90 



extremity, beaks, and dorsal edge of a purplish tint possessing a 

 somewhat metallic lustre ; the interior is of a light purple tint and 

 somewhat shining lustre ; the ribs are numerous, about 34 in nuni- 

 ber, and prominent, and the surface between them is striated longi- 

 tudinally and impressly punctate, the striae extending across one-half 

 the space, ths other half being occupied with the punctations. 

 Hab. India, Capt. Boys. Brit. Mus. 



Sp. 8. EsTHERiA siMiLis, Nobis. (PI. XI. f. 7, 7a, 7b, 7c.) 

 Carapace-valves elongate obovate ; anterior extremity considerably 

 broader than posterior, which is rather narrow ; beaks very promi- 

 nent, placed very near anterior extremity ; carapace opake ; colour 

 externally and internally the same as in last ; the ribs are numerous 

 and prominent, the first 7 or 8 rather broader than the rest, smooth, 

 and flattish ; the remainder sharply prominent, and having on their 

 surface a row of sharp angular beads ; the surface between the ribs 

 is deeply striated, the striae extending nearly quite across the space. 

 This species differs from the preceding in being smaller, more elon- 

 gate in proportion ; in having the posterior extremity considerably 

 narrower and sharper, and the beaks nearer anterior extremity, and 

 in having the ribs beaded. 



Hab. India, Capt. Boys. Brit. Mus. 



Sp. 9. EsTHERIA TETRACERA. 



Syn. Limnadia tetracera, Krynicki, Bull. Soc. Imp. Nat. Mos- 

 cou, 1830, 176. t. 7. f. 1, 2. M. Edwards, Hist. Nat. Crust, iii. 

 363. No. 3. 



Isaura tetracera, Joly, Ann. Sc. Nat. 2nd ser. xviii. 



Carapace-valves broadly obovate ; anterior extremity broader than 

 posterior, which is obtusely rounded ; beaks prominent, very near 

 anterior extremity. 



Not having seen this species I cannot describe the structure of the 

 carapace. 



Krynicki describes this species as a Limnadia, but at the same 

 time remarks "that it ought to form the type of a new genus." 



Hab. Neighbourhood of Charkow, Russia, Krynicki. 



June 12, 1849. 

 W. Spence, Esq., F.R.S., in the Chair. 



The Secretary reported that the youngest female Bison had given 

 birth to a calf in the Menagerie on the 6th inst. after an apparent 

 gestation of 270 days. A fine male example of Macropus major had 

 been added to the collection by purchase. 



