Maryland Geological Survey 271 



The numerous mcsopores opening at the surface distinguish this species 

 particularly. Externally the species suggests Lioclema, but thin sections 

 readily establish the generic position. 



Occurrence. — Helderberg Foriiatiox, Keyser Member. Devil's 

 Backbone. 



Collections. — Maryland Geological Survey, D". S. National Museum. 



Genus CALLOTRYPA Hall 



Callotrypa striata (Hall and Simpson) 



Plate L, Figs. 5-8 



Callopora (Callotrypa) striata Hall and Simpson, 1887, Pal. N. Y., vol. vi, p. 

 26, pi. xi, figs. 38-41; pi. xxiii, figs. 13, 14. 



Description. — This small, solid, ramose species may be readily dis- 

 tinguished from all associated bryozoa by the abundant mesopores, sepa- 

 rating the oval apertures and by the prominent spines at the base of each 

 aperture. Frequently the mesopores are elongated and so disposed that 

 they give a finely striated appearance to the surface. The zooecial aper- 

 tures average .17 of a mm. in length with a width about three-fourths the 

 length. 



Occurrence. — Helderberg Formation, New Scotland Member. 

 North foot Moore Knob. 



Collection. — U. S. National Museum. 



Callotrypa macropora (Hall) 

 Plate L, Figs. 9, 10 



Callopora macropora Hall, 1883 (in part), Rept. State Geol. N. Y., pi. xi, 



figs. 23-29. 

 Callopora {Callotrypa) macropora Hall and Simpson, 1887, Pal. N. Y., vol. vi, 



p. 24, pL xi, flgs. 25-29; pi. xxiii, figs. 15-19. 

 Callotrypa macropora Simpson, 1897, 14th Ann. Rept. State Geol. N. Y. for 



the year 1894, pL xviii, figs. 12-14. 



Descripiion. — Zoarium of solid, ramose, frequently bifurcating 

 branches, varying from 1 to 2 mm. in diameter. Zooecial apertures polyg- 

 onal, rather thick-walled, 5 to G in 2 mm. Mesopores small and irregu- 

 larly distributed. 



