466 MR. A. W. WATERS ON 



to be several pores in the large distal rosette-plate. There are 

 10 tentacles. 



Log. Wasin, Brit. E. Africa, 10 fath. (501) ; Ohuaka, Zanzibar, 

 2 fath. (508); Chaki-Ohaki Bay, Pemba Island, near Zanzibar 

 (517), collected by Orossland. 



Synkotum contobta, sp. n. (PI. LXIY. figs. 16-18.) 



Synnotwm aviculare Robertson. '' Non-Incrusting Bryozoa." 

 Univ. of Calif. Publ., Zool. vol. ii. p. 286, pi. xiv. figs. '84, 85 

 (1905). 



The zoarium is coiled up, especially at the end. The branches 

 of the zoarium dichotomise, and consist of pairs of zooecia back to 

 back directed alternately in the opposite directions at right 

 angles. 



The zoa3cia ai"e wide, subtruncate at the top, diminishing regu- 

 larly to the base, with a sessile avicularium at one or both sides 

 near the distal end, and there are a few large rounded, pedun- 

 culated aviculaiia, replacing one of the sessile avicularia, but none 

 of these are found in the older zooecia ; the area is large, occupying 

 more than two-thirds of the front, and the calcareous layer is much 

 more solid than in any other of the Gemellarid^e examined. The 

 first zooecia at the bifurcations are single, whereas the next ones 

 are double, being back to back. There are long radicles from the 

 side of the zooecia. In the lateral wall there are two rosette-plates 

 near the distal end. 



There are 11 tentacles. 



We know Gemellaria loricata L. without any avicularia, S. 

 pembaensis riov. with terminal pedunculated avicularia, the 

 present species with sessile avicularia and a few short thick 

 pedunculated avicularia, and S. aviculare also with both sessile 

 and pedunculated avicularia. The presence or absence of avi- 

 cularia is constantly turning out an unsatisfactory generic 

 character, and I have never felt quite satisfied that a new genus 

 was required for Synnoixim. 



Miss Robertson's figure shows the zooecia more attenuated 

 below, but it certainly seems that this is the species she 

 described. 



Loc. Chuaka, Zanzibar, 2 fath. (508); Chaki-Chaki, Pemba 

 Bay, near Zanzibar, low water (517) ; Wasin, Brit. East Africa, 

 10 fath. (501). 



Eucratea chelata Linn. 



See Miss Jelly's Catalogue, and add : — 



Scruparia chelata Kiixhcnpauer, Bericht iiber die Unter- 

 suchungs-Fahrt cler Pommerania, " Bryozoa," p. 181 (1875). 



Eucratea chelata Levinsen, Zool. Danica, p. 42, pi. i. figs. 8-9 ; 

 Calvet, Bry. de Cette, p. 12; Robertson, " Non-Incrusting 

 Bryozoa," IJniv. of Calif. Publ., Zool. vol. ii. p. 248, pi. v. figs. 7-9 

 (1905) ; Barrois, Emb. des Bry. p. 194, pi. xv. figs. 10-12 (1877) ; 



