Mysidai /j*o/n the West Coafit of Ireland . 107 



Eyes well developed, normal in appearance and structure, 

 pigment liglit reddish hrown. 



Telson entire, laiieiform in shape, its margin armed with 

 more or fewer spines, median setie absent. 



Inner urojwd with a few spines on its inner margin in the 

 region of the otoeyst. 



Female with only two pairs of ineuhatory lamelhe. 



Type species, Mctauihlyops oca/at a. 



The genus L'halcojththahnus, lUig, 190G, would appear to 

 be rather closely allied to the present one, but judging from 

 Illig's tigures Metamblyops is a more compact and robust 

 form, the carapace covers all the thoracic segments, the eye 

 is much larger and its papilla quite minute, and the antenna! 

 scale com|)aratively much longer. The chief distinction lies 

 in the structure of the first thoracic limbs, which in Chalco- 

 phthahnus are described as being devoid of endopods, while 

 in Metamblyops both endopod and exopod are fully and 

 normally developed. 



Metamblyops oculata, sp. n. 



Carapace covering all the thoracic segments ; produced in 

 front into a slightly upturned, acute rostrum reaching as far 

 as, or a little beyond, the eyes, and partially covering the 

 eye-stalks ; terminal angle about G0°, its apex produced into 

 a short acute point; evenly rounded at the antero-lateral 

 corners and slightly emarginate behind. 



Pk'on longer than carapace ; the first segment one and a 

 half times as long as the second, which is subeqnal to the 

 third and fourth ; fifth segment slightly longer than the 

 fourth ; sixth segment twice as long as the fifth. 



Eyes large, well developed and normal in structure ; ex- 

 tending to the distal margin of the first joint of the anten- 

 nular peduncle ; pigmented ])ortion equal in width to the 

 last plcon-segment, a minute papilla on the inner distal part 

 of the peduncle where it joins the cornea; visual elements 

 well develo[)ed ; pigment li^ht reddish brown. 



Antenmdar peduncle about twice as long as the eye; third 

 joint a little shorter, but considerably stouter than the first 

 and more robust in the male than in the female ; second 

 joint small ; male appendage well developed and densely 

 hirsute, but otherwise of normal appearance. 



Anlennal peduncle short, not extending beyond the distal 

 end of the second joint of the antennular peduncle and com- 

 posed of three subecjual quadrangular joints. 



Anlcnnal scale about one-third as lon<r again as the anten- 



