BRYOZOA FROM ZANZIBAR. 459 



(2) The nature of the articulation can be xised in grouping the 

 Scrupocellaridpe, the other chai-acters being the ovicells, vibracula 

 (especially the number at a bifurcation), and the band, perhaps a 

 spermotheca at the distal end. 



(3) The difference in form and position of the ovaiia in Bvgida 

 and Scrupocellaria gives a generic character, and the same is the 

 case in other genera (p. 476). The form of the ovaria is likely 

 to give us considerable assistance in classification, but as the 

 ovaria pass through various stages of development, time and 

 caution are requisite to make it fully available. 



(4) In Memhranijjora armata Hasw. there are two mature 

 polypides in most zooecia, and on one side of the zooecium there is 

 a long chambered avicularium, whereas on the other side there is 

 a similar long chamber containing a secreting gland (p. 488). 



(5) In some species of Schizoporella a bar curving towards the 

 siniis is seen across the operculum. This is the commencement 

 of the lower wall of another zooecial layer, and in many cases the 

 distal walls are seen to extend over the operculum (p. 504). 



(6) In Dijjlodidymia complicata Rss. a small ovum starts in 

 a small sac hanging down from the opercular region. Both grow 

 lai'ge, and the larva ultimately fills up a large portion of the 

 zooecium (p. 491). 



Some of the species in this collection were also found in 

 Crossland's Red Sea collections, and my report thereon is quoted 

 with a shortened reference *. 



This communication may be considered as part of a series 

 dealing with tropical forms, of which three papers on the Red 

 Sea etc. have been published ; and I have a small collection from 

 Cape Verde, also collected by Orossland. 



From the locality Wasin about 60 species were procured, and 

 from Ras Osowamembe about 30 in all. 



Since the examination of this Zanzibar collection was com- 

 menced, Levinsen has published his ' Morphological and Systematic 

 Studies on the Cheilostomous Bryozoa,' and we have for some time 

 been anxious to see his ideas on classification developed. He has 

 given the particulars of much valuable detail examination of the 

 calcareous parts of the Bryozoa, and doubtless many of the cha- 

 racters he deals with will receive increased attention, and our 

 knowledge is much advanced by the wealth of observation. 



Unquestionably much of his altered classification will be 

 adopted ; but if any of us thought that all our troubles would 

 be ended as soon as Levinsen published his results, we find that 

 this is far from being the case. We have to examine each new 

 grouping, and see whether, when other characteis are examined, 

 they uphold suggested alterations ; also, do other species of the 

 groups fall into place ? I already see where some modifications 

 will be required, and no doubt other workers who have carefully 



* Jouni. Linn. Soc, Zool. vol. xxxi, pp. 123-181, 231-256. 



