172 
BULLETIN OF THE LABORATORIES 
XIX. Monotrypella confluens, sp. n. 
(Flafe XVI, Fig. 4; Plate XVII, Fig 15.) 
Zoaria irregularly ramose, branches varying from 5 mm. to ii 
mm. in diameter, usually forming coarse, gnarled growths by the irreg- 
ular confluence of several branches, which are very characteristic of 
this species. Cells vary from 9 to ii in a distance of 3 mm; where 
the surface is well preserved, the margins of the cells are seen to be 
circular and to be distinctly raised above the surface of the branch. 
The margins sometimes touch each other on one or more sides, but 
are just as frequently entirely free and distinct, and never are polygon- 
ally compressed. The interstitial spaces left between the raised mar- 
gins of the cells sometimes have the appearance of small interstitial 
cells, but usually they appear simply as depressed areas. In worn 
specimens the raised margins of the cells can not be detected and the 
inter-cellular spaces then appear simply as thickened cell walls, sepa- 
rating. the cells. Tangential sections give no evidence of interstitial 
cells in such cases, and in longitudinal sections the cells appear to be 
of one kind only. The cell walls in tangential sections near the sur- 
face appear very thick, but only a slight distance from the surface they 
are seen to be very thin. Straight diaphragms are developed in mod- 
erate numbers and are- somewhat more numerous towards the surface, 
but the distinction between the mature and immature portion does not 
seem to be very great. About 9 diaphragms occur in one of the sec- 
tions in a distance of 3 mm ; the number naturally would vary consid- 
erably however. In some specimens in which the surface is free from 
all sediment, operculate diaphragms seems to extend across the cells a 
short distance below the surface of the specimen. Some specimens 
also show low elevations about 3 mm. distant from each other, in 
which the number of cells seems somewhat reduced. The name re- 
fers to the characteristic gnarled expansions formed apparently by the 
growing together of branches, the latter becoming confluent. 
Locality and position. Soldiers’ Home, Clinton Group. 
Genus CALLOPORA, Hall. 
“ Ramose to sub-frondescent, smooth or tuberculated. Cell-tubes 
cylindrical, their apertures often closed by an operculum, with a very 
small central perforation, from which usually radiate small ridges. In- 
