STOMATOPORA INCURVATA. 433 



Stomatopora incurvata, Hincks. 

 Plate LXIV. figs. 6-8. 



TuBULiPOEA iNCURVATA, Hlncfcs, Eep. Belfast Dredg. Com., in Rep. Bi-it. 



Assoc. 1858. 

 Alecto incurvata, id. Proc. Dublin Univ. Zool. & Bot. Assoc, ii. pt. 1 



(1860), 77 ; Quart. Journ. Micr. So. -viii. (1860), 279, pi. 



XXX. fig. 6. 



Zoariuni adherent^ linear, unbranched, curved, attenuated 

 towards the point of origin, and of equal width above. 

 Zo(£cia biserial (except towards the base of the zoarium, 

 where they form a single row), alternate, separated by 

 a median line, the walls usually much thickened, the 

 oral extremity bent abruptly towards the side, the ori- 

 fices opening out laterally ; surface obscurely punc- 

 tate. 



Length of fine specimens rather more than a | inch. 



This species is at once recognized by its simple linear 

 zoarium, which is always more or less curved, and is fre- 

 quently very decidedly curled towards the base. The 

 cells are normally biserial; but specimens not uncom- 

 monly occur in which only a single series is developed, 

 and in all cases the basal portion of the zoarium is uni- 

 serial. They are disposed with much regularity, bending 

 alternately and abruptly to opposite sides of the zoarium ; 

 the orifice, which is small, opens out laterally and is not 

 at all visible when the specimen is viewed in front. The 

 bent anterior portion of the cell is not free, but is adnate 

 to the zoarium ; it is often massive and somewhat qua- 

 drate in form. 



As in others of the tribe, the zoarium originates in a 

 small suborbicular disk or button, from which the first 

 zooecium is developed. 



2f 



