in the West of Ireland. 367 



a correct idea of the adult shell. It has been necessary there- 

 fore to figure and describe the species afresh*. 



The differences between G. porcellanea and C. Macallana, 

 though small, are sufficient to require the separation of the two 

 species. The first-named is rather the larger, has much less 

 surface-sculpture, and, as seen from above, is more regularly 

 ovate in outline ; it is also paler in colour, and seems to be 

 sublittoral in habitat. Both species are very nearly allied to 

 G. pellucida and G. castanea, figures of which we have thought 

 it desirable to give in this place, they not having been suffi- 

 ciently discriminated in the plates illustrating Mr. Brady's 

 ' Monograph.' These species (G. pellucida and castanea), 

 especially the latter, have the valves almost always marked 

 with one, two, or more transverse furrows ; but though the 

 males of G. porcellanea and G. Macallana bear similar impres- 

 sions, the females are entirely free from them. 



Cythere Macallana, nov. sp. PI. XIX. figs. 5-9. 



Carapace of the female, seen from the side, subreniform ; 

 greatest height situated in front of the middle, and equal 

 to half the length ; anterior extremity evenly, posterior 

 obliquely rounded : superior margin well arched, highest 

 over the eyes, in front of which it is slightly excavated, 

 ending posteriorly in an obtuse angle ; inferior sinuated in 

 the middle. Seen from above, ovate, widest in the middle, 

 rounded behind, subacuminate in front ; width less than the 

 height. Surface of the shell vaguely and distantly punc- 

 tate, the ventral surface more or less marked with sinu- 

 ous grooves. Colour yellowish brown. Length -^ inch. 

 The shell of the male is longer and narrower, more tapering 

 (as seen laterally) towards the posterior extremity, and has 

 the dorsal margin almost straight ; seen from above, the 

 sides are subparallel, and the posterior extremity obtuse ; 

 the shell-surface is also usually less sparingly punctate than 

 in the female. 



Hah. Dublin, Westport, and Clifden Bays. 



Cythere gibbosa, nov. sp. PI. XXI. figs. 1-3. 



Carapace of the female tumid ; seen from the side, subtriangular 

 or trapezoidal, highest in front of the middle ; greatest height 

 equal to more than half the length, extremities obliquely 

 rounded, the anterior being much the broader : superior 



* I may add that I have recently had the opportunity of examining a 

 larger series of Ostracoda from the river Scheldt, and have found a num- 

 ber of examples of C. porcellanea differing in no respects from those de- 

 scribed in the present paper. — G. S. 13. 



