OVICELLS OF CrCLOSTOMATOUS liRYOZOA. 



279 



iiuiqiie structure ; and, so far as I am aware, nothing of the kind 

 has before been found. The base is narrow, but the sac widens 

 out, and then again becomes narrower ; the surface has a few 

 large oval pores, and the oviceUuLar opening is a raised tube at 

 one upper corner. The zocecial tubes spread out at the ends. 



It is placed, with hesitation, under I. Meneghini, as there are 

 only four zooecia to a series ; but Heller only figures four, and 

 the number is not always constant in a colony. In a specimen 

 from Naples, without an ovicell, of what I considered I. Mene- 

 ghini, the zooecial tubes do not spread out at the end in the same 

 way ; but sometimes a trace of this structure can be seen. The 

 dorsal surface near tiie ends of the branches is finely punc- 

 tured, but near the base there are larger openings. I have 

 only the one specimen with ovicells. 



Idmo]^ea irrequlares, MenegJiini. (PI. XIV. figs. 5 and 6.) 



This was found by the ' Challenger' off the Azores ; and Mr. 

 Busk (p. 14) says, " ooecial chamber? " 



I have, however, previously (see Ann. Mag. Nat. Hist. ser. 5, 

 vol. XX. p. 257, and Quart. Journ. Geol. Soc. vol. xl. p. 687) 

 referred to the dorsal ovicell of I. irregularis \ but as it has 

 never been figured, a normal ovicell is given (fig. 5) and a short 

 abnormal one (fig. 6). 



The ovicellular aperture is wide, with a raised irregular funnel- 

 shaped opening ; but in the young ovicells the upper part is flat, 

 sloping inwards. One colony has eight ovicells, and five of 

 these are intact, without showing any opening ; and from this 

 we see how misleading this specimen alone would have been, 

 as the young ovicells are without external orifices. 



A somewhat similar ovicell occurs on Filisparsa orakeiensiSf 

 Stol. {loc. cit. p. 687). 



IdMONEA MlLNEANA, d'Orh. (PI. XIV. fig. 8.) 



I have already referred to the ovicell of /. Milneana (Ann. 

 Mag. Nat. Hist. ser. 5, vol. xx. p. 256), and give a figure from a 

 Capri specimen, and may repeat that the British Museum speci- 

 mens of jT. notomala, B., and /. Milneana, d'Orb., are so similar 

 that they might be fragments of the same colony. The ovicell 

 is figured from a rather broken-down s[)ecinien, ajid therefore 

 there is some restoration of tlie zooecial tubes. 



