102 NATURAL HISTORY OF 



stem, but are bound together by a spongy mass, in 

 which the calycles are plunged^ as it were^ for a con- 

 siderable portion of their length. This mass adheres 

 to the surface, and often encrusts the stem of various 

 Sertularian zoophytes." — Hineks. The mass of the 

 zoophyte is of a greenish-yellow colour. The calycles 

 are like those of L, diimosa, but they are provided with 

 an operculum. 



FAMILY VII. HALECIID^. 



Calycles biserial, suhsessile, jointed to a lateral process 

 from the stem. Polypites partially retractile. — T. H. 



Genus I. Halecium, OTcen. 



Zoophyte plant-like, more or less branched, rooted 

 by a creeping stolon, Calycles tubular or deeply cam- 

 panulate. Polypites large and fusiform. Reproduction 

 by means of fixed sporosacs. — T. H.* 



1. H. HALECiNUM, Linn. Plate V. fig. 2. 



Sertularia halecina {Linn., Pal., Esper, E. and 8., 

 Miiller, Fabr,, Turt., Bosc, Stew., Temp., Lamh., Flem.), 

 Thoa halecina [Lamx., Be B., O. J., B. Q. C). 



Hab. : Very common. Height 4 — 10 in. 



This is the " Herring-bone Coral " of Ellis. Its stiff, 

 coarse appearance is shown in the figure. The main 

 stems are compound and spring from a sponge-like, 

 fibrous root. The zoophyte gradually tapers to a point. 

 The calycles are alternate and tubular. The branches 



* Prof. Allman (Q. J. M. S., xiii. 55) states that In this genus 

 proper hydrothecse or calycles are suppressed, and that the sporosacs 

 are modified segments of the stem. He applies the name hydro- 

 phore to the portions of the stem which support the polypites 

 (" Gulf-Stream Hydroids," ]5). 



