364- Messrs. J. Wood-^Iason and A. Alcock on 



Til our younp^est specimen it is sliort aiul porrect, scarcely 

 extending beyond tlie second third of the length of the 

 antennal scale, and being niucli shorter than the carapace. 

 In a somewhat older specimen it is decidedly ascendant, 

 though still straight, and longer — reaching to the apex of the 

 antennal scale — though still much shorter than the carapace. 

 Jn a still older specimen it has almost completely attained 

 the length and the upward curvature it has in adolescent 

 specimens, though it is still distinctly shorter than the cara- 

 ]iace. It is as long or longer than the carapace in all our 

 adolescent specimens of both sexes, except the two largest, 

 and in these, which are males, it is slightly shorter than the 

 carapace ; wlience it may with some confidence be inferred 

 that, as in A. escimia^ A. Ar/assizii, S. I. Smith, and A. an- 

 ffusta, Spence Bate, it does not surpass the antennal scale in 

 fully developed males. It is from ^ — toothed. 



In all our specimens the eye is much as in Spence Bate's 

 figure of ^. avgusta, not as in his fig. 7, pi. cxxvi., in which 

 the so-called ocellus is represented as round and separate 

 from the rest of the eye. 



It appears to us probable that A. ongusta is the adult male 

 oi A. brachytelsonis, the difference between the two in the 

 number of the rostral spines being explained by the loss of 

 the apical s])ine of the lower series in the process of reduction 

 of the rostrum from the adolescent to the adult condition in 

 the former; and possible that A. hrachytelsonis itself will 

 prove to be identical with A. exi'mia, since the former differs 

 from the latter only in having one spine less on the inferior 

 margin of the rostrum, and since Spence Bate includes 

 amongst the specimens referred by him to the former indivi- 

 duals with the same number of spines as in the latter. 



42. Acanthephyra curtiro^tn's^ V\ .-^{. 



Acanthephym curiirostris, Wood-Mason, Ann. >.^- Mag. Nat. lli?t. (<!) 

 vii. p. I'Jo, (S- 



? . Dilfers from the male only in its slightly more pro- 

 duced rostrum. 



cJ ? . The rostrum is '-^-toothed. 



(J. The telson bears 9-10 pairs of dorsal spinuk-s and 5 

 somewhat longer apical ones, the median of whicii is appa- 

 rently fi.Kcd. 



