252 SERTULAEILD.E. 



4. D. PINASTER, Ellis & Solander. 



SERTULARIA PINASTER, Ellis 8f Solander, Zooph. 55, t. vi. fig. 6 B ; Johnxt. 



B. Z. 71, 72, fig. 12 a,b; Alder, Northumb. Cat. in Trans. 



Tynes. F. C. iii. 114. 



DYNAMENA PINASTER, Lamx. Exp. Meth. 12, t. vi. figs, b, B. 

 DIPHASIA PINASTER, Agassis, N. H. U. S. iv. 355. 

 SERTULARIA MARGARETA (the female), Hassall, Ann. & Mag. .N. H. vii. 284, 



pi. vi. figs. 3, 4 ; Johnst. B. Z. 72, 73, fig. 13 ; Hincks, Devon 



and Cornw. Cat., Ann. N. H. (3rd ser.) viii. 254. 

 DIPHASIA MARGARETA, Agassiz, N. H. U. S. iv. 355. 



Plate L. fig. 1. 



STEMS erect and somewhat rigid, regularly pinnate ; pinna? 

 alternate, often of great length, with occasionally a few 

 hranchlets ; HYDROTHEC.E tubular, the inferior half adhe- 

 rent, the superior abruptly divergent and slightly curved 

 upwards, with a distinct fold at the point of divergence ; 

 aperture plain and circular; GONOTHEC^: (male) ovate, 

 subpedicellate, quadrangular above, each angle produced 

 at the top into a spine ; (female) oval, shortly stalked, 

 domed above, with four longitudinal ridges and eight 

 spines borne on the ridges and arranged in two circles, 

 one near the top and the other somewhat lower down. 



Two species have been made out of this well-marked form, 

 founded on mere differences of sex, which had not been 

 recognized when Dr. Johnston's work was published. The 

 Sertularia Margaret a of Hassall is the female of the S. 

 pinaster described and figured by Solander. This species 

 is of somewhat rigid habit, and, when dried, of a light 

 horn-colour. When fresh it is of a delicate pearly white- 

 ness, and when laden with the yellow capsules, which 

 stand erect in rows along the pinna?, is a most beautiful 

 object. The creeping stem sends up pinnate, plume-like 

 shoots from 2 to 6 inches high, that are either single or 

 bear similar shoots at irregular intervals, which, as Dr. 

 Johnston well said, " appear rather to grow on the rachis 



