Gatty Marine Lahoniiorij, St. Andrews. 97 



a couical anterior fold, the tentacles with their plate o£ 

 insertion being drawn inward, the parts in the respective 

 conditions being clearly shown in FauvcPs figures *. Some 

 preparations thus show an outer and an inner folded collar. 



The second segment is short and devoid of processes. 

 The third bears dorsally the fan of flattened paleae, and 

 with the next segment (Fauvel) the four branchiae on each 

 side. The palere form a more or less horizontal fan with 

 the longer bristles internal, the shorter external. Each of 

 the larger paleaj has a flattened finely striated shaft and a 

 tapered tip with a granular interior and a slender curved 

 tip ending in a tine point, the same minutely granular 

 aspect being present in it as in the region below. The 

 concave edge of the distal curve is crenulated, after the 

 manner of similar structures in the Amphictenida3. 



The branchi* are smooth or slightly crenulate tapering 

 organs of a greenish hue, which arise three in a transverse 

 row on the third segment and the fourth behind the middle 

 one of the row. 



The anterior region is distinguished by the ventral 

 glandular belts and by the presence of fourteen setigerous 

 lamellae and fourteen lamellae for the hooks. Whilst two 

 or three of the anterior lamelke for the bristles are smaller, 

 the typical process is somewhat flattened and carries the 

 row of bristles more or less vertically, the longer and 

 stronger bristles being dorsal, the somewhat shorter ventral. 

 Each bristle has a bulb at its origin, then the shaft dilates 

 a little, remains of equal diameter for some distance, then 

 shows a slight curvature at the commencement of the tip, 

 which has wings and tapers to a hair-like point. About 

 eight of the stronger forms are present in each tuft, besides 

 a series apparently of developing forms, the sleuder tips of 

 which project between the others at the level of the skin. 

 A tendency of the upper tips to bend downward and of the 

 inferior upward is often apparent. 



The lamellae or ridges for the hooks lie ventralwards of 

 the bristles and anteriorly form ridges with an even margin, 

 but by and by a papilla appears at the dorsal edge and forms 

 toward the end of the region a cirrus with a slender tapering 

 extremity, not shown by Fauvel. The anterior hooks differ 

 from the outlines of Fauvel, having a broader body, about 

 six teeth, and a rounded prow of a different curvature from 

 that figured by the French author. 



The posterior region has twelve segments and is dis- 



* Op. cit. pi. xix. figs. 57 & 58. 

 Ann. cO Mag. N. Hist. Ser. S. \'ul. xiii. 7 



