SERTULARIADiE : SRRTULARIA. 75 



alternate, rather distant, either simple or semipennated with se- 

 condary shoots. The cells are of a thin transparent corneous 

 texture, large, smooth, exactly opposite, in approximated pairs, 

 divided by a strictured joint, the upper half free and divergent, and 

 the margin of the aperture uneven and obsoletely tridentate. Vesi- 

 cles large, unilateral, scattered, obcordate or pyriform with a tubular 

 aperture. It seems that the little spine on each side is dependant 

 on the age of the vesicle, and not perceptible when this is young. 

 When mature it is filled with orange-coloured ova. — In the thin 

 texture of the polypidom generally, and in the form of its cells, this 

 species resembles Sert. rosacea ; but its robust habit, and the man- 

 ner of its branching, give it at least equal claims to affinity with the 

 following. 



When highly magnified, the walls of the cells appear sometimes 

 to be regularly scored with fine transverse lines ; and on others 

 there is occasionally an irregular vascular network. These mark- 

 ings are not constant, and the latter is probably produced by the 

 inosculations of some minute parasite. 



13. S, ABiETiNA, cells nearly opposite or suhalternate, ovato- 

 tubular^ the mouth entire ; vesicles oval. 



Plate XIII. Fig. 1, 1. 



Abies marina, Ger. emac. 1574, fig. SiJtbald Scot. ill. lib. quart. 55. Merr. Pin. 1. 

 CoraUina marina abietis forma, Rail Syn. 35, no. 12. Bast. Opusc. Subs. 41. 

 tab. 2, fig. 6; and tab. 7, fig. 1—3, pessimae.— Muscus marinus major argute 

 denticulatis, Phmk. Phytog. tab. 48. fig. 5. Rail Hist. i. 78.— Muscus maritimus 

 filicis folio, Morris. Plant. Hist. iii. 650, tab. 9, fig. 1.— Sea-fir, Ellis Corall. 4, 

 no. 2, pi. 1, fig. b. B.— Sertularia abietina, Lin. Syst. 1307. Pall. Elench. 133. 

 AMI. Zool. Dan. prod. 255. Ellis and Soland. Zooph. 36. Esjxr Pflanz. Sert. 

 tab. 1, fig. 1, 2. Lam. Anim, s. Vert. ii. 116 : 2de edit. ii. 141. Risso, L'Europ. 

 merid. v. 311. Lamour. Cor. Flex. 189. Johnston in Trans. Newc. Soc. ii. 256. 

 TemiMon in Mag. Nat. Hist. ix. 468. Hassall in Ann. and Mag. Nat. Hist. vi. 

 168. Couch Zooph. Comw. 9 : Com. Faun. 22.— Dynamena abietina, Flem. Brit, 

 Anim. 543.— La Sertularie sapinette, Blainv. Actinolog. 480, pi. 83, fig. 6. 



Hah. — On shells and stones in deep water, common. 



" This elegant coralline is frequently found on our coast, adhering 

 by its vermicular tubes to most kinds of shells : it grows very erect, 

 and is frequently infested with little minute shells called Serpulas." 

 ^;?is.— Polypidom from four to twelve inches high, of a yellowish 

 horn colour, smooth and varnished, stout, regularly pinnate, the 



