The Corals of Delafield. 191 



present classed under the old genus because they have not been 

 proved to belong to any other genus, i, e., their manner of growth 

 has never been discovered. 



C. airitus, the first foi^m noted under this designation, was tirst 

 described in the Ohio reports. It is distinguished by the presence 

 of small quadrangular, conical eminences, which are thickly 

 scattered over the surface of the coral, especially at the flattened 

 ends of the branches. The specimens from Ohio are described as 

 cylindrical, frequently branching forms, from four to seven lines 

 in diameter and eight to ten corallites in the space of one line. 

 Ours are much smaller, from one and a half to three lines in 

 diameter and flattened, with ten or twelve corallites in the space 

 of a line. Chceietes Jamesi, described likewise in the Ohio re- 

 ports, has it3 representative here also. The walls of the corallite 

 cells in this form show the extraordinary thickness exhibited by 

 the Ohio form, but also show a well marked groove upon their 

 summit, a feature that is not noticed by Nicholson in his descrip- 

 tions, nor shown in a type specimen which I have examined from 

 that state. This feature has been before mentioned as a charac 

 teristic of the Bryozoan genus Trematopora. C. fusiforviis is a 

 new species (see An. Eep't, '76, p. 70). This is a very minute 

 form, less than an inch in length and an eighth of an inch in 

 diameter. The cells are very minute, twelve to twenty in the 

 space of a line. The cell walls are thick, sometimes with minute 

 pores, sometimes with a well marked groove on their summits, 

 and in other cases sharply ridged between the cells. The very 

 close resemblance that exists between this form and Trematopora 

 annulifera argues very strongly against their being placed in dif- 

 ferent sub-kingdoms. I have failed to find any characteristic in 

 these two last species that should remove them from those of the 

 genus Tremaiopjora. 



I desire also to call attention to some undescribed and perhaps 

 previously unnoticed forms which I observed while classifying 

 the collections of the state survey. 



The first is a thin expansion found encrusting a fragment of a 

 Brachiopod shell. The cells in this form are rather larger than 

 those of any of the other species here noted, and seemed to be 



