456 
INDEX to VOL. XX. 
Ausstss, new species of, 113. 
Ambassis, new species of, 57. 
Amblyopus, new species of, 79. 
Amphidecta, description of the new 
genus, 404. 
Amphioxus, on the anatomy and 
physiology of, 302. 
Animal mechanics, on some elemen- 
tary principles in, 294. 
Annelida, on the structure of the, 337. 
Antitaxis, observations on the genus, 
12. 
<> 
it 
Apate, observations on the genus, . 
with descriptions 
83. 
Aphis of the maple, on the develop- 
ment of the, 149. 
Apocryptes, new species of, 117. 
Apogon, new species of, 58. 
Argonauta, on the species of, 103. 
Aristega, observations on the genus, 
173. 
of new species, 
Arthonia, new British species of, 256. 
Aspergillus, on two new. parasitic 
forms of, 385. 
Assiminea Francesiz, note on, 77. 
Asterosmilia, observations on the ge- 
nus, 127. 
Ateles, new species of, 300. 
Atherina, new species of, 64. 
Athyris, on the classification of the 
subdivisions of M‘Coy’s genus, 233. 
Augyles, characters of the new ge- 
nus, 41. 
Axolotl, on the regeneration of the 
limbs in the, 149, 446. 
Balenoptera rostrata, on the anatomy 
of, 299, 
Balanoglossus, on the anatomy of, 
230. 
Balbiani, M., on the development of 
the brown Aphis of the maple, 149. 
Bargus, characters of the new genus, 
34, 
Battersbyia, observations on the ge- 
nus, 127. 
Bert, P., on the anatomy and phy-— 
siology of Amphioxus, 302. 
Billings, E., on the classification of 
the subdivisions of M‘Coy’s genus 
Athyris, 233. 
Birds, new, 269. 
Blackwall, J., on new species of Spi- 
ders, 202. 
Bledius, observations on the genus,30, 
Bocage, J. V. Barboza du, on Hyalo- 
nema lusitanicum, 123; on two 
new Saurians, 225. 
Books, new :—Clarke’s List of Flow- 
ering Plants, Ferns, &c., collected 
in the neighbourhood of Andover, 
73; Key’s Flora of Devon and 
Cornwall, 7b.; Jenyns’s Bath Flora, 
76.; Trimmer’s Flora of Norfolk, 
ib.; Gwyn Jeffreys’s British Con- 
chology, Vol. IV., 378; James- 
Clark’s Mind in Nature, 381; 
Hamlet Clark’s Letters Home,443. _ 
Bostrichus, new species of, 88. 
Butler, A.G., on some new genera 
and species of diurnal Lepidoptera, 
216; on a new species of Tiger- 
moth, 218; on the Lepidopterous 
insects hitherto included in the ge- 
nus Pronophila, 266; on new or 
little-known Asiatic Lepidoptera, 
399; on a new genus of American 
Satyridee, 404. 
Cadulus, new British species of, 251. 
Callerebia, description of the new ge- 
nus, 217. 
Campodee, observations on the, 361. 
Carpenter, Dr. W. B., on the shell- 
structure of Spirifer cuspidatus, 68; 
on the structure and affinities of 
Eozoon Canadense, 134. 
Carte, Dr. A., on the anatomy of 
Baleenoptera rostrata, 299. 
Cervus megaceros, notes on, 77, 152, 
301. 
Charaxes, new species of, 400. 
Cheilopoma, description of the new 
genus, 20. 
Chiroleptes, new species of, 54. 
Claparéde, E., on the structure of the 
Annelide, 337. 
Clarias, new species of, 111. 
Clerome, new species of, 401. 
