426 THE CANADIAN NATURALIST. [Dec. 



sembles Heliolites, but differs therefrom in having double the num- 

 ber of septa and the walls perforated. 



C. Canadensis. — This species forms small hemispheric or 

 irregular masses with the corallites about one line, usually a little 

 more, in diameter and generally in contact although still re- 

 maining circular. Three tabulae in one line, in the specimens 

 examined. Mural pores in horizontal rows running all round the 

 tube, one row between each two tabulae. It occurs in the Black 

 River limestone near Ottawa. E. Billings. 



C. Huronensis. — Corallites somewhat less than one line in 

 diameter with a few others much smaller between them. They 

 are, in the same colony, in some places so closely crowded as to 

 become nearly hexagonal and elsewhere either in contact or sepa- 

 rated half their diameter from each other. The only specimen 

 collected seems to be a part of a tuberose mass. It is closely 

 allied to C. Canadensis, but has the corallites, in general, more 

 slender, and presents a different aspect. Hudson River formation, 

 Cape Smith, Lake Huron. Prof. R. Bell. 



C. Anticostiensis. — Corallum forming depressed hemispheric 

 masses. Corallites a little more than one line in diameter with 

 smaller ones between them, sometimes in contact, but, in general, 

 distant from one-fourth to one-half their diameter. Costae form- 

 ing a fringe around the apertures and also seen in vertical polished 

 sections. Intercellular tissue composed principally of thin, undu- 

 lating or flat horizontal diaphragms extending from tube to tube 

 and subdivided into square cells by the costae at the surface of the 

 walls. Tabulae obscurely seen, in the specimens observed, ap- 

 parently 'very thin. There are about three diaphragms and tab- 

 ulae in one line. The radiating septa form thin, sharp, strong, ele- 

 vated striae on the inside of the tubes where exposed in weathered 

 specimens. Closely allied to the two last, but has the corallites, in 

 general, somewhat larger and more distant. West side of Gamache 

 Bay, Anticosti ; Division 1 ; Anticosti group ; Middle Silurian. 

 T. C. Weston. 



Genus Heliolites, Dana. 



II. speciosus. — Corallum clavato-turbinate or sub-pyriform ; 

 cells a little more than one line in diameter, on an average, usually 

 about half their width distant from each other, but occasionally in 

 contact and sometimes more widely separated ; their margins thin, 

 elevated above the general surface, crenulated or ornamented with 

 twelve small rough tubercles. The septa seem to be only incipiently 



