SERTULARIAD.E : SKRTULARIA. G3 



and shrubby habit, with numerous compound branches, — evi- 

 dencing the genial influence of climate on the growth and ap- 

 pearance of these corallines. 



In an examination of an extensive series of specimens, I have 

 found a considerable variety in the form of the cells and in the 

 degree of contraction at the aperture, and this even in the same 

 specimen, so that I am now led to regard M. Edwards' attempt to 

 draw a distinction between the specimens figured by Ellis as fruit- 

 less and unnecessary, and this conclusion I find confirmed by the 

 experience of Mr.W. Thompson and Mr. Peach.* The denticles on the 

 rim of the aperture are sometimes obscure, or even wholly absent ; 

 and I have seen specimens in which there was no joint between the 

 cells, but the tube was even and continuous, as represented by Ellis 

 in pi. 38. Smooth and strongly wrinkled ovaries have also oc- 

 curred on the same polypidom. Mr. Thompson says, " All the 

 specimens, from various localities, in my collection, whether growing 

 in a flexuous or erect form, winding round the stems of algpe, or 

 expanding in an arborescent manner from a single base, have both 

 cells and vesicles toothed. I have not seen any vesicles with an 

 even orifice, as represented in the erect state of the species by Ellis." 



In the collection of the British Museum, I saw our var. a. named 

 Sert. denticulata by Colonel Montagu ; and our var. ft. was his Sert. 

 polyzonias. The latter again is very well described and figured by 

 Lamouroux, under the name of Sert. Gayi. 



Esper's figures are not good, but still there can be no doubt that 

 they represent this species. 



2. S. RUGOSA, cells ovate, wrinkled transversely/, the mouth 

 narrow, with four small teeth on the rim. Ellis. 



Plate X. Fig. 4 — 6. 



Snail trefoil Coralline, Ellis CoraU. 26, no. 23, tab. 15, fig. a, A. — Sertularia nigosa, 

 Zire. Syst. 1308. PaZ^. Elench. 126. Ellis a.nA Solmid. Zoovh. 52. /air. Faun. 

 Groenl. 443. Esper Pflanz. Sert. tab. 11, fig. 1 — 4. Lam. Aiiim. s. Vert. ii. 

 121 : 2de edit. ii. 149. Flem. Biit. Anira. 542. Johnston in Trans. Newc. See. ii. 

 257, pi. 11, fig. 3. Couch Zooph. Corn. G ; Com. Faun. iii. 18. — Clytia rugosa, 

 Lamour. Cor. Flex. 204. Templeton in Mag. Nat. Hist. ix. 466. — La Campanu- 

 laire rugueux, Blainv, Actinol. 473. 



Hah. — Parasitical on Flustrce, Sponges, and Fuci at low-water 

 mark, common. 



* Mr. Thompson has seen Ellis' specimens, and he is of opinion that they belong 

 to Sert. polyzonias. The figures in Ellis' work admirably represent the specimens. 



