154 



ooecia have hitherto not been made out with certainty, neither in fossil nor in 

 recent species of this genus; but the reference of the above mentioned species to 

 the genus Omjchocella does not seem to me to be unquestionable. The presence 

 of avicularia with wing-shaped lateral expansions is not conclusive. I have found 

 quite similar avicularia in a tropical Microporella s])ecies. With regard to the 

 zon?cia themselves they seem to be more like tliose found in (killopora Flemingi 

 and cognate species, as there seems to be a distinction between a strongly de- 

 pressed cryptocysl surrounded by a projecting margin and an arched, jiroximal 

 gymnocyst. The rather large ooecium issues from I he la Her and is in size, form 

 and position unliUc the ooecia, which I have found in a series of recent and 

 fossil species of the genus, and which are very little conspicuous, so little in fact, 

 that they have hitherto been overlooked. 



While all the other zoa?cia have a sharp and deep sutural funow in the 

 whole of their periphery, which forms the l)oun(Jary between the projecting mar- 

 gins of their own and those of the surrountling zorecia, such a sutural furrow is 

 wanting in the distal end of the ooecium-bearing zoa'cia, and the proximal end 

 of the distal zoa^cium does not as in the other zocrcia end in a low, rounded, 

 projecting margin, but in a somewhat higher, more or less distinctly prominent 

 swelling (the frontal wall of the oa'cium) which is but indistinctly marked ofT 

 from the zoci'cium, and wliich seems to be covered by its frontal membrane. 

 This slightly prominent, rounded pent-roof is on either side separated from the 

 marginal cryptocyst of the proximal zoa-cium by a sutural furrow, hi the interior 

 the frontally ascending distal wall touches the distal end of this swelling, and 

 between the zocecial operculum and the margin of the occcium we find a slightly 

 chitinized ocecial operculujn. Reference may be made to the schematic figure 

 (PI. XXIV, fig. 10.), the dotted lines in which show how I picture the inner 

 parts of this oa^ciuni. 



Cupularia Lamouroux. 



The zowcia broadU' rhombic, without frontal gymnocyst, but with a depressed 

 cryptocyst perforated by a larger or smaller ajierlure. No spines. Each distal wall 

 with one, and the distal half of each lateral wall with several (u]) to (i), scatte- 

 red, uniporous rosette-plates. The lateral walls are common to the contiguous 

 neighbouring zooecia. On the distal side of each zonecium we find an asymme- 

 trical, independent vibraculnm with a long tlagelhim and an angularly bent, kid- 

 ney- or bean-shaped opening. No owcia. The species hitherto described occur in 

 free, discoidal colonies witli a thick basal surface covered by a membrane, the 

 radiating furrows of which correspond with radiately arranged zocecial rows. 



