ON FOSSIL SPONGES FEOM METIS. 43 



from the Utica shale, but diliers iu detail, especially iu simplicity of the vertical rods 

 and development of the transverse or circular bars. The largest specimens are 8 cm. long 

 by 3 wide at top. There are signs of minute lateral defensive spicules. The general 

 form and structure resemble those of the modern sponges of the genus Holascus. 



The species Cyathophijcus reliculalus was founded by Walcott on specimens from the 

 Utica shale, but, as it has not been thoroughly described, the following notes, for much of 

 the material of which I am indebted to Dr. Hinde, may be useful : — 



In the collection of minerals of the late Mr. J. S. Miller of Ottawa, purchased for 

 McGrill University, are a few fossils, some of them Canadian, others from the phosphate 

 deposits of South Carolina. Among the former are a few specimens of Utica slate fossils, 

 which, from their appearance I suppose to have been collected in the beds of that forma- 

 tion near Ottawa, though it is possible that some of them may have been obtained from 

 the United States. They include a specimen of the above species, which Mr. Ami, who 

 has collected extensively iu these beds at Ottawa, informs me has not yet occurred to 

 him. The specimen is a small slab of the ordinary Utica shale, having an impression of 

 a glabella of Triarthrus on the back, which jiroves its geological horizon. It has two 

 specimens of Cyathophycus close together, nearly perfect at their bases and broken off at 

 the height of about three inches. They are perfectly flattened and pyritised, which is also 

 the condition of other fossils in these shales, with the exception of the graptolites, which 

 seem to have resisted this kind of change. 



The genus Gyathophycus was originally described by Walcott from specimens obtained 

 at Trenton, Oneida Co., New York.' He regarded it as an alga, whence the termination 

 -phycus ; but subsequently, in the ' American Journal of Science,' 1881, corrected this error, 

 and referred it to the sponges. Hall (o5th Regents' Report) properly places it with the 

 reticulate sponges included in his family Dictyospongidcc, but does not add much to 

 Walcott's original description, to which the present specimens permit some additions to 

 be made. 



The specimens are perfectly flattened, biit show distinct indications of the two sides 

 of the originally conical form. The wall of the skeleton has evidently been thin and 

 composed of slender bundles, each of a few long simple spicules, and increasing both by 

 bifurcation and the introduction of new bundles, so as to j)reserve nearly the same dis- 

 tances in the wider parts of the cone. They are very regular in the lower part, where 

 there are about nine principal, with some intermediate secondary bundles in a centimetre, 

 but they become more irregular toward the top. This may, however, be an effect of 

 decay and crushing. At the base these bundles become thicker, and in a specimen from 

 the original New York locality, kindly lent to me by Mr. Ami, I have observed that they 

 become expanded and converted into somewhat short clavate root spicules. This is, 

 however, not apparent in Mr. Miller's specimens, which may have been broken off at the 

 surface of the mud. 



The vertical bundles are crossed at right angles by horizontal spicules much less 

 regularly arranged, but dividing the surface into rectangular meshes. These are slightly 

 oblique and rhomboidal iu the specimens, but this is probably due to pressure. The 



' Traus. Albany Instit., 1870. 



