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J. M. Thomson 
not operculiform and the mouth parts are of the biting type. In all of 
hich features it differs widely from Crura nthura. The general arrange- 
ment and structure ot the antennae of Cruranthura are similar to those of 
C olanthura. But the latter genus is distinguished by the following points: 
the seventh thoracic segment is narrower than those in front and narrower 
than the abdominal segments ; the abdominal segments show no sign of dorsal 
fusion ; the telson is lingiffform and appears to be without setae; no tooth 
defines the palm of the pereiopod in any described species of Colantliura. 
I nlortunately Richardson's description gives no account of the mouth parts. 
Of all the Anthurid genera Cruranthura undoubtedly comes nearest to 
(ruregens Chilton. The maxilliped structure is identical, except that some 
setae occur along its length in Cruranthura , not merely apically. It is pos- 
sible however that such is the case with C ruregens though ' neither Chilton’s 
nor Barnard s figures show this, and Chilton’s description reads “The ter- 
minal portions are free, and the ends .... are tipped with setae . ” The 
structure of pereiopods and antennae are also similar. Cruranthura differs 
lrom C ruregens in the presence of eyes, the subterranean C ruregens being 
without them. The exopods of the uropods in Cruregens do not arch over- 
the telson and they are long narrow filaments, whereas in Cruranthura 
they are shorter, broader and lamelliform. Also Cruregens shows no signs 
