BY T. WHITELEGGE. 347 



viewed from above greatly resemble B. angidojiora, and if a little less 

 compressed might be mistaken for that species at first sight. The 

 avicularian cells are present in both specimens on the nodular 

 projection, and the similunar slits on various parts of the zoarium. 

 The slits can be seen even in very old specimens scattered about 

 on the surface. It is not difficult to trace the stages by which the 

 conical form might be changed into the flabellate, and afterwards 

 into the lobate form, and which has probably taken place. If we 

 imagine the internal cancellated layer to become less developed, 

 accompanied by a gradual compression, and the addition of a few 

 more rows of zocecia towards the outer margin, we can easily see 

 that we should have a form like B. elegans, which is in reality only 

 a flattened cone with the base widely extended, and in B. umhonata 

 the flabellate form is changed into a lobate one by the non-devel- 

 opment of a portion of the colony. So that the broad non- 

 divided end of the last-named species and the nodular portion of 

 the former correspond with the apex of the cone. 



Postscript. — Since the foregoing was written I have been fortu- 

 nate in obtaining some living examples of Bipora Fhilipjnnensis, 

 Busk, which I have had under observation for three days. Nearly 

 every specimen possesses a pair of tubular filaments inserted on 

 each side of the zoarium, about mid-way between the margin and 

 the summit on the upper surface ; each tube is about ^ an inch 

 lono- and in some cases attached to the tubes of an annelid, and 

 in others to fragments of shell. Some of the specimens have 

 besun to form new attachment tubes which are about thi'ee times 

 the height of the ooecia Each tube is seen to be lined with a 

 layer of sarcode similar to that seen in the growing oftshoots in 

 Victorella 2}avida, S. Kent, consisting of granular and fisiform 

 bodies which form a kind of net-work. The tube appears to grow 

 out of an avicularium either at the side or in front of the zooecial 

 orifice. After repeatedly counting the number of tentacles, I find 

 that they vary from 13 to 15. The pore above the mouth is 

 covered by a membrane, and the marginal x'ow of zorecia have 

 the peristome produced below into an acute triangular hyaline 

 point. 



