Ueport on the Crustacea Schisopofla nf Ireland. 233 



The species is added to tlie British Fauna on the evidence of a single female, 

 so much battered that some of the generic characters cannot be observed. The 

 telson, however, remains available, and is of a form only met with, so far as we 

 know, in the genera Parerythrops and Metererythrops {vide figs. 2, 3). 



In distinguishing between the three known species, P. obesa, 31. robusta, 

 S. I. Smith, and P. ahyssicola, G. 0. Sars, the small size of the eyes in the last 

 named is a very obvious character. The two first have large eyes of about the 

 same size and form. So far as we can determine, in the absence of the adjacent 

 appendages, and from the defective condition of tlie cephalothorax, the eyes in 

 our specimen are too large to permit of its being assigned to P. ahi/ssicola. 

 Moreover, the outline of the facetted area agrees, on the testimony of Sars' figures, 

 rather with P. obesa tlian with P. abyssicola. While in other characters the latter 

 closely resembles P. obesa, 31. robusta differs from either in having a much more 

 elongate telson. In our specimen it is about equal to the last segment of the 

 abdomen ; in 31. robusta it is about one-third as long as the entire pleon. Minor 

 differences observed by Sars in the characters of the antennules, antenna! scales, 

 and legs are of no use to us, as our specimen has lost all these appendages. 



P. obesa and P. abyssicola are not separated by any very well-marked charac- 

 ters of the telson, but, although the lateral margins of this structure are rather 

 more curved than in Sars' figure of P. obesa, they agree with that species rather 

 than with P. abyssicola. The proportions of the terminal sjjines are also in 

 harmony with P. obesa rather than with P. abyssicola {cf. Sars, op. cit., PL in., 

 fig. 18, PL xxviii., figs. 9, 10, PL XXIX., figs. 7, 8). 



The single inner uropod which remained entire in our specimen was broken 

 in manipulation, but has been carefully reconstructed by Mr. Green (fig. 3). 

 At present it has fewer spines than in any of Sars' species, but some have almost 

 certainly been broken off. 



Genus Mysidopsis, G. 0. Sars. 

 Mysidopsis didelphys (Norman). 



Survey. — Station 115. Off the Skelligs, 62 to 52 fathoms, mud and sand. 

 August 20th, 1890. 



Station 125. 40 miles west of Bolus Head, 115 fathoms. March 23rd, 1891. 



We have already mentioned, under E. serrata, the accidental mixing of the 

 contents of the bottom and surface nets of Station 125. The bottle contains a 

 mangled specimen, apparently a M3^sidopsis, and probably referable to this 

 species. The total length is about 7 mm. The cephalo-thoracic shield is 

 displaced ; the trunk is much macerated ; the legs have disappeared, except the 



