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. geniciilee, Blainv. Actinol. 474 Campanularia 



geniculata, Flem. Brit. Anim. 548. Johnston in Trans. Newc. Soc. ii. 

 235. 

 Hab. Parasitical and gregarious on sea weeds that grow near low- 

 tide mark, especially on tlie frond of Laminaria digitata, very com- 

 mon. 



Polypidom attached by a creeping tulnilar 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 Sertulariadse 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. 



f5. L. GELATINOSA, " Sill) Ordinate branches dichotomously 

 branched ; cells on twisted footstalks^ companulate^ icith even mar- 

 gins." Ellis. 



Plate XXI. Fig. 3, 4. and Plate XXIII. Fig- 1. 

 Corallina tiliformis ramosa pedunculis calyeulonim contortis, Ellis, Corall. 

 pi. 38, fig. 3, and p. 23, pi. 12, fig. c, C. — Sertiilaria gelatinosa, Pall 

 Elench. 116. *S^ew. Elem. ii. 444. jBosc, 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 Scrtolara dictoma, Cavol. 



Pol. mar. 194, tav. 7, fig- '5 — 8. 



Hab. On stones ^tween tide marks. "Very common in the 



Tay above Balmerino, towards Flisk beach," Fleming. In Berwick 



Bay, abundantly, G. ./, 



