Polyzoa of Queen Charlotte Islands. 205 
towards a General History of the Marine Polyzoa”’), an Aus- 
tralian species; but there are differences in the habit of 
growth and in some of the details of structure which probably 
entitle it to a distinct name. ‘The present species is exceed- 
ingly delicate and of most graceful form. ‘The branches seem 
to be slightly attached and are commonly free towards the 
extremities; the tubes are remarkably slender, and the free 
portions are horizontally inclined rather than erect. 7’. per- 
fragilis bears much resemblance to D’Orbigny’s figure of his 
Idmonea cenomana (Pal. Frang., Terr. Crétacés, vol. v. Atlas, 
pl. 633. fig. 2). 
Tubulipora Dawsoni, n. sp. (Pl. LX. fig. 5.) 
Zoarium forming a spreading, irregularly shaped, intricate, 
coral-like mass, composed of many branches, much divided 
and subdivided dichotomously, which radiate from the point 
of origin and anastomose freely ; branches massive, of consi- 
derable width, somewhat compressed, flattened in front, ex- 
panding upwards, bifid or trifid at the extremities, which are 
cellular, recumbent or suberect, never adnate, but attached by 
numerous calcareous -offsets from the dorsal surface to the shell 
or stone on which the colony grows. Zowcia arranged (in 
part) in transverse rows (two to five in each), which slant 
slightly downwards, connate, with a large suborbicular orifice, 
increasing in height from the inner side outwards, so as to 
give a serrated appearance to the edge of the branch ; the rows 
sometimes extending to the centre of the branch, but not sepa- 
rated by any distinct mesial line, sometimes (and more com- 
monly) ranging along the sides, the centre being occupied 
by many detached cells irregularly distributed, with a sube~- 
bicular orifice, which is usually scarcely raised above tl 
surface ; walls thickly and minutely punctate; the dorsal sur 
face rounded, lineated longitudinally, punctate, often. with 
transverse furrows. 
Common amongsi the dredgings; on shells and stones. 
In this fine species the disposition of the cells connately in 
transverse rows is very much confined to the sides of the 
branch, and a striking characteristic is the crowd of scattered 
cells which very commonly fills the centre. The latter are 
generally very slightly raised above the surface of the zoarium. 
‘The rows vary in length and occasionally extend to the centre 
of the branch; but usually the condition is as I have de- 
scribed it. The zocecia composing them increase in height 
trom within outwards, and the tallest form a conspicuous line 
along the margin of the branch. The branches are for the 
