90 ANTHOZOA HYDROIDA. 



unilateral, usually seated in the axilla of a horny spine ; 

 vesicles scattered, unilateral. Polypes hydraform. 



* Stem a single tube. 



1 . P. FALCATA, stem waved, branched ; branches alternately 

 pennated ; cells close-ranked, shortly tubulous with a plain rim ; 

 vesicles oblong-oval, Merrett.* 



PLATE XXL Fig. 1, 2. 



Muscus marinim spiralis pennatus, Merr. Pin. 81. Corallina muscosa pennata, 

 ramulis et capillamentis falcatis, Rail Syn. i. 36, no. 16. Muscus pennatus, 

 ramulis et capillamentis falcatis, Pluken. Phytog. tab. 47, fig. 12. Muscus mari- 

 timus pennatus, ramulis et capillamentis falcatis, Morris. Plant, hist. Ox. iii. 650, 

 tab. 9, fig. 2. Sickle Coralline, Ellis Corall. 12, no. 11, pi. 7, fig. a, A. and pi. 

 38, fig. 6. Corallina erecta pinnata, Bust. Opusc. Subs. 41, pi. 2, fig. 5, male. 

 Sertularia falcata, Lin. Syst. 1309. Pall. Blench. 144. Ellis and Solaml. Zooph. 

 42. Esper Pflanz. Sert. tab. 2, fig. 1, 2. Berk. Syn. i. 217. Blumenb. Man. 

 273. Aglaophenia falcata, Lamour. Cor. Flex. 174. Plumularia falcata, Lam. 

 Anim. s. Vert. ii. 125 : 2de edit. ii. 160. Grant in Edin. New Phil. Journ. i. 

 155. Flem. Brit. Anim. 546. Johnston in Trans. Newc. Soc. ii. 259. H 'assail 

 in Ann. and Mag. N. Hist. vi. 169. Couch Zooph. Cornw. 14 : Corn. Faun. iii. 30. 



Hah. On shells and rocks near low-water mark, and in deep 

 water. 



A common and very elegant species, generally from four to 

 six inches in height, sometimes attaining to twelve, rising in wide 

 spiral turns, and sending out from its filiform percurrent stem, at 

 regulated intervals, alternate spreading plumous branches which 

 are placed one above the other on the outer side. Pinnae alternate, 

 bifarious. In young specimens the branches are two-ranked and 

 alternate, and I have seen this character remain in one specimen 

 of considerable size. There are no cells on the spiral stem, but 

 they occur on the branches as well as on the pinnae, and are ar- 

 ranged in two rows pointing alternately to opposite sides. There is 



Lamarck avait mis gen6reusement a sa disposition toutes les richesses de cet eta- 

 blissement deja denominees et classees par ses soins." Ann. des Sc. Nat. Part. Zool. 

 torn. vi. second ser. p. 12. 



* For an account of Dr. Christopher Merrett, see Wood's Athen. Oxon. v. ii. 

 p. 930 ; Pulteney's Sketches, v. i. p. 290, &c. ; and Thomson's Hist, of the Roy. Soc. 

 p. 22. He was born in 1614 ; was one of the original members of the Royal Society ; 

 and died in 1695. Ray's character of him in 1688 is" Annis et scientia gravis, de 

 Professione sua deque Repub. Botanica optime meriti." Hist. Plant, praef. Contrast 

 this with the character in Sir J. E. Smith's Eng. Flora, i. pref. vii-viii. Those who 

 care to study Merrett's character may, perhaps, find a key to it in the " Epistola ad 

 Lectorem" of the Pinax. 



