Vol. IX, No. 6.} The Polyzoa of the Lake of Tiberias. 227 
[NV.8.j 
generally to be the case that if the walls of a zooecium contain- 
ing statoblasts persist after the polypide has degenerated, they 
tend to become specialized in this way. 
Plumatella auricomis, sp. nov. 
Colony smail, recumbent, with short horizontal branches 
closely pressed together. 
Zooecia short, stout, L-shaped, cylindrical, with no trace of 
a dorsal keel or r furrow; ectocyst greatly thickened, colourless, 
hyaline, stiff and neither contractile nor seca of being thrown 
into furrows by the retraction of the pol 
Polypide slender, deeply pigmented, the ited katy canal 
being of a deep o range-brown, darker on the stomach than 
tentacles pale golden yellow, long, slender, comparatively few 
in number ; velum at their base very narrow. 
Statoblasts. No free statoblasts were observed. One colony 
contained a single fixed statoblast, which is narrowly oval, its 
t 
Habitat.—Lake of Tiberias, Palestin 
Type.—Z. KE. V. No. +, Ind. ae 
Unfortunately the material at my disposal is so scanty 
and so imperfect that I am unable to give a fuller description 
or an adequate figure. Only two colonies were found, and one 
of them was not observed until it had been plunged i in spirit. 
The other was carefully narcotized and fixed, but I find on re- 
examining it after some months se it is not in much better 
condition than the other. The species, however, is distin- 
guished from all others that have ae described by two im- 
portant characters, the thick, hyaline, stiff ectocyst without 
a dorsal keel furrow and the yellow colour of the lophophore. 
The latter is a feature, so fanaa I am aware, unique in the 
Polyz zoa. The ectocyst is much thicker than in Plumatella 
javanica and differs from that of P. punctata in not being soft 
and contractile. It shrivels greatly in spirit. My description 
is based mainly on field notes. 
Both colonies were dredged in between 6 and 8 metres of 
water in the channel of the R. Jordan as it flows through the 
south cal of the lake between the village of Semakh and its 
exit, and both were attached to shells of Unio terminalis. 
e, the larger of the two, was growing at one end of one shell 
of a living mollusc, just outside the siphonal aperture; the 
other, which contained the only statoblast seen, was fixed to 
