i66 



DISCOVERY REPORTS 



Genus Ophelia, Savigny 

 Body divided into two distinct regions, an anterior cylindrical region and a posterior 

 region with a deep ventral and two lateral grooves. The head is a small pointed cone 

 with two or three eyes beneath the skin. The segments are divided by superficial rings. 

 Cirriform branchiae are present on all segments except about the first lo and a few 

 terminal segments. Notopods and neuropods are represented by small bundles of 

 capillary bristles and sometimes by a pair of low rounded lobes. A lateral organ is 

 present between the two rami, and the anal segment carries papillae. 



Ophelia bipartita, n.sp. (Fig. 29 a, b). 



Occurrence. St. WS 742 (4). 



Description. A rather massive species. The number of chaetigers is 31, and the 

 largest specimen measures 63 mm. by 7 mm. at the widest part. The colour in spirit is 

 grey. The body is very sharply divided at the 8th chaetiger into two distinct regions 

 (Fig. 29 a), as in the Thoracophelia of Ehlers, an anterior region of eight chaetigers 

 without a ventral groove and a posterior region of 23 chaetigers with a profound ventral 

 sulcus. The prostomium is a small, pointed cone. The branchiae begin at the loth 

 chaetiger and there are 17 pairs. Those in the middle of the body are long enough to 

 meet across the back and all are crenate. The last five chaetigers are abranchiate and the 

 last four have specially long bristles and are involved in the anal region. 



■5 MM 



Fig. 29. Ophelia bipartita. 

 a. Anterior region of body seen from side. b. Anal cylinder seen from behind. 



The anus (Fig. 29 b) has a pair of stout anal papillae, which are continuations of the 

 lateral ridges, and above these 16 slender papillae. Inside the rectum is a papillated 

 valve. There is a lateral organ in the form of an oval pore between notopod and neuropod 

 in every chaetiger, and nephridial pores are present from the 12th to the i6th chaetigers. 



This species then has a very clearly separated anterior region of eight chaetigers, the 

 first nine and the last five chaetigers abranchiate and an intermediate branchiate region 

 of 17 chaetigers. 



Remarks. This species is very close both to the European O.neglecta, Schneider, and 

 to the South Australian O. damievigi, Benham. O. Jieglecta has 32 chaetigers and 18 

 pairs of branchiae. Moreover, the ventral groove begins at the loth chaetiger and not 



