The work of these years may be roughly divided into a period of geology from 1842 to 1846, and one of zoology from 1846 onwards.
I extract from his diary notices of the time spent on his geological books and on his 'Journal.'
'Volcanic Islands.' Summer of 1842 to January, 1844.
'Geology of South America.' July, 1844, to April, 1845.
Second Edition of 'The Journal,' October, 1845, to October, 1846.
The time between October, 1846, and October, 1854, was practically given up to working at the Cirripedia (Barnacles); the results were published in two volumes by the Ray Society in 1851 and 1854. His volumes on the Fossil Cirripedes were published by the Palaeontographical Society in 1851 and 1854.
Some account of these volumes will be given later.
The minor works may be placed together, independently of subject matter.
"Observations on the Structure, etc., of the genus Sagitta," Ann. Nat. Hist. xiii., 1844, pages 1-6.
"Brief descriptions of several Terrestrial Planariae, etc.," Ann. Nat. Hist. xiv., 1844, pages 241-251.