7 2 



B. pustit/osa, which had been brought by Dr v. Martens from Yokohama", and had been 

 recorded by Kirchenpauer *). 



I think there is a high probability that the 'Siboga' specimens belong to the species 

 which has been recorded by Waters, from the Red Sea, as B. imbricata, although I am not 

 certain that his determination is correct. The specimens under consideration resemble those 

 figured by Waters, but I cannot believe that the alimentary canal is correctly represented in 

 fig. 8 of that author. It may also be identical with the B. caudata described by Annandale 2 ) 

 from Indian localities. But Waters does not admit that B. caudata is a good species, and 

 points out that the tail-like process at the basal end of the zooecium is not distinctive, as it 

 also occurs in some individuals of undoubted B. imbricata. The specimen (374. K.) figured 

 in the present Report has no basal processes, which are, however, present in other 'Siboga' 

 specimens (325. J., 382. B., 130 M.) ; either as a pointed prolongation of the kind figured by 

 Annandale, or more commonly as several irregular processes,. like those shown by Waters in 

 his PI. XXV, fig. 10 ; and regarded by him as rooting structures by means of which the 

 zooecium is attached to its substratum. B. imbricata, according to the same author (p. 249) 

 has the largest gizzard of any species with which he is acquainted, its transverse diameter being 

 about 100 a. This is in fair agreement with my own measurement of the gizzard of the specimen 

 shown in fig. 16; the transverse diameter of which I find to be 90 u.. If the number of tentacles 

 in the 'Siboga' specimens is 10, as I think is probably the case, this is a further agreement with 

 B. imbricata-, some of the other species of the genus being known to have only 8 tentacles. 



Miss Robertson 3 ) has recorded B. imbricata from the American side of the Pacific; 

 but she has given no description of the specimens found there. 



Group D. Stolonifera Ehlers. 



Stolonifera (pars), Ehlers, 1876, "■Hy pophor ella expansa' , Abh. K. Ges. Göttingen, XXI, p. 126. 

 Stolonifera Waters, 1910, "Rep. Mar. Biol. Sud. Red Sea", "Bry. II", J. Linn. Soc. Zool., 

 XXXI, p. 241. 



Waters, 1. cit., has proposed a new grouping of the genera formerly placed together as 

 Stolonifera; and the distinctive characters of the Stolonifera, as thus restricted by him, have 

 been stated above, on p. 43. The axis, in this group, is delicate, and thus contrasts with 

 the more massive axis of the Vesicularina. It expands slightly here and there, a diaphragm 

 being formed immediately on the distal side of the expansion, which gives rise either to new 

 stolon-branches or directly to zooecia, which are usually arranged in pairs. A gizzard is 

 usually absent. 



1) The reference to Kirchentauer's Memoir, which is not given by HlNCKS, is "Zoolog. Ergebn. Nordseefahrt", VI. "Bryozoa", 

 II Jahresb. Komm. Cnt. deutsch. Meere Kiel, 1874, p. 192. 



2) ANNANDALE, N., 191 1, "Fauna of Brit. India", "Freshwater Sponges, Ilydroids and Polyzoa", p. 189. See also the reference 

 to Miss T110RNEI.Y, there given. 



3) Robertson, A., 1900, "Papers Harriman Alaska Exp.", Proc. Washington Acad. Sci., II, p. 331. In "Non-incrnst. Cheil. 

 Bry. W. Coast N. Amer." (Univ. Cal. Publ. Zool., II, N° 5, 1905, p. 239) she figures "/?. imbrkata" with 8 tentacles, a fact which throws 

 poubt on the correctness of the other determination. 



72 



