Mr. G. S. Brady on Marine Ostracoda firom Tenedos. 221 



two common northern species, P. trigonella and P. mytiloides^ 

 but cannot, I think, be properly referred to either of them. 



Bairdia formosaj no v. sp. (Plate XIV. figs. 5-7.) 



Carapace, as seen from the side, subtriangular, highest in the 

 middle; height equal to considerably more than half the 

 length : anterior extremity rounded and bordered below the 

 middle with several (usually from six to ten) unequal short 

 spines ; posterior produced below the middle into a short 

 sharp beak, below which it bears a variable number of 

 slender curved spines : superior margin very boldly arched, 

 inferior almost straight. Seen from above, subrhomboidal, 

 widest in the middle, more acutely pointed behind than in 

 front ; width equal to half the length. Surface of the shell 

 closely and regularly impressed with small rounded punc- 

 tures ; colour white. Left valve much larger than the right, 

 and overlapping on the dorsum. Length ^V inch. 



Cythere crisjpata^ nov. sp. (Plate XIV. figs. 14, 15.) 



Carapace, as seen from the side, compressed, oblong, sub- 

 reniform ; greatest height near the middle, and equal to 

 rather more than half the length : anterior extremity ob- 

 scurely rounded and crenulated below the middle, posterior 

 truncate : superior margin gently arched, slightly excavated 

 in front of the eyes ; inferior almost straight : all the mar- 

 gins more or less rugged. Outline, as seen from above, 

 oblong, subquadrangular, widest behind the middle, broadly 

 mucronate in front, truncate behind, deeply constricted at 

 the anterior third, and more gently near the middle ; width 

 considerably less than half the height. Surface of the valves 

 exceedingly irregular, marked with waved, rounded, and 

 irregularly flexuous ridges. Colour yellowish brown. 

 Length ^^ inch. 



This so much resembles, in outline and in style of surface- 

 marking, Cythere hadia^ Norman, that in my ' Monograph of 

 the Recent British Ostracoda,' I have, in the note on distribu- 

 tion, referred it to that species. A reexamination of the spe- 

 cimens, however, has induced me to believe that it ought to be 

 considered distinct, though it must be admitted that the dif- 

 ferences are chiefly of degree rather than of kind, consisting in 

 the larger size and the excessive development of the rugosities 

 of the surface. There is, however, a good distinctive character 

 in the truncate posterior extremity. It seems to constitute a 

 link between G. hadia and a form previously (Trans. Zool. 

 Soc. vol. V.) referred by me to Cythere canaliculata^ Reuss. 



Ann. & Mag. N. Hist. Ser. 4. Vol. ii. 16 



