88 



broad anteriorly and narrow posteriorly. In the male, more- 

 over, the resemblance between the species is slight, the elongated 

 body gently tapered from front to rear having little resemblance 

 to the male of that from South Africa, It may be that two 

 parasitic crustaceans occur in Europe, and that the present 

 .species agrees with one of them, but no evidence on the subject 

 has been found. These crustacean parasites of Annelids- 

 approach in a close manner those of various fishes, e.g., such as 

 Boiiiolocliiis,-dve of the Ergasilidae, parasitic on the sole and the 

 ling. 



The female (Plate IX fig. 56) is about 1.2 mm. in length and 

 in general outline resembles an Eri^asilns, often seen on Doris 

 tiihcfciil/itd, hcixmg an ovate body (cephalothorax, Claparede) 

 to which is appended the tapering tail. The anterior end is 

 shaped like a hoof and the first segment is distinguished from 

 the rest by a lateral peak on each side. The second segment is 

 somewhat less in transverse diameter than the body at the peaks ;. 

 in antero-posterior diameter it is wider than the two following, 

 and the last segment is still less. A lozenge-shaped segment 

 follows with a few hairs at each lateral peak ; and this is 

 succeeded by a larger ovigerous segment from which the bulky 

 ovisacs extend. Four progressively diminishing caudal seg- 

 ments occur posteriorly, and to the last are attached the two- 

 caudal processes with long spines. The first of these segments 

 in the male especially appears to be more or less fused with the 

 genital segment. A lozenge-shaped greenish or brownish opacity 

 occurs in the centre of the carapace in some and is probably 

 due to the food. 



The antennules (Plate IX fig. 53) are of average length and 

 have seven segments, the second being the longest and the last 

 minute. They have similar hairs to Claparede'sS<^//)r////>//////5Sc/r,s/7'* 

 from SpirogiripJiis. The antenniv are shorter than in the latter 

 species, and have only two terminal hooks, and these do not 

 seem to be so closely parallel as in Claparede's form. The buccal 

 appendages appear to be similar to those of the latter. Dr. 

 Thomas Scott, who, along with Prof. G. S. Brady has done so 

 much good work in the group, kindly examined this form, "which 

 has a general resemblance to BoiiioIoLiiiis, though it belongs to 

 the closely allied family Lichomolgidti). The appendages of 

 the mouth in the latter are very well described and figured in 

 the 3rd volume of Prof. G. S. Brady's Monograph, and if the 

 drawings be compared with the corresponding appendages of 

 Boiiiolocliiis given in my paper in last year's Report of the 

 Fisliery Board for Scotland, a marked difference between them 

 will be noticed, especially in the structure and armature of the 

 mandibles and maxilhi'. On the other hand there is among the 

 genera composing the Lichomolgida? a certain similarity in 



* Op. cit. 



