226 SYSTEMATIC PALEONTOLOGY 



Family PHYLLOPORINIDAE 



Genus GHASMATOPORA Eichwald 



CHASMATOPORA EETICULATA (Hall) 



Plate XL, Pigs. 4-6 



Intricaria f reticulata Hall, 1847, Pal. New York, vol. i, p. 77, pi. xxvi, 



figs. 8a-c. 

 Phylloporina reticulata Ulrich, 1890, Geol. Surv. Illinois, vol. viii, pp. 332, 



639, pi. liii, figs. 2, 2a. 

 Phylloporina reticulata Ulrich, 1893, Geol. Minnesota, vol. viii, p. 210, pi. iv, 



figs. 8-15. 

 Chasmatopora reticulata Bassler, 1911, Bull. U. S. Nat. Mus., No. 77, pp. 170, 



171, text fig. 86. 



Description. " Specimens as seen, consisting of small, flat or undulat- 

 ing, reticulate expansions, being in each case evidently fragments of a 

 depressed, funnel-shaped zoarium, probably not exceeding 5 cm. in 

 diameter. Branches rounded in section, 0.2 to 0.3 mm. in diameter, 

 inosculating at unusually frequent and regular intervals. Fenestrules 

 somewhat elongate, about as wide as the branches, subrhomboidal in 

 shape in the more regularly constructed fragments; their number in a 

 given space is fairly constant, the extremes noticed in 1 cm. being 10 

 and 12. Reverse of branches convex finely striated lengthwise. 



" Obverse strongly convex, with three rather irregular rows of zooecia, 

 their apertures subcircular, with a distinct peristome, about 0.1 mm. in 

 diameter, eight or nine in 2 mm. Acanthopores abundant, irregularly 

 distributed, rather large, especially so in the earliest forms of the species. 

 Interspaces slightly concave, occasionally faintly pitted and striated. 



" In tangential sections the zooecia are rather short, with a row on 

 each side directed obliquely outward, and one series between them. The 

 latter are wedge-shaped, and in deep sections appear as a more or less 

 narrow central space. Diaphragms, one in each tube, have been observed." 

 Ulrich, 1893. 



Occurrence. CHAMBERSBURG LIMESTONE (Caryocystites bed). Fort 

 Loudon and Blue Spring, Franklin County, Pennsylvania. The original 

 types are from the Trenton limestone of New York, but the species has a 

 wide distribution in both the Black River and Trenton rocks. 



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



