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POLYZOA OF THE L.M.B.C. DISTRICT. 219 
calcareous spicules* in the peripheral parts of the gela- 
tinous ectocyst. Professor Herdman has described + some 
specimens obtained from the west coast of Scotland, and 
recently also from Puffin Island, t in which the colony was 
conspicuously spotted. These whitey spots were found on 
sectionizing to be very much enlarged “cells,’’ containing 
polypides, and greatly distended with mature spermatozoa. 
These colonies were virtually males, as none of the polypides 
were found to contain mature ova. A spotted colony col- 
lected lately at Puffin Island was found, however, to contain 
large numbers of ripe ova and embryos, but no spermatozoa. 
Professor Herdman has suggested that this unisexual 
condition may be the result of proterandry—the male 
reproductive organs being developed first, and the female 
later on, but he leaves it an open question whether the 
individual polypides are proterandrous hermaphrodites, or 
whether the polypides are unisexual and the proterandry 
refers only to the colony as a whole. 
Cellaria fistulosa, Linn. 
Some of the specimens of this species have afforded me 
material for investigating the mode of branching.§ The 
stems are dichotomously branched, but in some cases a 
lateral branch may originate in the middle of an internode 
(see fig. 1). When the branches are young they are rigidly 
connected by elongated cells, which have mouth opening 
and avicularia like those of ordinary cells (see fig. 2). As 
the branch elongates these cells break and display horny 
* Lomas, ‘‘Proc. L’pool Geol. Soc.,” vol. v., p. 241. Mr. Waters quite 
independently discovered these spicules, and communicated a paper on the 
subject to the Manchester Lit. and Phil. Soe. 
+See ‘‘Nature,” for Dec. 29th, 1887, p. 213. 
+ And I have seen at the British Museum a similar specimen, brought by 
Mr. Ridley from the Isle of Thanet. 
§ See Lomas, ‘‘Research,” for August, 1888, p, 22, 
