REPORT ON THE OSTRACODA. 73 



of 7 fathoms in Hong Kong Harbour. It is a widely-distributed species ; shells not speci- 

 fically separable from it having been met with in the British seas, in those of Norway, 

 and in the Mediterranean (?). As a Post-Tertiary fossil it has Ijeen found in Scotland, 

 Ireland, and Norway. The specimens from these various localities differ, doubtless, in 

 minor details both of fonii and surface sculpture, but not so much as to preclude grouping 

 them under one specific name. The two following species, Cythere cancellata and Cythere 

 canaliculata, approach it very closely, but the former may be distinguished by its ovate 

 dorsal and more rounded or reniform lateral outline, the latter by the more flexuous 

 lateral outline, broad dorsal surface, and regular disposition of the very large central ex- 

 cavations of the shell. 



[PI. XIV. fig. 8, a-d. a Shell seen from left side, h from above, c from below, d from 

 front. Magnified 60 diameters.] 



20. Cythere cancellata, G. S. Brady (PI. XIV. fig 9, a~e). 



Cythere cancellata, Brady, Les Fonds de la Mer, torn. i. (1868), p. 62, pi. vii. figs. 9-11. 



Shell oblong, rather tumid ; seen from the side, subreniform, scarcely higher in front 

 than behind, height equal to about half the length ; anterior extremity obliquely rounded, 

 and divided below the middle into several short blunt teeth ; posterior also well rounded, 

 and sometimes delicately toothed below the middle ; dorsal margin very gently arched 

 and slightly sinuous, ventral nearly straight ; seen from above, ovate, with obtusely 

 pointed and nearly equal extremities ; sides somewhat sinuous, width equal to half the 

 length ; end view irregular, boldly arched above, sides converging downwards towards a 

 narrowed ventral line. Surface of the shell marked (as in Cythere crispata) with closely- 

 set angular excavations, and, in old specimens (figures d, e), with sinuous, obliquely trans- 

 verse ribs. Length, l-35th of an inch ('75 mm.). 



Dredged off Mukuolofa, Tongatabu, 18 fathoms, coral (Station 172) ; and off Booby 

 Island, 6 to 8 fathoms (Station 187). The type specimens were from Java. 



[PI. XIV. figs. 9, a-e. a Shell seen from left side, b from above, c from front, d right 

 valve of adult seen laterally, e the same from above. Magnified 50 diameters.] 



21. Cythere canaliculata (Keuss), (PI. XIV. fig. 7 a-d). 



Cypridina canaliculata, Eeuss, Haidinger's Abhand. (1850), Bd. iii. p. 76, tab. ix. fig. 12. 

 Cythere canaliculata, Egger (1858), Ostrak. der Miocan.-Schicht., Bd. v. p. 33, t. v. figs. 



10, 11. 

 C]jtherz canaliculata, Brady, Trans. Zool. Soc. (1865), vol. v. p. 373, pi. lix. fig. 4, a-f. 



Carapace oblong, rather tumid ; seen from the side, subsigmoid, highest in the middle, 

 the height being equal to at least half the length ; anterior extremity well rounded, 

 posterior oblique, rounded off with a fuU curve below, and forming a distinct angle mth 



(zOOL. CHALL. EXP. — PART III. 1880.) C 10 



