Gatbj Marine Laloratory , St. Andrews. 27 



of five (Claparede) and similar in general appearance. 

 They are ciliated internally and have palpocils externally. 

 The first ventral branchia is rednced to a simple filament 

 without pinnae. A single vessel occurs in each filament, 

 aud it ends blindly where the cilia cease. 



The bodi/ of the examples from Sark is not larger than 

 that of Amphicora fabricia from St. Andrews — the advantage 

 in size, indeed, being with the northern form, which is also 

 more translucent. The eyes had disappeared in the pre- 

 j)arations (after preservation for 42 years), and yet, as 

 Claparede shoAvs, those of A. fabricia are permanent in 

 spirit. The nnmber of segments is at once diagnostic, for 

 Oria armandi has fourteen bristled segments besides the 

 first and last. Claparede, however, gives nineteen or twenty 

 segments, though he found a ripe female with fewer than 

 twelve segments. The first segment is achetous. At the 

 tenth segment the bristles change to the ventral border and 

 the shape differs. 



Tlie digestive system has a cylindrical colourless oesophagus, 

 and from the third segment the gastro-intestinal canal 

 proceeds backward as a brownish wide tube. A blood-vessel 

 runs on each side of the canal with a transverse branch in 

 each segment — indeed, the gut is surrounded by a vascular 

 rete {C/aparede). In the seventh segment a pair of folded 

 tubular organs (segmental?) occur. 



Fourteen pairs of bristle-bundles characterize those from 

 Sark. The anterior bristles have stouter shafts than those 

 of Amphicora fabricia, and the tapering tip is shorter and 

 has wider wings. Eight pairs belong to the anterior and 

 six to the posterior region, the latter being distinguished by 

 their slenderuess and the tenuity of their hair-like tip, as 

 well as by the absence of wings. Moreover, they are 

 generally directed forward with a slight curvature, whilst 

 the anterior bristles are directed backward. The anterior 

 hooks have a similar shape to those of Amphicora fabiicia — 

 that is, have a curved shaft which tapers interiorly, a 

 shoulder above which is a somewhat narrower neck 

 surmounted by a strong sharp main fang, which comes off at 

 less than a right angle to the throat and with two or three 

 strong teeth above it, the crown being, on the whole, more 

 elevated than in A. fabricia. The neck of the hook is also 

 slightly bent backward. The posterior hooks, which, as in 

 Amphicora fabricia, occur in the last three bristled segments, 

 differ, as Claparede observed, from those of the species just 

 mentioned in their shorter form, for the basal region is 

 truncated aud the posterior outline short and concave, the 



