362 Messrs. Brady and Robertson on Dredfjing 



OSTRACODA. 



Lists of Species taken. 



MnUingar Canal, Dublin, 



Cypris compressa, Baird. 



reptans (Baird). 



Cypridopsis obesa, nov. sp. 

 Candona Candida (Milller). 



compressa (Koch). 



albicans, Brady. 



Limnicytbere inopiuata (Baird). 



River Liffey, at Dublin, NoHh Wall. 



Candona compressa (?) (Koch). 

 Bairdia fulva, Brady, 

 Cytbere lutea, lliiller. 



castanea, G. O. Sars. 



Cytberidea elongata, Brady. 

 Loxoconcba impressa (Baird). 



elliptica, Brady. 



Cytberuva nigrescens (Baird). 



simibs, G. O. Sars. 



cellulosa (Norman). 



cuueata, Brady. 



Paradoxostoma variabile (Baird). 



Westport Quay, in a salt-water tidal 

 pond at high-water mark, amongst 

 Zostera. 



Cytbere lutea, Milller. 

 —' — castanea, G. O. Sars. 



villosa, G. O. Sars. 



cicatricosa, G. O. Sars. 



gibbosa, nov. sp. 



Loxoconcba elliptica, Brady. 

 Xestoleberis aurantia (Baird). 

 Cytberura nigrescens (Baird). 



liobertsoni, Brady. 



Sclerochilus gracilis, nov. sp. 



Lough Moher, Mayo. 



Cypris oyiuu, Jurine. 

 Limnicytbere Sancti-Patricii, 7i. sp. 



Freshwater Loughs near Clifden. 



C>^ris Isevis, Milller. 

 Loxoconcba elliptica, Brady. 



llespecting the marine species, it should first be noted that 

 all our dredgings being made in comparatively shallow Avater, 

 many species are absent from the list which would doubtless 

 have appeared had our time admitted of dredging in greater 

 depths. Yet the results obtained are interesting, as indicating 

 some well-marked peculiarities in the fc\una of our Atlantic 

 shores. Most remarkable, perhaps, is the almost entire ab- 

 sence of Cythere luteay a species which in all other parts of the 

 British islands is one of the most abundant. Cythere tubercu- 

 lata and concinna appear also to be excessively scarce ; and the 

 strongly spinous species, such as G. antiquata and Jonesii, 

 become much less robust, with more fragile shells and fewer 

 and more attenuated spines. CytJieridea punctillnta, a spe- 

 cies veiy abundant in some of the Scottish lochs, as Avell as in 

 most glacial clays, is also absent : the same may be said of 

 Ihjohates hartonensis and Cythere dunehnensis. The common 

 Cytheropteron latissimum appears to be displaced by C. nodo- 

 sum. The occurrence of Lo.Tcoconcha ellijytica in the freshwater 

 lakes has already been noticed in our introductory remarks. 

 The species which seem to be most characteristic of the district 

 arc perhaps Cythere Macallana, 2)u1chcUay and cicatricosa^ 

 Cythcroptcroti nodosum and C. suhcircinatum. All these have 

 indeed been found on other parts of the British coast, but no- 

 where so abundantly as in those dredgings from the bays of 



