796 PROCEEDINGS OF THE ACADEMY OF [DeC, 



are subcylindrical, but are somewhat constricted at the base and 

 tapered more or less distally, thin-walled and hollow, with less trans- 

 parent integuments than the body. Typically they are of large size, 

 many of them much exceeding their parapodia, which they may 

 totally conceal from above. The second (on somite VI) is the largest, 

 being twice as long and much thicker than the corresponding para- 

 podiimi. The next two are successively slightly shorter; and from 

 this point to near the posterior end large and small cirri regularly alter- 

 nate, short ones whose ceratophores barely equal the parapodia occur- 

 ring on XII, XVI and XX, long ones with ceratophores much exceed- 

 ing the parapodia on XIV and XVIII, that of XXII, though of 

 reduced size, also belonging to the latter group by reason of its long 

 style. On XXIV the dorsal cirri arc greatly reduced. The styles are 

 slender and tapering to the ends, those of the larger cirri being whip- 

 lash-like and from Ih times to twice the length of the ceratophores, 

 and the smaller ones little exceeding their ceratophores and apparently 

 more rigid. The style on XXIV is conical, that of XXV short ovate. 

 Whether somite XXVI bears a cirrus or an elytron is uncertain, as 

 only a small tubercle is present. 



Twelve pairs of elyt,rophores occur on somites II, IV, V, and then on 

 every alternate somite to XXIII inclusive, and the small tubercle on 

 XXVI may possibly indicate a thirteenth. The elytrophores are 

 remarkable for their length and slenderness (figs. 3 and 4). In the 

 alcoholic specimen they are much contracted, as indicated by the 

 \\Tinkles, furrows and nodules upon their surfaces, particularly of the 

 last two. When the specimen was first taken they were extended, 

 and the parapodia were raised high above the body. The elytra are 

 attached near the middle by a very limited area, and are readily 

 detached. They are perfectly plain and smooth, without papillae, 

 cilia or processes of any kind, or any pigment. Instead of having the 

 usual scale-hke form, the elytra, when the specimen was taken from 

 the tow-net and still alive, were inflated and spherical, being mere thin- 

 walled vesicles filled with fluid, but certainly entirely closed and without 

 any communication with the coelom. That this condition may have 

 resulted from rough handling in the net is possible, but seems improb- 

 able from the fact that every elytron is in the same condition. An 

 area surrounding the scar of attachment is finely granular; elsewhere 

 the el5d:ron is perfectly transparent. A large part of the back is 

 exposed, the elytra having the aspect of a series of floats attached along 

 its sides. 



Typical parapodia bear seta; of two kinds, the one elongated and 



