GENERA OF FAVQSITWM. 63 



drical, the prismatic angles of the tubes being obtusely rounded, 

 and varying from a line and a half to a line and three-quarters 

 in diameter. The small tubes are intercalated in the spaces 

 between the smaller ones, and are usually from a quarter to 

 half a line in diameter. Calices often in parts obliterated by 

 an epitheca. Septa represented by blunt tubercular ridges on 

 the inner faces of the walls of the tubes. Tabulae complete, 

 sometimes not developed in a perfect form, but always either 

 represented or accompanied by numerous close-set transverse 

 ridges or lamellae (" squamae "), which are to be regarded as 

 rudimentary tabulae, and which impart a peculiar rough aspect 

 to the inner surfaces of the corallites. 



This form is abundant in the Devonian deposits, and especi- 

 ally in the Corniferous Limestone, of Canada and the United 

 States, and it has a historical interest, as it is unquestionably 

 one of the forms figured by Goldfuss (loc. cit.} under the name 

 of F. basaltica. The specimen figured by Goldfuss is stated 

 in the text to come from Lake Erie ; and the accuracy of the 

 drawing places it beyond a shadow of doubt that it was a 

 silicified example of this form derived from the Corniferous 

 Limestone. Mr Billings, who clearly recognised this fact, 

 appropriated the name of F. basaltica, Goldf., for the form now 

 under consideration, upon the belief that the other forms 

 included by Goldfuss under the same title were really referable 

 to F. Gothlandica, Lam. I have before expressed the opinion 

 that we have not at present sufficient evidence to support this 

 course (Rep. on the Palaeontology of Ontario, p. 48). Those 

 forms included by Goldfuss under F. basaltica, which have 

 prismatic tubes and uniserial mural pores, may turn out ulti- 

 mately to be a variety of F. Gothlandica ; but there is not at 

 present any definite proof of this. I preferred, therefore, and 

 still prefer, to retain the name of F. basaltica, Goldf. if it is to 

 be retained at all for forms which essentially belong to the 

 type of F. Gothlandica, but have the mural pores uniserially 

 arranged. The present form, on the other hand, is clearly of 

 the type of F. Forbesi, E. and H., with conspicuously unequal 



