LAURA R. THORNELY—REPORT ON THE HYDROIDA. rol 
Suborder ATHECATA. 
Family BOUGAINVILLIID &. 
PERIGONIMUS VAGANS, sp. n. (Plate 9. fig. 1.) 
Trophosome.—Colony much branched, about 1} inches in height. Branches 
alternate, but inclining all to one side, narrower than the stem and narrowest 
at the base, where there are a few corrugations. The whole perisare is 
coated with sand, giving the colony a yellowish colour. 
Polypites, some small on short stalks and with few tentacles, some larger 
on longer stalks with about 25 tentacles. Both sizes carry gonophores. 
(ronosome.—Gonophores borne on short stems, situated on the branches 
close below the hydranth and containing one medusa each. 
Locality— Khor Shinab, 10-12 fathoms. 
Family EUDENDRIID &. 
EUDENDRIUM RAMOSUM, Linné. 
Some fragments, probably belonging to this species. 
Locality—Khor Dongola, 3 fathoms. 
Family PENNARIID &. 
PENNARIA SYMMETRICA, Clark *. 
Numerous colonies, broken at their bases, 5 inches by 14 inches in size, 
without gonophores. 
Localities. —Shab al Shubuk ; quay-side, Suakim. 
Suborder THECAPHORA, 
Family CAMPANULARIIDA, 
OBELIA BiruRCATA, Hincks t. (Plate 9. fig. 2. 
The height of this species is not given by Hincks, but as it is growing on 
asmall polyzoon, Nellia oculata, it cannot be large. The present colonies are 
under an inch in height. Hincks’s species had a simple stem, while these are 
slightly branched and have the rudiments of a polysiphonic stem, as described 
by Bale for his Campanularia spinulosa. The very long hydrothece with 
about 12 bicuspid denticles, which are not sharp-pointed, borne on short 
ringed stems, are, however, the same as described for this species by Hincks 
* Bull. Mus. Comp. Zool. Harvard, vol. v. no. i0, 
+ Journ. Linn, Soe., Zool. vol. xxi. 1889, p. 133. 
