180 THE DEVONIAN OF MISSOURI. 



"Diameter of corallum 5 to 10 mm. Diameter of orifices varying with maturity of 

 corallite from 1 to 2.5 mm. 



"This species differs from 5. issa Hall in its less conical calyx with less prominent 

 furrows. It differs from S. cavernosa Rom. which has more funnel-like calyces with 

 obtuse edges." — Swartz, 1913. 



Dimensions — Mean diameter of branches 6.5 to about 13.5 mm. Range in greatest 

 diameter of corallites of the various specimens, and maximum range for any one speci- 

 men 0.8 to 3.5 mm. 



Genus Pleurodictyum Goldfuss 



Pleurodictyum lenticulare (Hall) ? 

 Plate 42, figure 9 

 Michelinia lenticularis Hall, 1874. 26th Ann. Rept. N. Y. State M us. Nat. Hist. p. 113. 

 Michelinia lenticularis Hall, 1879, 32nd Ann. Rept. N. Y. State Mus. Nat. Hist. p. 145. 

 Michelinia lenticularis Hall, 1883, Rept. State Geol. N. Y. for 1882, pi. Ill, figs. 1-3, 5. 

 Michelinia lenticularis Hall, 1887, Pal. N. Y., vol. VI, p. 7, pi. Ill, figs. 1-3, 5. 

 Pleurodictyum lenticulare Beecher, 1891, Trans. Conn., Acad. vol. VIII, p. 207. 

 Pleurodictyum lenticulare Girty, 1895, 48th Ann. Rept. N. Y. State Mus. Nat. Hist., 



vol. II, p. 305. 

 Pleurodictyum lenticulare Swartz, 1913, Md. Geol. Surv., L. Dev., p. 218, pi. XXVI, 



fig. 1. 



Description — "Corallum forming small lenticular bodies, the lower surface usually 

 the less convex and covered with a strongly wrinkled epitheca. Cells large and few, 

 usually from seven to twelve; broadly campanulate. Partition walls about 1 mm. thick; 

 strongly marked longitudinally by nodose striations; denticulate on the margins. The 

 number of striations and denticulations varies with the size of the cell. 



"In a characteristic specimen 20 mm. in diameter, there are eight cells, the central 

 one having a diameter of 11 mm., and the peripheral cells measuring from 6 to 8 mm. 

 across. The entire height of this specimen is 9 mm. 



"[Remarks] — This is a very small species, seldom attaining a diameter, of more 

 than 25 mm., and is distinguished by its large cells and their strongly granulose-striate 

 character. A small individual 10 mm. in diameter shows one large central cell and six 

 smaller ones around the margin, also an incipient seventh cell. Occasionally there are 

 two central cells in large individuals, and the number of peripheral cells in such speci- 

 mens is from ten to twelve." — Hall, 1887. 



Dimensions — Diameter of corallum undeterminable. 



Remarks — On a fragment of rock are two detached groups of corallites which 

 probably are parts of one corallum; one group shows portions of nine corallites, the 

 other of four corallites. The nature of the base of the corallum represented is unde- 

 terminable. 



ECHINODERMATA 



Class CRINOIDEA 



Order Camerata 



Family Melocrinidae 



Genus Scyphocrinus Zenker 



Scyphocrinus sp. 



Plate 42, figure 10; plate 43, figures 1-6 



Description — This genus is represented by several parts of calyces and root-bulbs 



that are provisionally regarded as of a single species. 1 



l The "inflated or bulbous root" of Scyphocrinus was described as Camarocrinus by Hall 

 and as Lobolithus by Barrande. See von Zittel's Text-book of Pal., vol. I, pp. 160 and 190, 

 1913. 



