Ueport on the Crustacea Sohizopoda of Ireland. 



241 



The relations of the antennal scale to the jieduncle of the antennule give 

 results as follows : — A. antenual scale fully double the length of the peduncle 

 of the antennule; C. distinctly more than double; D. about double ; E. barely 

 double ; F. somewhat less than double ; CI. barely double ; H. about double ; 

 I. distinctly less than double ; J. scales both perfect, but of unequal length : 

 the longer one about double the length of the peduncle of antennule ; K. 

 slightly less than double ; M. slightly less than double ; N. distinctly less 

 than double. 



The relative length and breadth of the scale can only be ascertained by 

 isolating this appendage. In the few cases in which this has been done, the 

 breadth has proved to be about one-sixth of the length. Such a proportion is 

 intermediate between the conditions of 31. Jlexuosa and M. neglccta. In shape, on 

 comparison with Sars' figures, the antennal scale appears to incline to the 

 condition of the last-named species. Specimens C and D have the apex of the 

 scale as in 31. Jlexuosa ; in A the shape is intermediate ; in B and K the scale is 

 imperfect ; in the remaining specimens the shape approaches 31. neglecta. But, 

 as far as one can judge without detaching the scale, the width is in all cases 

 intermediate. 



At what point of constriction the cleft of the telson may be held to incline to 

 one species rather than to the other is difficult to decide, but comparison with 

 Sars' figures appears to range our examples as follows (the fraction indicates 

 the length of the cleft in the total length of the telson) : — 



A. ca. -. " neglecta " ; 



B. ca. ~. " neglecta " ; 



c. c ^o ^. " neglecta''' ; 



E. -. ^^ Jlexuosa^' ; 

 6 



F. ^. " neglecta " ; 



H. intermediate ; 



1 

 '■ 6' 



'■ itG)' 



K. 7:. "Jlexuosa " ; 

 6 



L. ^- "Jlexuosa " ; 



1 



N. ca. ^. "Jlexuosa." 



The lateral spines of the telson are : — 



20 

 ^•21' 

 B. 24; 



c. 22; 



E. 21 ; 

 23 



F • 



23' 

 21 



22' 



G. 



H. 22 ; 



24 

 ^•245 



20 

 "^- 21' 



K. 22; 



20 

 ^•21' 



20 

 ''•23' 



20 

 2l" 



The preceding details may be summed up in a table showing to which species 

 the individuals incline in the characters of different parts. 



