20 Dr. H. A. Nicholson on some new or 



binatus, Billings, the present form is distinguished by its not 

 assuming the remarkable shape of the former and by the want 

 of its peculiar epitheca, as well as by the commonly biserial 

 condition of the pores and the more closely set tabulse. 



Horizon and Locality. Abundant and well preserved in the 

 inferior Devonian deposits of La Baconniere, Mayenne. 



Favosites ? inosculans^ Nich. 

 (PI. I. figs. 4, 4a). 



Spec. char. Corallum forming a large mass of unknown 

 dimensions, the single specimen examined being 12 centims. 

 in length by 7 in ■width, and 4 in height. The coral- 

 lites are very minute, averaging half a millimetre in dia- 

 meter, and radiating gently from the base. Very commonly, 

 in fact in a large proportion of the corallites, the walls are 

 partially deficient ; so that two, three, or four adjoining tubes 

 may run into one another laterally in a vermiculate manner 

 (PI. T, fig. 4), the boundaries between the different ele- 

 ments of such a common tube being indicated by short mar- 

 ginal and opposed ridges. The line of demarcation between 

 the sclerenchyma of any one tube and that of its neighbours 

 is in general recognizable by the presence of a clear linear 

 space representing the primitive wall. The tabulae are nume- 

 rous, complete, and approximately horizontal. Septal spines 

 not observed. The mural pores are numerous, very large, 

 closely approximated, oval or rounded in shape, and arranged 

 in a single series on each face of a tube, six or eight pores, or 

 more, being present in a vertical space of 2 millimetres. 



Obs. In general shape and aspect this singular species is 

 very like a massive Alveolites or Chwtetes. Its corallites, 

 however, show nothing of the compressed and often crescentic 

 or lunate character of those of Alveolites, and it clearly cannot 

 be referred to this genus. On the other hand, it presents a 

 curious resemblance to Chcetetes in the imperfect condition of 

 the walls of the corallites, and the resulting presence of blunt 

 processes or ridges extending into the visceral chambers 

 (PI. I. fig. 4). In Chcetetes, however, this appearance is 

 due to the partial division of the old tubes, preparatory to 

 their complete fission, whereas in the present case the adult 

 tubes simply communicate with one another by a deficiency 

 of their parietes. That the present species is not a true 

 Chcetetes is also conclusively shown by the fact that the 

 duplex character of the walls of the tubes can be clearly re- 

 cognized, as well as by the presence of numerous large mural 

 pores. This last character proves it to belong to the Favo- 

 sitida?, though its reference to Favosites proper is rendered 



