8o LOWER PENINSULA. 



in loose, irregularly reticulated colonies, with the curved stems alter- 

 nately contiguous and diverging. Transverse connecting channels 

 remote, short, and clumsy. Longitudinal rows of spinules and fun- 

 nel-shaped diaphragms, quite plainly exhibited in some of the 

 specimens. I have not figured this form for want of space. 



SYRINGOPORA ANNULATA, N. Sp. 



Small colonies of closely approximated, tubular stems of jointed 

 aspect, with sharply projecting rings of growth, and with numerous 

 verticillate, transverse tubules connecting the stems at short inter- 

 vals. Diameter of tubes about one and a half millimeter. Dia- 

 phragms of the elongated, funnel-shaped form peculiar to the genus. 

 Found at Point Detour in the Niagara limestone, and in the drift 

 deposits of the Lower Peninsula. 



Plate XXXIL, Lower tier. — The two left figures represent silici- 

 fied specimens found in the drift of Ann Arbor. 



SYRINGOPORA TENELLA, N. Sr. 



Irregularly reticulated colonies of tubules, one millimeter in width, 

 or less. The tubules branch in the same manner as Aulopora, and 

 directly connect with each other by approximation, without the in- 

 tervention of narrower, transverse channels, as in other species of 

 Syringopora. The tubules exhibit a faint longitudinal striation on 

 the outside wall, and the cavity is lined by a cycle of twelve spinu- 

 lose crests. Diaphragms funnel-shaped, but not always developed ; 

 the channels are often found open throughout. 



Eound in the Niagara group of Point Detour, Drummond's Island, 

 and in the drift. Occurs also in Indiana and Kentucky. 



Plate XXX. — Fig. 4 represents a small specimen found in the 

 drift, seen from the basal side, with creeping, prostrate tubules. 

 On the upper side of the s])ecimcn the tubules are bent into an 

 erect position. 



