CAMBRO-SILURIAN MICRO-PALEONTOLOGY. 47 



" Segments club-shaped, varying in length from less than one milli- 

 metre to nearly two mm. ; lower half sub-cylindrical, about 0'23 mm. in 

 diameter, non-celluliferous, covered with fine, granulose, vertical striae ; 

 lower extremity bulbous, smooth ; upper half celluliferous, expanding 

 more or less rapid I3", the depressed conical top varying in diameter 

 from 0*7 to two mm. The apertures of the zonecia on the top are sub- 

 circulai-; about 0*09 mm. in diameter and arranged in radial series 

 between raised lines about the large central socket. A« the zoarium 

 expands the series increase in number by interpolation. The apertures 

 of the zocpcia on the sides are ovate and a little larger, having an 

 average length of Oil mm. Like those on the top, they are ari-anged 

 between elevated granulose ridges." 



Detached segments of this very pretty little bryozoan are abundantly 

 strewn overthesurfaceof some of the slabs from Stony Mountain, Mani- 

 toba, and I do not doubt that if searched for, specimens preserving a 

 number of them joined together would be found there. Such must be 

 looked for in shaly layers only. Among the specimens from Savannah, 

 111., there is one consisting of two segments still joined together. 

 Those from Wilmington, 111., consist of isolated segments. Hero they 

 iire neither abundant nor easily detected, being readily overlooked 

 because of their small size and the peculiar charactei' of the rock. 



Nematopora (?) (N. Sp.)* 



A fragment of what appears to be an undescribtd species of this 

 genus adheres to a small slab collected at Stony Mountain by Mr. T. C. 

 Weston in 1884. It is five-sided and distinguished from all the species 

 known to me in having the thin raised line bordering the two sides of 

 the narrowly elliptical apertures of the zooecia continuous fiom aper- 

 ture to aperture. In the space between the ends of the mouths of the 

 zooecia these lines approach each other but do not unite, a narrow 

 channel being left. I wish to see more specimens before proposing a 

 specific name. 



Phylloporina Trentonensis, Nicholson. 



Retepora Trentonensis, Nicholson. 1875. Pal. of the Province of Ontario, p. 15, 



pi. 2, figs. 4-46. 

 Whiteaves. 1881, Geol. and Nat. Hist. Sur. Can., Rep. 

 Prog. 1879-80,' p. 58 c. 

 Phylloporina trentonensis, Ulrich. Rep'ts. Ill Geol. Sur., vol. 8, pi. 53, fig. 1-lc. 



♦This genus is proposed in vol. 8 of the Report of the Illinois Geological Survey (in press) 

 for species of the type of Helopora lineata, Billings. 



