials up to the terti- brachs and a number of small irregularly arranged ones beyond that point. The anus is excentric in Dorycrinus and opens high up in the teg- men. Both genera bear spines on the tegmen —-in Dorycrinus the posterior oral and frequently the first radial plates above the ambulacra bear spines; in Thamnocrinus there are sixteen spines, one sub- central and situated just above the anal opening, the others disposed three to the ray. In Dorycrinus the arms are in groups, rather short, two to four arms to a ray, and more or less spinous; in Thamnocrinus the arms are long and not spinous. There are two main arm trunks to each ray, short, uniserial and very heavy, which divide (four times) by unilateral heterotomy, the un- divided branches being given off to the inside. The Column in both is round, Figure 48 Analysis of calyx of Thamnocr: -r^. • 1 11 springeri, the genotvpe. m Dorycrinus having a small pentangular axial canal, in Thamnocrinus a fairly large round 1 n u s Thamnocrinus springeri sp. nov. Plate 26, figures 8-10; text figure 48 This handsome species is represented in the collections of the New York State Museum by two splendid specimens. One lying on a block of lime- stone shows the dorsal cup and the lower portion of the arms. Originally there were some 65 mm of column attached, but most of this has been. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Goldring, Winifred, 1888-1971. Albany : Uni
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectpaleont, bookyear1923
