78 THE PALEONTOLOGY OF MINNESOTA. 
[Heterospongi 
CYLINDROC@LIA MINNESOTENSIS Ulrich. 
PLATE G, FIGS. 1-3. 
1889. Cylindrocelia minnesolensis ULRICH. American Geologist, vol. ili, p. 248. 
Original description —‘ This species differs from the preceding ones | C. endoceroidea, 
C. covingtonensis| in being almost perfectly cylinderical (7..e. allowing for a slight 
amount of compression apparent in all the specimens), the average taper in a length 
of 40 mm. being rarely more than 1 mm. Most of the fragments vary in diameter 
between 10 and 15 mm., but it is sometimes a mm. more or less. . Basal extremity 
not satisfactorily shown in any of the specimens; apparently truncate. The cloaca 
must have been narrow since it, like the internal portion of the canal system, has 
in every case been entirely obliterated by the crystallization of the calcite of which 
the specimens are composed. The surface is smooth and may, according as the der- 
mal layer remained or had been removed at the time of fossilization, exhibit very 
few or comparatively abundant canal apertures—more irregularly distributed, how- 
ever, and not nearly so numerous as in the other species. The canals are rounded 
and vary in diameter from less than 1 to 2.5 mm.” 
Formation and locality.—Rare in the Trenton shales at Minneapolis, St. Paul, and Fountain, Minne- 
sota. Occurring also at the base of the Galena shales, six miles south of Cannon Falls, Minnesota. 
Collectors.—E. O. Ulrich and W. H. Scofield. 
Mus. Fieg, No. 7709. 
HETEROSPONGIA, Ulrich. bs 
1889. Heterospongia, ULRicH. American Geologist, vol. iii, p. 239. 
1891. Heterospongia, JAMES. Jour. Cincinnati Soc. Nat. Hist., vol. xiv, p. 71. 
Original description— “Sponges consisting of sublobate or irregularly divided 
compressed branches. Entire surface exhibiting the mouths of branching and more 
or less tortuous canals, which begin near the center, where they are nearly vertical, 
and proceed toward all portions of the surface in a curved direction. A limited num- 
ber of oscula, distinguished from the ordinary canals by being larger and surrounded 
by radiating channels, occasionally present. 
‘Sponge skeleton between the canals of variable thickness, sometimes appearing 
nearly solid, at other times composed of loosely interwoven spicule fibers. None of 
the specimens show the spicules in a satisfactory manner. From the traces seen it 
would appear that they are mostly very small and of the three-rayed type. 
“Type, H. subramosa Ulrich.” 
