Dr. Johnston's Catalogue of Zoophytes'. 259 



jointed, clothed with compound branches, which come off in such a manner that four or five 

 of them form a spiral whorl : they are short, spreading, and somewhat arched, panicled, 

 and dichotomously divided. Cells semi-alternate, each pair generally separated from the 

 others by the intervention of a joint. Vesicles scattered irregularly, urn-shaped, with two 

 teeth at the extreme angles. 



In small specimens the branches are simple and almost bifarious ; and in these the cells 

 on the stem are very distinct, but the stem of full grown specimens is perfectly smooth. 



The specimens from which this description is taken resemble exactly the figure of Ellis 

 quoted among our synonymes, but the ovarian vesicles are like those of his Sertularia cu- 

 pressina, t. iii. No. 5. This fact affords a strong argument in favour of the opinion of those 

 naturalists who believe these species to be mere varieties. 



9. S. halecina, stem compound, irregularly branched ; branches bifarious, erecto-patent, 

 pinnate ; pinnae spreading, alternate ; cells unilateral, biserial, alternate, tubular, with 

 a wide aperture ; ovarian vesicles large, tubular, with a contracted neck and mouth. 

 Herring-bone Coralline (tab. nost. xii. fig. 2). 



S. halecina, Linn. — Soland. Zooph. 46 ; Turt. Lin. iv. 678 ; Turt. Br. Faun. 213 ; Stew. 

 Elem. ii. 442 ; Lam. Hist. Nat. ii. 119 ; Bosc, Vers, iii. 109 ; Hogg's Stockton, 32 ; 

 Flem. Br. Anim. 542. 



Thoa halecina, Lamour. Corall. 93. 



Herring-bone Coralline, Ellis, Corall. 17, t. x Phil. Trans, xlviii. 506, tab. xvii. fig. E. 



Corallina scruposa pennata, Rail Syn. 36, No. 15. 



Hab. On old shells, particularly on Buccinum undatum. 



Stem tapering, composed of several tubes adhering together, generally encrusted with 

 foreign matter. The cells are not confined to the pinnae, but are placed also on the 

 branches ; they are small and depressed. Our specimens from the Durham coast are re- 

 gularly pinnated, and branched in a manner different from that represented by Ellis, but 

 the cells and ovarian vesicles are precisely the same. It might, with greater propriety, be 

 placed in the genus Plumularia. 



10. PLUMULARIA. 



1. P. falcala, stem rising in wide spiral turns, cylindrical, simple or compound, branched ; 

 branches placed one above the other on the outer side, spreading, pinnate ; pinnae al- 

 ternate, bifarious ; cells small, unilateral, biserial, alternate, tubular with prominent 

 mouths. Sickle Coralline. 



P. falcata, Lam. Hist. Nat. ii. 125 ; Flem. Br. Anim. 546. 



Sertularia falcata, Linn. — Soland. Zooph. 42 : Turt. Lin. iv. 679 ; Turt. Br. Faun. 213 ; 

 Stew. Elem. ii. 443; Bosc, Vers, iii. 110 ; Hogg's Stockton, 32. 



Aglaophenia falcata, Lamour. Corall. 77. 



Sickle Coralline, Ellis, Corall. 12, t. vii. No. 11, f. a. t. xxxviii. f. 6. 



Corallina muscosa pennata, liaii Syn. 36, No. 16. 



Hab. On shells, &c. in deep water. 



