460 



INDEX. 



Siphonodentalium, new British sjje- 



cies of, 250. 

 Siren pisciformis, on the regeneration 



of thehrabs in, 149, 446. 

 Skeleton, on the theory of the, 141, 



388. 

 Somphoxylon, observations on the 



genus, 262. 

 Soridia, new species of, 49. 

 Spencer, H., on the theory of the 



skeleton, 388. 

 Sphseroflorum, observations on the 



genus, with description of a new 



species of, 1 . 

 Spiders, new, 202. 



Spirifer cuspidatus, on the shell- 

 structure of, 68. 

 Spirospermum, observations on the 



genus, 14. 

 Squirrels, synopsis of the, in the 



British Museum, 270, 323, 415. 

 Steindachner, F., on new fishes, 79. 

 Sticharium, description of the new 



genus, 63. 

 Svnclisia, observations on the genus, 



'170. 



Syrrheonema, observations on the 

 genus, 19. 



Tadunus, characters of the new ge- 

 nus, 34. 



Taeniolabrus, description of the ge- 

 nus, 79. 



Tamias, synopsis of the species of, 

 434. 



Taygetes, new species of, 216. 



Terebratella Spitzbergensis, on the 

 occurrence of, at Unst, 248. 



Terinos, new species of, 3.99. 



Thanasimodes, description of the 

 new genus, 319. 



Theridiou, on some species of, new 

 to Britain, 210. 



Thysanura, on the, 361. 



Tribonyx, on the species of the ge- 

 nus, 122. 



Trichopterous pupae, a way to deter- 

 mine, 384. 



Trivia, new species of, 215, 436. 



Trochus niloticus and T. maximus, 

 on the different ages of, 97. 



Tympanocryptis, new species of, 52. 



Typhloplana, new s])ecies of, 300. 



Upeneus, new species of, 59. 



Ursus lasiotus, note on, 301. 



Utriculariffi, on the aeriferous vesicles 

 of the, 389. 



Utriculus, new British species of, 

 252. 



Vei;rill, A. E., on some remarkable 

 instances of Crustacean parasitism, 

 230 ; on the external characters of 

 Elasmognathus Bairdii, 232. 



Verrucaria, on the species of, found 

 in Lombardy, 1 06 ; new British 

 species of, 256, 259. 



Victoria, on the recent zoology and 

 paleontology of, 175. 



Vorticellae, on the j^henoniena of 

 muscular contraction in the, 145. 



Waldheimia venosa, observations on, 

 81. 



Walker, J. F., on a phosphatic depo- 

 sit at Potton, in Bedfordshire, 118. 



Wreden, R., on two new forms of 

 plants parasitic on man, 385. 



Xenocharax, description of the new 

 genus, 114. 



Zoological nomenclature, on the laws 

 of, 233. 



END OF THE TWENTIETH VOLUME. 



PRINTED BY TAYLOR AND FRANCIS, 

 RED LION COURT, FLEKT STREET. 



