ii 7 



Zoarium circular, with a strongly developed marginal lamina, which may become free 

 and cup-like. Zooecia with a pronounced radial arrangement, those of the central region with 

 a depressed porous region passing into the projecting peristomial part. The peristomes are 

 connate, in radial series; at first uniserial, but more peripherally becoming biserial or triserial. 

 In fertile colonies the series of zooecia appear interrupted by the ovicells, but may bifurcate in 

 that region, so that the number of series is greater on the peripheral side of the ovicells than 

 in the central part of the colony. Outside the ovicells, the zooecia are usually in connate groups, 

 which are two or three zooecia wide. Ovicells transversely elongated ; when several are present, 

 forming a ring which extends round almost the entire circumference of the colony. The more 

 centrally placed zooecia are closed by a terminal or slightly depressed calcareous plate. 



The genus Liripora was founded by MacGili.ivrav (1887) for species which differ from 

 Diastopora \Berenicea\ in having the zooecia arranged in uniserial or multiserial radiating rows. 

 It appears to me possible that L. bicolor of the same author is identical with L. lineata. 



The bathymetrical range of this species is considerable (6 fathoms = 1 1 Metres, to 

 397 Metres), if the specimens here described are rightly referred to the same species. The 

 largest colony is shown in fig. 7 (424. A.), and measures 4.4 mm. in diameter, a size which 

 would have been slightly exceeded if the marginal lamina had been complete. The connate, 

 radial arrangement of the zooecia appears to be very characteristic of this species ; and this is 

 a sufficiënt reason for distinguishing it from B. patina Lamk, which it resembles in several 

 respects. The zooecia in these series are at first arranged in a single line, but become biserial 

 even on the central side of the ovicell, while more peripherally they are in two or three series. 

 The depressed parts, between the series, in the central region of the colony, are porous, and at 

 first sight might be mistaken for parts of the ovicells. More careful examination shows, however, 

 that these parts are divided by septal lines; and the specimen 104. C. (fig. 6) shows very distinctly 

 that these are really the edges of the walls between the zooecia, which are accordingly depressed 

 in the proximal part, becoming raised in their peristomial region into the constituents of the 

 radiating ridges. Consecutive zooecia of a series may have their depressed part on the same side 

 or on opposite sides of the peristomes; in the latter case an alternate disposition being indicated. 



It appears to be characteristic of the present genus that the centrally placed zooecia 

 cease to be functional at a relatively early stage. This is indicated by the fact that they are 

 terminated by the well known calcareous "closure". The shape of this closing plate offers good 

 characters for the discrimination of the species. In the present case the "closure" is of the type 

 characteristic of B. patina ; consisting of a nearly terminal plate provided with a few pores, 

 but not raised into a tubular prolongation. It may safely be assumed that the formation of the 

 terminal plate is a consequence of the degeneration of the polypide; and that the only zooecia 

 which possess functional polypides are those which have no "closure" and are situated in the 

 marginal region of the zoarium x ). The great development of the marginal lamina which is so 

 common in this genus is probably correlated with the fact that there is here an active growth 

 of new zooecia to replace the more centrally placed occluded zooecia. 



1) I have evidence, derived from a British specimen of B. samiensis, that the central zooecia contain no functional polypides. 



"7 



