270 Systematic Paleoxtology 



twice the diameter of tliose in the intermaciilar spaces; zooccia thin-walled, 

 polygonal, 7 to 8 in 2 mm., counting from the center of a macula ; acan- 

 thopores not observed at the surface nor are they always present in thin 

 sections, remaining apparently undeveloped in certain periods of growth ; 

 in other sections from the same specimen, each angle of junction may be 

 occupied by one, and in some eases they attain considerable size as shown 

 in the figures. True mesopores apparently wanting, the occasional small 

 cells seen probably being young zocecia. Diaphragms occur in the tubes 

 at distances varying from one to two times their own diameter apart. 



This abundant species, in its growth and general characteristics, re- 

 sembles the Amplexopora petasiformis (jSTicholson) of the Cincinnati 

 Eden and the two Devonian species, Monticidipora ? monticula White of 

 the Hamilton of Iowa, and M. irinteri Xicholson, of Germany. Neither 

 of the two species last mentioned is known to have acanthopores, while the 

 Ordovician species has duplex walls. We know of no associated species 

 with which C. rotundata can be confounded. 



The species also occurs in the Lower Decker Ferry at Nearpass Quarry, 

 near Port Jervis, New York. 



Occurrence. — Helderbekg Formation, Keyser Member. Keyser, 

 West Virginia; Cash Valley, Pmto, Maryland. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Family BATOSTOMELLIDAE 



Genus BATOSTOMELLA Ulrich 



Batostomella ixterporosa n. sp. 



Plate XLV, Figs. 1, 2; Plate XLVIII, Fig. 5 



Description. — Zoarium ramose, branching at intervals, varying from 5 

 to 15 mm., branches cylindrical, 2 to 3 mm. in diameter; surface smooth, 

 the acanthopores in well-preserved specimens giving it a hirsute appear- 

 ance ; zooecia circular to slightly polygonal, 7 to 8 in 2 mm., generally 

 separated by a roAV of rounded mesopores variable in size ; acanthopores 

 numerous, usually about six surrounding a zocecium. Diaphragms ap- 

 parently wanting in both zoacia and mesopores. 



