BRYOZOA B^HOM ZANZIBAR. 489 



former species, and does not reach to the border of the opesiina, 

 so that they can be distinguished by this character. * 



Log. Widely distributed, but there is much uncertaint}' about 

 some of the determinations. Chuaka, Zanzibar, 3 fath. (506), 

 2 fath. (508), on the dorsal surface of Steganojjorella magnilabris B., 

 collected by Crossland. 



Farcimia oculata Busk. (PI. LXYII. figs. 8, 9.) 



For synonyms see : — 



Farcimia ocidata Waters, " Rep. on the Mar. Biol, of the 

 Sudanese Red Sea, Bryozoa,'' Journ. Linn. Soc, Zool. vol. xxxi. 

 p. 167 (1909) ; and add Canu, "Bry. des Terrains Tert. des Env. 

 de Paris," Ann. de Paleont. vol. ii. p. 20, pi. ii. figs. 36, 37 (1907) ; 

 " Bry. Helv. deTEgypte," Mem. a I'lnst. Egyptien, vol. vi. p. 191, 

 pi. X. figs. 16-19 (1912). 



Nellia tenella Lavinsen, Morph. & Syst. Studies of the Cheil. 

 Bry. p. 120, pi. i. figs. 13a-13 e (1909). 



The growth is from a spreading stolon from which, at intei-vals, 

 sub-colonies grow (figs. 8, 9), commencing with short calcareous 

 nodes joined by chitinous tubes. There are usually three or four 

 nodes in the stalk, though ther-e may be only one. Quite simi- 

 larly sub-colonies on a stalk with internodes grow from delicate 

 stolons in C/ilidonia cordieri Aud., Diplodidymia complicata 

 Reuss (PI. LXVII. figs. 11, 12), Catenaria parasitica Busk*. 

 I figured it some years ago for Ghlidonia cordieri Aud. T, aud 

 since then Calvet and Levinsen have dealt with the species. All 

 these species have a somewhat similar opei'culum, about the same 

 size, and the number of tentacles in all is 11-12. They are 

 probably more nearly related than we have imagined. 



There are two very thick chitinous tubes connecting each new 

 branch. 



The ovarium, with several ovarian cells, often in a row, is near 

 to the inner wall, about equidistant from the distal and proximal 

 ends. One ovum grows extremely large, and is pressed into all 

 kinds of shapes through want of room. The ovum passes into a 

 sac near the basal wall and the distal end, and before an ovuia 

 has passed into it muscle-threads are seen radiating over this sac, 



Levinsen has figured the ovicell, which is a small cap-like 

 growth, and this I have seen in a few cases, but often in zooecia 

 with ovicelligerous zooecia no external difierence is i-ecognised. 

 There is, however, often a vertical division separating the ovi- 

 cellular wall from the rest of the zocecium. 



The triangular mandible of the avicularium is found with 

 difficulty and is extremely minute, being about 0*006 mm., while 

 a large number of the mandibles, such, for example, as in Retepora 

 cellidosa, are 35 times as long ; some, as for example iu Lepralia 



* The Hnnourable Mary Palk informs me that Catenaria lafontii Ami., grows on 

 a similar stalk. 



f Jouru. Linn. Soc, Zool. vol. xxvi. pi. i. fig. 8 (1896). 



