Crustacea from Scifltis/i Waterg. 3!} 



"50 n.ilcfl N. hy W. of ICa-I.' Island, Co. Mayo." Ono 

 fi'malf rjO mm. was obtained at 7UU I'atliom.s *. Uev. T. K. It. 

 Stchbiiig ri'tnark.s tliat Cyatosoma has spociea which comljiiie 

 a length of 4 or 5 inches with the respectable breadth and 

 <h>|)th of an incli in the amplest part of tho head f- The 

 specimen from the Faroc-Slietland Channel, judged by 

 dimensions like these, must be rc'rardud as " small." 



( ' P E r U A - C A L A N I I) A. 



Genus Pseudotmarvbis, T. Scott. 



Pbeudothtiryl'ls duhiiui, sp. Ji. ( ? ). 

 (PI." I II. tigs. 1-15.) 



Body moderately stout, forehead rounded, rostrum small, 

 last thoracic segment scarcely produced and rounded at the 

 sides, abdomen and caudal rami short. 



Antennnle on the (?) left % side composed of twenty-four 

 joints, the first two stout, other joints small, but the eiirhth 

 and the penultimate joints are rather longer tiian the others. 

 The (?) right antennulc is composed of eighteen joints, but is 

 otherwise somewhat similar to the left; both are provided 

 with several short sensory filaments (tigs. 2 & 3). 



Antennae with the inner ramus considerably shorter than 

 the outer, as in Tli(iry}>is, G. O. Sars. 



Mandibles with tlie masticatory end truncated and armed 

 with strong teeth, and the palp is moderately large and two- 

 branched. Maxilla nearly as in IViarybis. 



First maxillipeds small, but armed with two moderately 

 strong spiniform setse and a number of stout bristles (tig. 8). 

 iSecond maxillipeds somewhat similar to those of T/iarylns, 

 but the first basal joint is furnished with stout, curved^ spini- 

 form setie on the inner distal angle in addition to several 

 bristles (fig. U). 



In the first pair of swimming-feet the spines on the outer 

 distal angles of- the first and second joints of the outer 

 branches are long and slender. The exterior marginal spines 

 on the outer branches of the other threci pairs are also mode- 

 rately elongated, while the terminal spines are neiirly one and 



• " iVlajric Amphiptxlft of the Irish Atlantic Slope," Fisheries, Ireland 

 Sci. Invest. 190.5, iv. (15.HX)) p. 17. 



t ' A Historj' of C'rustftcca,' p. 30. 



I The antennules were dissected ofi" and mounted ore the diflPfrence 

 between them was observed, and there ia some doubt as to which is right 

 aod which is left. 



3* 



