NORTH AMERICAN EARLY TERTIARY BRYOZOA. 



571 



Genus DIMORPHOCELLA Maplestone, 1903. 



1903. Dimorpltocella MAPI.ESTONK, Further descriptions of the Tertiary Polyzoa of Victoria, 

 Article IX, Transactions Roy.il Society Victoria, p. 140. 



"Two distinct forms of cells. Zooecial cells elongated or rhomboidal. distinct. 

 Thyrostome [aperture] arched above, with a sinus in the lower lip. Ooecial cells 

 [gonoecia] much larger than the zooecia, elongate, pyriform or oval, with a hrnad 

 aperture and a perforated area in front." (Maplestone.) 



Genotype. D'nno-rphocclla (Adeonella) triton MacGillivray, 1895. Miocene. 



The other known species of this genus are : 



Dimorphocella pyriformis Maplestone, 1903. Miocene. 



Dimorphocella porfmarina Maplestone, 1903. Recent. 



FIG. 170. Genus Dimorphocella Maplestone, 11303. 



A, B. Dimorphocella triton MacGillivray, 1895. A. Group of zooecia, including gonoeeia. 

 B. Normal zooecia. (A, B after MacGillivray, 1S95.) 



0. Dimorphocella jiortmnriitu Maplestonc, 1903. Group of zooecia, X 24. (After Maple- 

 stone, 1903.) 



According to the definition and examination of the figures the ordinary zooecin 

 have no ascopores, whereas the. gonoecia are provided with them. On the recent 

 species Dimorphocella port-marina there are some ascopores on tlje two kinds of 

 zooecia. Further studv is therefore necessary to establish the validity of this genii-;. 



Genus LAMINOPORA Michelin, 1842. 



1842. Laminopora MICHELIN, Magasiu de Zoologie, pi. 3. 



The apertura is very elongate; the anter is semielliptical ; the poster bears a 

 long, rounded rimule; two small cardelles separate the two latter parts; the oper- 

 culum bears two lateral denticles articulating on the cardelles. The frontal is a 

 tremocyst with pores not stellate. The gonoecia have no special form. 13-15 

 tentacles. 



Genotype. Laminopora contorts Michelin. 1842. Recent. 



Gemellipora arbmcula Calvet. 1907, belongs to this genus. 



