Gatlj Marine Lahoratory , St. Andrews. 57 



tulea rather tlian under the Syllids. It has capillary dorsal 

 and jointed ventral bristles. The author alludes to its rela- 

 tionship with Acrocirrus frontifilis oi jMarioii and Bobrctzky. 

 He characterizes the <;^enns thus : — Cirratulids with lateral 

 branchise in several anterior segments ; a ])air of antenn?e 

 on the head. Peristoinium without appendages. His ex- 

 amples ranged fioni 0"75 to l"0 cm. and ha 1 thirty-two seg- 

 ments. Head and first six segments with brown corpuscles 

 in the skin, and the body covered with small papillae. 

 Head with a median process anteriorly, twoclavate anlennse, 

 and four eyes arranged in a curve from side to side, the larger 

 being external. Segments 2 to 5 with long, slightly clnb- 

 shaped branchiae. Dorsal bristles begin on the fourth seg- 

 ment (of the body), and the ventral division has jointed 

 hooks. Anal segment rounded, without appendages. Pro- 

 boscis unarmed. Eggs brownish yellow. 



Caullery and Mesnil ■^ (1898), who received a specimen 

 0"60 mm. long, collected by Langerhaus, from Marenzeller, 

 point out that the long bristles are spinose and much 

 resemble the temporary bristles of the pelagic larvae of 

 Spionids and Sabellarians. They think it a pelagic animal 

 and similar to the genera Tharyx and Chcetozone, and, 

 further, as a fixed epitokous form. Acrocirrus (A.frontifilis 

 and A. validus) present analogous features. On the other 

 hand, hedon sexuculata, Webster and Benedict, has in the 

 dorsal division of each foot capillary bristles 060 mm. long; 

 they point out the identity of the hooks with those of 

 Acrucirrus. 



Mr. Southern f, to whom I am indebted for an examination 

 of the annelid, considers that its systematic affinities are 

 at present not clearly recognized. He adds, '' that the rela- 

 tion to the Syllidae is very slight, whilst that to the Cirratu- 

 lidae is not so pronounced as (Jaullery and JNlesnil maintain." 

 He procured examples in Blacksod Bay in weeds from rock- 

 pools, in Laminarian roots, and with weeds in 1-4 fathoms ; 

 and by the dredge in Clew Bay and Ballynakill Harbour in 

 a few fathoms. 



EXPJ.ANATION OF THE PLATES. 

 Plate I. 



Fig. \. Tube of Cistenides hyperhorea, Mahngren. Enlarged. 

 Fiy. 2. Portion of the sanit^, still furlher enlarged, to show the grains, 

 nineteen to twenty-two of wliicb occur at the wider end. 



* Annales Univ. Lyon. fasc. xxxix. p. 130. 



t Proc. Pioy. Irish Acad, vol. xxxi. no. 47, p. 120. 



