SERTULARELLA TRICU SPED ATA. 239 



on the margin, instead of tlie four teeth which occur in 

 the preceding species. The ringing, which is very marked, 

 covers only the upper third of the capsule, the inferior 

 portion being perfectly smooth. 



S. Gayl ranges in height from about 4 to 10 inches. It 

 is a deep-water form. Pallas describes it, under his S. 

 ericoides, as " elegantissimam omnium varietatem." 



Hub. Cornwall, not uncommon; climbing over Gor- 

 gonia, from 60 fathoms, off the Deadman; amongst the 

 refuse of the Plymouth trawlers (T. H.) : Isle of Wight 

 (Solander) : Norfolk and Suffolk (C.W. P.) : Durham and 

 Northumberland, occasionally in deep water (J. A.) : Pe- 

 terhead and Wick (C. W. P.) : Shetland (A. M. N.) : 

 Birterbuy Bay, Comiemara (G. S. Brady) : Dublin Bay. 



[Coast of Normandy (Gay).] 



3. S. TRICUSPIDATA, Alder. 



SERTULARIA TRICUSPIDATA, Alder, North, and Durham Cat. in Trans. Tynes. 



F. C. iii. Ill, pi. iv. figs. 1, 2. 

 ERICOIDES, Espcr, Pflanzth. Sertul. pi. xii. figs. 1, 2. 



Plate XLVII. fig. 1. 



STEMS slender, alternately branched, or divided dichoto- 

 mously, often bipinnate at the top, jointed above each 

 calycle, and twisted at intervals ; HYDROTHEC.E distant, 

 cylindrical, smooth, slightly expanded and everted above, 

 with a 3-toothed aperture : GONOTHEC.E large, strongly 

 ribbed across, with a plain funnel-shaped aperture, which 

 rises from the centre of a bowl-like expansion. 



THIS species is separated from S. polyzonias by a group 

 of well-marked characters. It is of exceedingly delicate 

 habit, of a light brown colour, and attains a height of 

 about 2 inches. The mode of growth is irregular. Some- 

 times the branches are alternate, and often themselves 



