NATURAL HISTORY SOCIETY OF GLASGOW. 55 



crawls along by the tentacles, and the posterior half of the body 

 is often held upright, or nearly so. Like other species of this 

 genns, it is very j^rone to break into pieces. 



Mr Eobertson informs me that this species is Synapta tenera, 

 one of his numerous additions to the marine fauna, and was 

 named by the Eev. A. M. Norman in a paper read before the 

 British Association in 1863, although no description is given in 

 the notice in the Eeport of that meeting.* 



An examination of the anchor plates in the drawing sent round, 

 as compared with Mr Herapath's plate of the known British species, 

 will show how distinctly the anchor process of this species and 

 the form of plate differ from those represented. 



Messrs Woodward and Barrett, in their paper on S. digitata and 

 S. inhcBvens, (reported in the Annals and Mag. of Natural History, 

 Vol. iii., 1859,) consider these plates as fully reliable for specific 

 characters, and that opinion is borne out by the plates of this 

 species. I have not yet met with S. digitata in Rothesay Bay, but 

 Messrs W. and B. state it was obtained there by the late Mr Alder 

 in 1844. 



IV. — In conclusion, two Serpulse are exhibited. 



Serpida Berkeleii (Johnston) usually occurs singly by itself on 

 a stone, and does not form a cluster like many of the other species. 

 It forms a hard, semi-transparent, j^orcellaneous looking tube, very 

 different in apparent consistency from the others. It rises up and 

 projects freely from the attached portion, and is terminated by 

 three well-defined sharp mucros; one or other of the points, 

 however, is often broken, probably the result of capture. The 

 operculum is of a fine orange colour; the stem is corrugated 

 and banded with orange red; the margin as well as the upper 

 surface is smooth. There is a narrow black ring inside, which 

 perhaps is caused by dirt. The branchial plumes are of a pale 

 greenish yellow, Avith an orange band across the middle. This 

 species is comparatively rare. 



S. reversa (Montagu), on the other hand, aj^pears to be very 

 common. It has a double operculum; the upper one rises out of 

 the centre of the lower, and has the margin armed with thorny 

 spines; sometimes they are single, but usually have one or two 



* It has since been described, with a plate, by Messrs Brady and Robertson, 

 in the Proceedings of the Zoological Society of Loudon, Nov. 21, 1871. 



