122 A MONOGRAPH OF THE TERTIARY POLTZOA OP VICTORIA. 



3. I. atlantica, Edward Forbes. PL XVI., fig. 17; PL XVII., fig. 8. 



I. atlantica, Busk, B.M.C., III., 11 ; C.P., II., 10 ; Hincks, B.M.P., 451 ; McG., 

 T.E.S.V., 1886 ; Srnitt, Eloriclan Bryozoa, Pt. I., 6 ; Waters, Q.J.G.S., 1884, 683. 



Branches dichotoniously divided, triangular in section. Zocecia distinct, 

 connate, in alternate rows of two or three, the innermost being the longest, anterior 

 portions turned much forwards, smooth. Dorsal surface flat or slightly concave, 

 finely longitudinally sulcate and occasionally transversely corrugated, the ridges 

 between the sulci finely punctate. 



S.P. ; B. Living. Northern Europe, Madeira, Florida, Australia. 



4. I. contorta, Busk. PL XVII., figs. 4, 5. 



I. contorta, Busk, B.M.C., III., 12. 



Zoarium consisting of dichotomousiy divided branches. Zocecia in alternate 

 series of 4-6, distinct throughout but closely connate, the upper third sharply turned 

 forwards and nearly erect, smooth (from attrition) or finely punctate. Dorsal 

 surface longitudinally finely ridged, the ridges continuous and separated by narrow 

 grooves. 



B. ; C.B. Living. New Zealand. 



The zocecia are distinctly separated throughout by shallow grooves which, 

 however, in some specimens are replaced by narrow raised lines. The ridges also 

 on the back, are usually separated by narrow grooves which, with age, are 

 similarly replaced by narrow raised lines. 



In the fossil specimens the branches are nearly or quite straight, while in the 

 recent they are short and contorted. I have, however, one recent specimen from 

 New Zealand in which the branches are almost straight, so that I see no reason for 

 separating the present even as a variety. 



5. I. gevninata, n.sp. PL XVII. , fig. 7. 



Branches rounded in front, slightly hollowed behind ; whole surface closely 

 punctate. Zocecia elongated, indistinct, arranged in alternate series of two, united 

 except at the extremities. Dorsal surface transversely rugose. 



S.P. 



6. I. trigona, n.sp. PL XVII. . fig. 6. 



Zoarium dichotomousiy branched ; branches trigonal in section, posteriorly very 

 slightly convex, flat or usually slightly hollowed. Zocecia in alternate series of 

 three, distinct throughout, curved slightly forwards at the anterior extremity, 



