Plumularia. 
Z. HYDKOIDA. 
149 
The roots are matted together with numerous entangled fibres. 
Stalks 6 inches in height or more, the largest as thick as a crow-quill, 
yellowish-brown, straight or slightly curved, swollen at intervals on 
the back, and simple or once divided : they are each of them com- 
posed of a number of tubes bound together, as is easily seen on a 
transverse section, and the oblong dorsal knobs seem to be produced 
by a less close adhesion of the tubes at these places, “ marking pro- 
bably the stages of growth.’’ The branches or pinnae spring from 
both sides beginning about the middle of the stalk, the lower part be- 
ing naked, but they incline so much one way as to appear unilateral. 
The wide cylindrical cells are divided from each other by a joint, and 
are seated in the axil of a curved spinous process which projects far 
enough to form a short tooth at the under side of the aperture. — 
When dry the stalk is twisted and more distinctly perceived to be 
composed of a bundle of tubes, and consequently furrowed. In each 
of the furrows there is a row of small holes with a raised brim as if 
punctures had been made by an instrument pushed from within. The 
holes are close- set, and regular in their size, form, and in the distances 
between them. 
8. P. frutescens, stem branched , the branches pinnate; 
pinnce alternate , bifid; cells infundibuliform , leaning , rather dis- 
tant , the mouth plain . Ellis. 
Plate XX. Fig. 2, 3. 
Sertularia Gorgonia, Pall. Elench. 158. S. frutescens, Ellis and So - 
land. Zooph. 55. pi. 6, fig. a, A. and pi. 9. fig 1, 2, encrusted with a 
Gorgonia. Turt. Gmel. iv. 680. Turt. Brit. Faun. 214. Stew. Elem. 
ii. 445. Bose , Vers, iii. 113. Hogg's Stock. 33.- Aglaophenia fru- 
tescens, Lamour. Cor. Flex. 173. Corall. 76. Plumularia frutescens, 
Flem. Brit. Anim. 547. Lam. Anim. s. Vert. 2de edit. ii. 166 La 
P. frutescente, Blainv. Actinolog. 477. 
Hab. Found at Scarborough in Yorkshire, Ellis , — whence I have 
specimens from Mr Bean , who states that it inhabits deep water, 
where it grows attached to stones and shells by a fibrous base, and is 
very rare. Hartlepool, Durham, J . Hogg, Esq. 
Polypidom between four and five inches in height, firm and woody, 
black or dusky-brown, varnished, irregularly branched. Stem and 
branches tapered, composed of many parallel twisted capillary tubes, 
the branches erecto-patent, spreading laterally, pinnate ; pinnae rather 
close, alternate, two or three from each space between the joints, and 
each divided into two branches. Cells rather distant, adnate, cylin- 
drical widening outwards, smooth, with an entire slightly everted 
margin : there is a small cell in the axils of the pinnae, and a den- 
