226 Prof. T. Thorell on some 



Fig. 6. E 5619, B. M. A ventral sac, slightly weathered. From a 



dra-wing by Mr. Ilollick. (X 2 diam.) 

 Fig. 7. /5742], 11 M. A small portion of the weathered surface of a 



radial. From a drawing by Mr. Ilollick. (x 10 diam.) 

 Fig. 8. E 6002, 13. M. A plate frcjm the pro.xiaial region of the ventral 



sac, to show the folding of the edges. Drawn on stone by the 



author. (X 3 diam.) 

 Fig. 9, Grindrod Collection, Oxford. The distal end of the ventral sac 



appearing between the branches of the anterior arm. Drawn on 



stone by the author. (Nat. size.) 

 Fig. 10 a. 67142^ B. M. Three brachials seen from the side, showing the 



covering-plates open. 



b. 57142, B. M. The ventral surface of three brachials, the 

 covering-plates removed and the ventral groove exposed. 



c. Grindrod Collection. The ventral surface of three brachials, 

 the covering-plates m situ and closed. 



All from drawings by the author, (x 3 diam.) 

 Fig. 11. 57060 and E 6002, B. M. A radial showing the articular facet, 



combined from the evidence of these two specimens. From a 



drawing by the author. ( X 3 diam.) 

 Fig. 12. E 6003, B. M. Portion of surfac ' oi a radial, .showing shagreen 



ornament. From a drawing by Mr. IloUirk. ( x 10 diam.) 

 Fig. 13. The articular surface of a stem-ossicle from the evidence of 



numerous .specimens. From a drawing by the author. ( x 3 



diam.) 



Cyathocrinus vallatus, sp. n. 



170, Mason Cullege. A radial seen obliquely from above, to show 

 articular facet ; also showing ornament. From a drawing by 

 Mr. Ilollick. (X 2 diam.) 



E 6006, B. M. A cup seen from the right side, showing post.B 

 and X on the left ; outline restored. From drawings by Mr. 

 Ilollick and the author. (Nat. size.) 



170, Mason College. A cup; orientation uncertain. From a 

 drawing by Mr. Ilollick. (Nat. size.) 



The articular facet for the stem of the same specimen. From a 

 drawing by Mr. Ilollick. 



E 6005, B. M. A much weathered cup ; orientation uncertain. 

 From drawings by Mr. Ilollick and the author. (Nat. size.) 



XXXIII. — On some Spiders from the Andnman Islands 

 collected hy E. W. Oates, Esq. By Prof. T. TuOHELL. 



Our knowledge of tlie araclinological fauna of the Andaman 

 Islands is as yet exceedingly limiteil; s>o far as I know M. 

 Eugene Simon is the only author wiio has, in a rocentlv- 

 published paper *, onnnieratod antl described any .-spiders 



* " Ktudes sur los Arachn. de lAsie nn^rid. faisant } artie des collec- 

 tions de rindian Musruni (Calcutta).— II. Arachn. recurillis nux ilea 

 Andaman par M. K. D. (.)ldliani," in Jouru. of tlie .\siatic ."^oc. ot^ IVn-'-jtl, 

 Ivii. part ii. no. 3 (^18i<7). 



