,-, , ME. G. S. BRADY'S MONOGRAPH OF 



,,,,„ ,1,, ,hr. ■ follouing; penultimate joint of the lower antenna, very slender, and 



twi „. as long as the preceding. Branchial appendage of the mandible tatting eight 



,,,,„,!,„ nting seL Seeond joint of the last pair of feet shorter than the two 



roll.iuin " 





Lenirth . , ., in. 



1:1 



//„/,. liure; i., depths of 10-60 fathoms. 



Nortl 



Minch, and one dead shell in rock-pool, Herm (Rev. A. M. Norman) 



Genus 12. Cytherideis, Jones 





Carapace slender, elongate, subovate, tapering towards the front, not mueh compressed 



1 1 inn-e-margins nearly simple ; shell smooth, finely punctate. The right valve 



•allv 



, flapping the left in the centre of the ventral aspect. Animal unknown 

 Cytii i kideis subulata, Brady. (Plate XXXV. figs. 43-46.) 



there fin Ida, Baird, Brit. Eatom. p. 168, t. xxi. figs. 12, 12 a. 



B -h type. Distribution: 2te«*/-Britain, Ireland, Bay of Biscay, Cape Verd, Levant. Fossils 



(ilacial, Scotland. 



Carap 



Seen 



mwf j from the side, much attenuated in front, highest behind ; greatest 



^ ua l to one-third of the length ; sharply rounded in front, broadly and obliquely 



numdrd behind. Superior margin sloping with a gentle curve from the middle forwards 

 Dearly straight behind the middle ; inferior margin gently sinuated in the middle. 

 from above, the outline is compressed ovate, widest behind, tapering to an acute point 

 at each extremity ; greatest width equal to one-third of the length. Shell thin and fragile, 

 Uowish, marked with fine closely set impressed puncta ; the anterior and posterior 

 margins with transverse radiating lines ; centre of the valves obscurely sulcate trans- 



ly. End view circular. Animal unknown 



Length 



Mumbles, Donegal Bav, and Roundstone (G. S. B.) ; Macduff 



Jeffreys) 



M. Norman) 



All the examples of this species which I have seen are merely empty shells, and 

 t herefore I cannot refer it with certainty to its proper position. The shell, though in its 

 lateral aspect very similar to some forms of Paradoxostoma, differs in some important 

 particulars : it is not laterally compressed as all the elongated forms of the latter genus 

 ire ; the shell is more horny in character, and not smooth and polished. The lucid spo 

 arc four, large, quadrangular, and irregularly grouped. Lastly, the overlapping ventr 

 margin of the right valve almost certainly proclaims that it cannot belong to that genus, 

 which always exhibits a longitudinal aperture between the two contact-margins in iron , 

 for the protrusion of the suctorial apparatus. Under these circumstances, I nav 

 retained for this species the generic term Cytherideis, under which group, as original y 

 defined by Professor Rupert Jones, it would naturally fall. Muller's Cy there flavidcu 

 with which Dr. Baird identifies it, seems to me to belong to another species, probably 



Peradoxostoma tariubile. 



