Report on the Crustacea Sehizopoda of Ireland. 241 
The relations of the antennal scale to the peduncle of the antennule give 
results as follows:—A. antennal 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; G. 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 I. flexuosa and M. neglecta. 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 J. flexuosa; in A the shape is intermediate; in B and K the scale is 
imperfect ; in the remaining specimens the shape approaches M/. 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) :— 
1 1 1 
A. Cll. &. ““ neglecta”? ; Pe. ‘ neglecta” ; K. & ‘ flexuosa” 5 
1 : ; 
B. Cd. 5. “neglecta” ; H. intermediate ; Ib, = ‘* flexuosa”? ; 
Theres sik 1 1 
C & to 6 “* neglecta” ; I. & Me 55 
1 B fl 1 
BE & “« flexuosa” ; Te i(@)3 Ne Ct. 5. ‘¢ flexuosa.” 
The lateral spines of the telson are :— 
20 p21; H. 22; K. 22; 20 
~° Fi! 23 24 20 aT 
F, -~=3 I. 3 L. ——} 
mR, Babe 23 24 Hil 
Pall 20 20 
Gh Bee G. 553 J. oy} M. 53 3 
The preceding details may be summed up in a table showing to which species 
the individuals incline in the characters of different parts. 
