24 ME. A. W. WATERS ON 



JRJiamjpliostomella is a genus established by Lorenz*, and of which 

 Mr. Hincks t has given a revised diagnosis ; from this the present 

 fossil differs in having pores round the border of the zooecia, and in 

 apparently not having the oviccll perforate. It is, however, so 

 clearly allied to forms placed under WianipJiostomella that the 

 diagnosis of the genus must be altered to include it. It is not, 

 however, yet quite certain that the genus is based upon satisfactory 

 characters. 



Log. Eossil : Brendola ; Montecchio Maggiore (?) ; Val di Lonte. 



45. PoRiNA (?) coEONATA (Eouss). (PI. lY. figs. 1-5, 15.) 



Cellaria coronata, Heuss, Foss. Polyp. Wien. Tert. p. 62, pl. viii. 

 fig. 3. 



Eschara conferta, Eeuss, op. cit. p. 71, pl. viii. fig. 32. 



Acropora coronata, Eeuss, Bryoz. von Crosaro, p. 277, pl. xxxiv. 

 figs. 3-5. 



Porina coronata, Koschinsky, Bryoz. alt. Tert. siidl. Bayerns, 

 p. 42, pl. iv. figs. 7-9. 



This is a most variable species, and the studj^ of better-cleaned 

 specimens and the preparation of further sections have led me to 

 alter my views very materially. I have found it extremely difiicult 

 to satisfy mj^self as to the suboral pore, since the tube from the 

 suboral avicularium and the suboral pore end close together, near 

 to the oral aperture ; but I have at last obtained sections showing 

 that, contrary to what I thought from earlier preparations, the 

 suboral pore enters the zooecial cavity just below the oral aperture. 

 This is very important, as it shows that, if we are to consider the 

 position of the suboral pore as of first moment, this species must 

 be removed from Porina ; and as the position of the pore is nearly 

 the same in Tiibucellaria cereoides, we may have to remove it to 

 Tuhucellaria. 



There is considerable variation in the shape of the zoarium, it 

 being sometimes cylindrical, at others compressed ; and there is also 

 great variation in the pores or avicularia round the aperture, which 

 are sometimes scarcely distinguishable from those covering the 

 front of the zooecia ; in other cases they are very distinct ; and 

 there is usually a triangular avicularium directed distally just below 

 the oral aperture and above the suboral pore. In some zoaria there 

 are a few large ra'sed avicularia with broadly spatulate openings, 

 and these seem to be merely suboral avicularia modified. 



Sections of the interior show the tubular connections from zooecia 

 to zooecia, to which I referred in my 'Challenger' Supplementary 

 Eeport, p. 32. The branches dichotomize; and in a few cases 

 there are at the distal end of the branch openings for the chitinous 

 tubes, showing that there has been articulation. In the specimen 

 fig. 4 a fracture has taken place where the stem becomes thinner, 

 presumably after death. In the slender forms, such as fig. 5, there 



* " Bryozoen -von Jan Mayen, Interuatiouale Polarforschung," Akacl. Wis- 

 senscli. vol. iii. p. 93. 



+ Ann. Mag. Nat. Hist. ser. 6, vol. iii. p. 424. 



