258 Rev. Canon A. M. Norman on British Mysidse. 



about three times as long as broad and one third longer than 

 peduncles of antennules, about one third of its length ex- 

 tended beyond the spine which terminates the naked outer 

 margin. Legs having the tarsus subequal in length to the 

 preceding joint, composed of four articulations, the first of 

 which is very sliort and nodulously swollen ; nail long and 

 slender ; last perseopods very short, about half the length 

 of preceding pairs, and without any nail. Telson broad, sides 

 flexuous, but the breadth much more equal throughout the 

 length than usual, scarcely narrowing distally ; greatest 

 breadth subequal to half the length ; cleft short, scarcely one 

 fifth of length, triangular, widely open ; lateral margins of 

 telson with 14-16 spines distributed throughout the length. 

 Inner uropods a little longer than telson, with only about 

 nine widely separated spines on the inner margin, the most 

 distal some way from the extremity. Outer uropods nearly 

 one third longer than the inner. Length 11 millim. 



Hab. Guernsey; Starcross, Devon {A, M. N.) ; Jersey 

 [Sinel) : Mus. Nor. 



Distribution. In the Mediterranean at Goletta, Syracuse, 

 and Spezia (G. 0. Sars). 



The nodulous first joint of tarsus of the legs and tlie 

 few spines on the margin of the inner uropods distinguish 

 8. Ilelleri from the species which have a somewhat similar 

 antennal scale. 



5. Schistomysis arenosa (G. 0. Sars). 



1876. Mysis arenosa, G. O. Sars, Nye Bidrag til Kundskaben om 

 Middelhavets Invertebratfauna, I. Middelliavets Mysider, p. 16, 

 pis. V. and vi. 



1883. Austromysis arenosa, Czerniavsky, I. c. fasc. iii. p. 67. 



1885. Mysis arenosa, Cams, /. c. p. 466. 



1886. Mysis aj-enosa, Norman, Fourth Annual Report Fishery Board 

 of Scotland, p, 159 ; and Ann. & Mag. Nat. Hist. ser. 5, vol. xix. 

 1887, p. 95. 



A small species of short and very robust form, much 

 coloured with pigment-cells, especially upon the cephalo- 

 thorax ; pleon shorter than usual. Eyes very short, sub- 

 globose, scarcely reaching beyond the sides of the cephalo- 

 thorax ; cornea large. Antennules with robust peduncle. 

 Antennal scale short, subrhomboidal or subovate, scarcely 

 longer than peduncle of antennules ; length scarcely exceed- 

 ing twice the breadth ; inner margin more arched than usual, 

 outer margin also slightly arcuate ; nearly one half of the total 

 length of scale extended beyond the spine which terminates the 

 naked outer margin. Legs with tarsus shorter than preceding 



