194 Prof. MIntosh’s Notes from the 
met with Folliculina ampulla in the interior of a tube and 
the ova of Automolos unipunctatus, Graff (Monocelis uni- 
punctatus, CErst.), and Turbellarians are not uncommon in 
tubes from St. Andrews and Lochmaddy. 
The next, or thirteenth, species, which was probably included 
by Sacchi as Serpula spirorbis in his ‘ Catalogue of the Shells 
of Naples,’ has been well known since Claparéde described 
it as Pileolaria militaris in his volume on the Annelids of 
Naples. It is a southern type and, so far as known, has 
hitherto been confined in the British area to the Channel 
Islands, though Caullery and Mesnil found it not infrequent 
on the shores of France, and Langerhans mentions a form 
(his Spirorbis granulatus, L.) which these authors consider to 
be only a variety from Madeira. It is rarely met with in 
the Channel Islands. 
The operculum is comparatively large, helmet-shaped, and 
ornamented with denticulated ridges and accessory pro- 
cesses. The cavity of the helmet performs the function 
of a brood-pouch, and, in those captured in July and August, 
was filled with large eggs and embryos—the breeding-season 
at Naples being somewhat earlier, viz.,in June and July. 
It differs from such as Spirorbis pagenstecheri, De Quatre- 
fages, in so far as the opercular helmet is ready to receive 
the ova without further addition or alteration. Its specific 
name has reference to the helmet-like condition of the 
operculum, which is ornamented with characteristic ridges. 
The branchie have comparatively thick filaments which 
end in along and slender process. The body is typical in 
outline, has a deep reddish hue, and the same colour tinges 
the branchiz, the collar, and the anterior membrane (Caul- 
lery and Mesnil). Anterior region of three-bristled segments. 
The first or collar-bristles are characterized by their size, 
the coarseness of their serrations, the presence of a distinct 
gap, and their yellow colour. Moreover, they are boldly 
curved at the tip, so as almost to resemble “ kneed ” bristles. 
They are accompanied by a series of simple bristles, which 
are widest, though they do not quite reach the size of the 
former bristles, at the base and gradually diminish to a 
delicate hair-like tip. The next bristle-tuft has capillary 
bristles with finely serrated rings, the shaft in each being 
nearly cylindrical or very slightly tapered. 
The sixth species of Spirorbis is one originally described 
by Miss Pixell from the shores of British Columbia, and 
which Mr. Southern procured in Blacksod Bay on the West 
Coast of Ireland, and I am indebted to him for examples. 
