422 PROCEEDINGS : BOSTON SOCIETY NATURAL HISTORY. 
including the epithecal prolongations. A carination runs along 
the length of the tube, but, owing to the twisting of the tube, it has 
a sinuous outline. The cross-section of the tube is roughly circular, 
there being no Rattening on the under side as in normal individuals. 
Except for the carination, this portion of the corallum is indistin¬ 
guishable from an attached corallum of C. distorta. The tube 
terminates in a normal upturned calyx, at the base of which two 
buds are given off. The left-hand bud is irregular, round in section, 
and much distorted. It is broken away near the base. The right- 
hand bud is normal, triangular in section, with a normal carina 
along the center, and lines of growth mostly sloping forward, 
though sometimes approximating those of C. distorta. The branch 
ends with a normal adolescent opening which, however, is some¬ 
what more vertical than in ordinary specimens. A notch in the 
right-hand lower margin of the opening indicates that the branch 
was about to give out buds. This normal branch is attached in 
places to the Taeniopora, showing below impressions of the surface 
features of the bryozoan. Taken in connection with the abnormal 
specimen of C. distorta , PI. 3, figs. 9, 10, which shows characters 
of C. dichotoma , the close relation of the two species becomes well 
established. 
Formation and localities. This species is common in the soft 
Hamilton shales of Eighteen Mile Creek and vicinity in western 
New York. It there occurs in the lower Moscow and the upper 
portion of the lower shales. The specimens usually occur on the 
lower surface of the shale laminae, their calices deeply embedded 
in the shale, and only the fiat lower portion exposed (PI. 4, fig. 1). 
The species also occurs in limestones of the Hamilton group at 
Canandaigua Lake. It occurs here in a silicified condition, and 
shows many structural details. The specimens from Eighteen Mile 
Creek were collected by the author, those from Canandaigua Lake 
bv Prof. C. E. Beecher. 
General Observations. 
The general form and manner of budding in the various species 
described form a pretty reliable index to the manner of growth in 
each. The three species of Monilopora, when not attached to foreign 
objects of support (i. e. crinoid stems), grew erect and unsupported, 
