152 
Z. HYDROIDA. 
Laomedea. 
Vert. ii. 120. 2de edit. ii. 149. Hogg's Stock. 33 — — Laomedea geni- 
culata, Lamour. Cor. Flex. 208. Corall. 91. Templeton in Mag. Nat. 
Hist. ix. 466. La L. geniculee, Blainv. Actinol. 474. Campanularia 
geniculata, Flem. Brit. Anira. 548. Johnston in Trans. Newc. Soc. ii. 
255. 
Hah . Parasitical and gregarious on sea weeds that grow near low- 
tide mark, especially on the frond of Laminaria digitata, very com- 
mon. 
Polypidom attached by a creeping tubular thread, erect, about an 
inch in height, simple or sparingly branched, regularly zig-zag, slen- 
der and flexile, of a clear white colour, often tinted more or less with 
rose-red, and filled with a dusky granular pulp : at every flexure, the 
stem is divided by a single joint and incrassated, a twisted pedicle 
originating from the incrassated part alternately from opposite sides ; 
the pedicle consists of 4-6 nearly equal rings, is erecto-patent, taper- 
ed slightly and terminated with a bell-shaped cell, perfectly transpa- 
rent and entire. The vesicles are matured in spring : they originate 
from the incrassation of the joints at the side of the cells, and re- 
semble an elegant Greek vase or urn, being of an elliptical or ovate 
shape, with a very short tubular opening on the flattened apex. The 
ova are comparatively large. 
The polypidom is occasionally tinted of a pink or rose-red colour, 
— an accident which is not unfrequent with the Sertulariadae in ge- 
neral, especially with Sert. abietina and pumila. On what the colour 
depends has not been ascertained. Some specimens so tinted retain 
the colour after being dried, while others lose it. The nature of the 
habitat has apparently no influence on it, for I have often observed 
coloured and colourless specimens on the same stone or sea-weed. 
3. L. gelatinosa, u subordinate branches dichotomously 
branched ; cells on twisted footstalks , campomulate , with even mar- 
gins” Ellis. 
Plate XXL Fig. 3, 4. and Plate XXIII. Fig. 1. 
Corallina filiformis ramosa pedunculis calyculorum contortis, Ellis , CoralL 
pb 38, fig. 3, and p. 23, pi. 12, fig. c, C. — Sertularia gelatinosa, Pall 
Elencb. 116. Stew. Elem. ii. 444. Hose, Vers. iii. 112. Fleming in 
Edin. Phil. Journ. ii. 84. Flem. Phil. Zool. ii. 616. pi. 5, fig. 3 
Campanularia gelatinosa, Flem. Brit. Anim. 549. Johnston in Trans. 
Newc. Soc. ii. 254. Sertularia dichotoma, in part, Lister in Phil. Trans, 
an. 1834, 372, 375, pi. 10, fig. L — Laomedea gelatinosa, Corallina, 92. 
La L. gelatineuse, Blainv. Actinol, 475 — La Sertolara dictoma, Cavol. 
Pol. mar. 194, tav. 7, fig ' 5 — 8, 
Hah. On stones between tide marks. “ Very common in the 
Tay above Ealmerino, towards Flisk beach,” Fleming. In Berwick 
Bay, abundantly, G. J. 
