KNTALOPHORID^R. 17 
The essential characters, as viewed by the writer, are given in the following description: 
Zoarium incrusting foreign bodies, the smooth shells of brachiopods or crinoid plates 
being usually favored. Growth commencing at a point from which the zooecia radiate. 
Zooecia contiguous, cylindrical, about 1 mm. in length and 0.22 mm. wide. Aperture cir- 
cular, slightly raised, about 0.20 mm. in diameter. Zooecia marked by delicate 1 transverse 
annular striations. 
The elongate, sharply defined, transversely lined zooecia form the important specific 
character and distinguish this beautiful species from other Paleozoic forms of the genus. 
Occurrence. — Wenlock limestone, Dudley, England (Lonsdale); Buildwas beds, Wenlock 
shales, Shropshire, England; Silurian, island of Gotland; Rochester shale, Rochester, Lock- 
port, and other localities in western hew York, and Grimsby, Ontario: Osgood beds, 
Osgood, Ind.; Waldron beds, Waldron, Ind., and Newsom, Tenn. 
Catalogue numbers, 35565, 35474, 44114, 44115, U. S. National Museum. 
Family KNTALO PHORIDyK Ren.-s*. 
Genus DIPLOCLEMA I Uriel.. 
Zoarium ramose, with tubular zooecia diverging on all sides from a wavy mesial lamina; 
apertures circular, prominent. 
DlPLOCLEMA SPARSUM (Hall). 
PI. V, figs. 6, 7; PI. XXIII, figs. 4-6. 
Trematopora sparsa Hall, Nat. Hist. New York, Pal. II, 1852, p. 15."), pi. 40A, figs. 12 a-d. 
Diplodema sparsa Ulrieh, Geol. Survey Illinois, VIII, 1890, p. 368, pi. 53, fig. 10. 
Diploclema sparsa Grabau, Bull. New York State Mus. Nat. Hist., No. 4.5, 1901, p. 162, fig. 57. 
The zoarium of this species is composed of small, subcylindrical ramulets, ovate in cross 
sections, about 0.5 mm. in width, 0.3 to 0.4 mm. in thickness, and dividing dichotomously 
at intervals of 10 mm. or more. The zooecia are thin walled, long, tubular, opening upon 
the surface with slightly protruding circular apertures, which, when well preserved, are 
surrounded by a peristome, 0.15 to 0.18 mm. in diameter; four zooecia in 2 mm. measuring 
longitudinally; a branch is formed of five or six linear series, adjacent series alternating. 
Interapertural space smooth or very faintly granulose. 
The widely separated rounded apertures and the small branches celluliferous on all sides 
readily distinguish this neat little species. Small fragments of Thamniscus dichotomus Hall 
might be confused, but the more closely distributed apertures and branches, celluliferous 
on one side only, distinguish that form superficially, the internal structure of the two being 
quite different. 
Diploclema sparsum has been considered by both Vine and Ulrieh to be closely related 
to Spiropora regular is Vine from the Wenlock of England, but a critical comparison of the 
American species with specimens of the latter received from Mr Vine shows the two forms 
to be specifically quite distinct. Diploclema (Spiropora) regularis forms more robust 
zoaria, the branches averaging almost 1 mm. in diameter, while measuring longitudinally 
two zooecia are found in 2 mm. The branches of Diploclema sparsum. as mentioned above, 
are 0.5 mm. in diameter and have four zooecia in 2 mm. 
Occurrence. — Rochester shale, Lockport, Rochester, Niagara Falls, and other localities 
in New York; Grimsby and Hamilton, Ontario. 
Catalogue numbers, 35734, 44071, U. S. National Museum. 
Diploclema sparsum var. argutum n. var. 
PI. V, figs. 8, 9. 
This subordinate name is proposed for the reception of a number of specimens which 
differ from Diploclema sparsum in the following respects: First, the zoarium is more robust, 
cylindrical, and bears four or five ranges of zooecia upon each side, while the typical form 
