SERPULIDA. 325 
with the functions of the part. The other bristles of the abdomen range themselves under 
six types: 
1. Absolutely capillary :—Gen. Ditrupa, Hyalopomatus, Protis. 
2. Bayonet-like bristles with a striated margin simulating denticles:—Gen. Protula. 
3. Bristles with sickle-lke curved tips:—Gen. Spirorbis, Protula, Apomatus. 
4. Bristles more or less “kneed”’ (geniculate) and more or less denticulate on the edge :— 
Gen. Pilograna, Salmacina, Filogranula, Spirorbis, Pileolaria, Vernilia, Galeolaria’?, Omphalo- 
poma, Chitinopoma, Placostequs, A pomatus. 
5. Trumpet-like bristles (flattened) with serrated border:—Gen. Serpula, Hydroides, 
Crucigera. 
6. Trumpet-like bristles (flattened) with serrated border, which is prolonged into a 
tapered point:—Gen. Pomatocerus, Placostequs, Spirobranchus, Pomatostequs. 
It is clear that the various forms of bristles occur in allied genera and that other features 
require consideration, whilst the hooks remain fairly characteristic of genera. De St. Joseph 
therefore combines in his classification secondary characters with these, such as the form 
of the operculum, the presence or absence of a thoracic membrane, the branchie, tube (right 
or left spire) more or less coiled. His classification is :— 
A. Hooks with numerous teeth terminating anteriorly in a large tooth pointed like the 
others. 
I. Bristles of the first thoracic segment massive, with a long terminal region preceded 
by two short spikes or cones. Rest of the thoracic bristles wmged. Abdominal bristles 
compressed, trumpet-shaped, serrated distally, an operculum:—sSerpula. Operculum funnel- 
like, denticulate on the edge:—S.G. Serpula, s. str., Phil. Funnel-lke operculum, the centre 
of which is elevated by spines and bayonet-like pales :—S.G. Hydroides, Gunn. (Hupomatus, 
Phil., Hucarphus, Morch, Polyphragma, De Quatref.), Crucigera, no operculum, Benedict, 
Protis, Ehlers. 
Ii. Hooks with finer and more numerous teeth than the preceding—terminating 
anteriorly in a long tooth larger and more obtuse than the others:—EHx. Chatinopoma, 
Levinsen, Filograna, Oken, Salmacina, Clap., Filogranula, Langerhans, Spirorbis, Daudin, 
Pileolaria, Clap., Janna, De St. Joseph, Omphalopoma, Morch, Circeis, De St. Joseph, 
Omphalopomopsis, De St. Joseph, Janta, De St. Joseph, Leodora, De St. Joseph, Mera, 
De St. Joseph, Hyalopomatopsis, De St. Joseph, Vermila, Lamarck, Galeolaria, Lam., 
Vermiliopsis, De St. Joseph, Ditrupa, Berkley, Dasynema, De St. Joseph. 
III. Hooks with more or less numerous teeth, more or less fine, terminating anteriorly 
in a large spine, smooth dorsally, grooved like a gouge ventrally :—Ex. Pomatocerus, Phil., 
Spirobranchus, Blv., Pomatostegus, Schmarda, Placostequs, s. str., Placostegopsis, De St. Joseph. 
IV. Hooks with numerous and extremely fine denticulations deeply hollowed anteriorly, 
and terminating at the other extremity by a smooth spine (not hollowed), more slender and 
longer than in the type III:—Pvrotula, Risso (including Psygmobranchus, Phil.), Protula, 
s. str. (Protula tubularia, Mont.), Protulopsis (Protula intestinum, Mont.), Apomatus, Phil., 
Morch, and Apomatus, s. str. (A. globifer, Théel), and Apomatopsis, De St. Joseph (A. ampulli- 
formas, Phil., P. Marioni, Marenzeller, and A. Hnosine, Marenzeller). 
There is much that is of importance in De St. Joseph’s classification, and, though it has 
not been followed, his experienced remarks are in general both trustworthy and interesting. 
