116 NATURAL HISTORY OP 



each wave, and there are four or five to each spiral. 

 These branchlets are divided and subdivided, and bear 

 alternate calycles which are pointed and turn a little 

 inwards " like the horns of a bull" {Ellis). These are 

 also borne on the main stem. When the zoophyte 

 exceeds 12 inches in height, the lower part of the stem 

 becomes bai^e. The interuodes of the branchlets vary 

 considerably, containing sometimes 2, sometimes 4, and 

 sometimes 6 calycles. The gonothec^ have a circular 

 aperture, and are surmounted by one or two spines. 



7. S, cuPRESSiNA, Linn. 



S. cypres {De B.), S. argentea {Dal.), Dynamena 

 cupressina (Flem.). 



Hab. : Widely distributed in deep water. Height 

 about 1 foot. Mr. Mcintosh has found at St. Andrew^s 

 a branched variety 18 in. high. 



This species has been often asserted to be identical 

 with the preceding. Pallas and Linnaeus regarded 

 them as the same, and Dalyell, Fleming, and Johnston, 

 wei'e inclined to agree with them. Dr. Landsborough 

 considered that they " ran into each other.''^ On the 

 contrary, Ellis, Hassall, Thompson, and Bean, con- 

 sidered them distinct, and in this opinion they are 

 followed by Mr. Hincks. 



S. cupressina, or the " Sea Cypress '' of Ellis, is much 

 stouter than S. argentea. The stem is thicker and the 

 branches longer and narrower. The branches are also 

 much lighter coloured. The calycles also are different, 

 having a bilabiate mouth (i.e. divided at the aperture, 

 so as to form two denticles) . There are usually three 

 pairs of calycles to each internode, although internodes 

 of the second, and even of the first or fourth order, are 

 found to occur. 



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