in the West of Ireland. 367 



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

 fore to figure and describe the species afresh*. 



The differences between C. porcellanea and C. Macallana^ 

 though small, are sufficient to require tlie 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. Botli species are very nearly allied to 

 C 2)ellucida and C. castanea, figures of Avhich 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 (C. pelluckla and castanea) ^ 

 especially the latter, have tlie valves almost always marked 

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

 males of C. porcellanea and C. MacaUana bear similar impres- 

 sions, the females are entirely free from them. 



Cythere MacaUana^ nov. sp. PL XIX. figs. 5-9. 



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

 greatest height situated in front of the middle, and equal 

 to lialf 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. Sm-face of the shell vaguely and distantly punc- 

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

 ous grooves. Colom- yellowish browni. Length J- 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 oi the female tumid ; seen from the side, subti-iangular 

 or ti-apezoidal, higliest 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 receutly had the opportunity of examinin<r a 

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

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

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



