A. W. WATERS—REPORT ON THE BRYOZOA. 249 
B. caudata, showing them sometimes branched, and considered them to be the 
commencement of a new outrunner from the stem. 
Loppens * calls B. caudata a variety of B. imbricata and says: “ loges fixées 
latéralement au stolon, terminées en pointes, on trouve fréquemment les deux 
formes dans une méme colonie.”? Surely, then, it is not a variety, and I agree 
with Loppens in thinking that B. caudata is not a good species ; but Hincks 
says that it is much smaller than imbricata, so that in all probability it is 
only B. pustulosa, in which we know that these zocecial attachments occur. 
Ostroumoff f figures processes from the side of his Vestcularia stationis. I am 
not sure what this is, for Ostroumoff regards it as most closely allied to 
Valkeria uva, but he figures a gizzard. Probably V. stationis is Bowerbankia. 
B. imbricata is a much stouter species than B. pustulosa, with a much 
larger gizzard, furnishing a useful character in determination. Many of the 
determinations of both species require confirmation, for in the earlier descrip- 
tions there is inextricable confusion between B. imbricata, B. pustulosa, and 
Valkeria uva, for all three species may form thick growths over seaweed as 
described under the name densa. Thompson, in his figure of Valkeria cuscuta, 
shows a gizzard, proving that he had the zocecium of some other species 
before him ; also Smitt mixed up Valkeria uva and Bowerbankia imbricata, 
which accounts for his saying sometimes with and sometimes without a 
gizzard. The muscles of the gizzard show ecross-lines in section (ele 25: 
fig. 9), and the same is the case in the muscles of B. pustulosa. 
The Farella arctica, Busk, which is in the British Museum, is but a very 
poor specimen, and is apparently Bowerbankia, certainly not Farella. 
The gizzard of Bowerbankia imbricata is the largest of any that have come 
under my notice, measuring in sections about 0:J. mm. transversely in an 
ordinary non-inflated condition ; Zoobotryon pellucidum about 0-08 mm. : 
Bowerbankia pustulosa about 0°07 mm. ; Amathia Brongniartii, Desm. & Les., 
0:07 mm. ; Buskia socialis, Hincks, about 0°07 mm. ; Amathia lendigera, Linn., 
about 0:05-0:06 mm. ; Vesicularia spinosa, L., about 0-04-0°05 mm. ; Crypto- 
polyzoon about 0-02-0°03 mm. 
There seems no character yet described by which Bowerbankia can be 
distinguished from Zoobotryon, but it is provisionally left until the whole of 
the Ctenostomata have been fully studied. 
Loe. Arctic; Danish, Belgian, French, and British coasts; Mediterranean ; 
Alaska ; California, Queen Charlotte Island (Robertson) ; Caspian Sea (fide 
Grimm) ; Bay of Agig Suraya (south part of Sudan coast, 21), collected by 
Crossland. 
* “ Bry. Marins et Fluviatiles de la Belgique,” Ann. Soc. Roy. Zool. & Malac, de 
Belgique, vol. xli. (1996) p. 286. 
+ “Etudes Zool. & Morph. des Bry.,’’ Arch. Slaves de Biol. vol. i. (1886) p. 567, pl. 4 
figs. 49-52, pl. 5. fig. 64. (This is a translation of a Russian paper.) 
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