HALECITJM HALECINUM. 221 



the Campanularian group and the Sertulariidcs ; its caly- 

 cles are subsessile, and not let into the stem as in the 

 latter family. Its habit makes an approach to that of the 

 Campanulariidce ; while its large and scarcely retractile 

 polypites remind us of those of the Athecata. 



In some species, and possibly in all, the female capsule 

 exhibits a curious peculiarity, being surmounted at a 

 certain stage by two perfectly formed polypites which pro- 

 trude from the orifice, and are seen to be a continuation 

 of the column that traverses the cavity and bears the 

 gonophore. This is the only instance amongst the Theca- 

 phora in which the proliferous polypite is not permanently 

 atrophied and reduced to a mere columnar offshoot from 

 the coanosarc ; but amongst the Athecata it is commonly 

 fully developed, and the cases of partial or complete atrophy 

 are exceptional. These capsular polypites were first noticed 

 by Van Beneden on H. halecinum; they occur onH. Beanii; 

 and I have also found them on H. nanum, a species from 

 the gulf-weed described by Alder. 



The marked peculiarities of Halecium entitle it to be 

 made the type of a distinct family. 



1. H. HALECINUM, Linnfeus. 



"HERRING-BONE CORAL," Ellis, Corall. 17, pi. x. 



SERTULARIA HALECINA, Linn. Syst. 1308; Pall. Blench. 113; Esper, Pflanz. 



Sert. t, xxi. figs. 1,2; Lamk. An. s. V. (2nd ed.) ii. 146. 

 TIIOA HALECINA, Lamx. Cor. flex. 211 ; Blainv. Actinolog. 488, pi. Ixxxiv. 



figs. 4, 4 a. 

 HALECIUM HALECINUM, Schwcigger, Handb. 42fi ; Johnston, B. Z. 58, pi. viii. 



Plate XLTT. 



SHOOTS erect, of a rigid habit, irregularly branched, springing 

 from a sponge-like mass of fibres; STEMS compound, 

 made up of many delicate tubes, tapering upwards ; 



