OVICELLS OF SOME LICHEXOPORiE. 



283 



Through Miss Jelly's kindness I have been able to examine a 

 considerable number of specimens of Lichenoporce from Victoria, 

 and an abundant one is, I think, theZ. ecJiinata of MacGillivray. 

 The zooecia are irregularly arranged, the peristome is much pro- 

 duced on the proximal edge, namely, the margin nearest to the 

 centre of the zoarium, sometimes with one process, sometimes 

 divided into several ; numerous fine spines usually grow from the 

 zooecial tubes as well as from the cancelli aud the surface of the 

 ovicell. The cancelli are angular with rounded corners, though 

 when the tube is examined at some depth below the surface it is 

 often seen to be round, and some of the cancelli may be called 

 round, though that is not the usual character ; the entire inner 

 surface of the cancelli is denticulate. The ovicell is formed by 

 an inflated crust covering all the central area of the zoarium, and, 

 as shown in figure 6, it starts from numerous places, ultimately 

 meeting iu the centre : at first this crust is very thin, but in the 

 mature condition is deeply pitted ; the surface is then somewhat 

 ribbed and there are numerous small pores at the base of the pits. 

 In my previous paper to this Society (p. 277) I alluded to some- 

 what similar pits in Hornera. 



As soon as the growth of the ovicell commences the basal reticu- 

 lated cells of the central area are covered over by a thin pellicle 

 with several perforations to each cancellus. Both the upper and 

 under surface of the ovicell is shown in figure 6. Figure 3 is drawn 

 from a specimen bent up at the two sides, and it is impossible to 

 figure it satisfactorily, as it cannot all be seen in one focus. 



The opening of the ovicell is a wide tube low down at the 

 border of the inflation, directed horizontally, much in the same 

 w^ay as in L. ciliata (Ann. Mag. Nat. Hist. ser. 5, vol. xx. p. 263, 

 pi. vii. fig. 5); but I have only seen the one ovicell of i. ciliata 

 spreading among the zooecial tubes, and these two forms seem so 

 closely allied that I am in doubt as to the basis of their distinction. 



In some s[)ecimens the zooecia are slightly ridged, as in L. grig- 

 nonensis. The spines from the zooecial tubes are not constant, 

 sometimes occurring in great abundance, in others there are very 

 few or they may be entirely absent. Both in this and L. pristisy 

 MacGr., there is a semitransparent closure with a dull opaque 

 disk in the centre, perforated in the middle. It seems probable 

 that L. pristis aud L. ecJnnafa are only the simple and confluent 

 colonies of the same thijig. 



Log. Victoria; Tristan da Cunha (' Challeuger '). 



