204 NATURAL HISTORY. 



work Forbes described and figured all the recognised species 

 of the smaller British jelly-fishes, which are called ' naked- 

 eyed/ because the little coloured eye-spots are placed con- 

 spicuously round the margin of the swimming-bell. 



With regard to the star-fishes, sea-urchins, and other 

 Echinoderms, Forbes wrote a number of valuable works, 

 to say nothing of detached memoirs in different scientific 

 periodicals. The chief of these are : 



1 i ) 'A History of British Star-fishes and other Animals 

 of the class Echinodermata.' This familiar work was 

 published by Van Voorst in 1841 as one of his series of 

 treatises on British zoology. It not only contains illustra- 

 tions of all the species described, but is embellished with 

 the picturesque or fanciful tailpieces which Forbes loved 

 to design. 



(2) A ' Monograph of the British Fossil Asteriadae,' 

 published in the memoirs of the Geological Survey in 

 1848. 



(3) A 'Monograph of the Silurian Cystideae of Britain,' 

 also published in the memoirs of the Geological Survey, in 

 the same volume as the preceding. 



(4) 'Figures and Descriptions of British Organic 

 Remains : Echinoderms.' This constituted the third 

 'decade' of a series of palaeontological publications 

 issued by the Geological Survey ; the title of ' decades ' 

 being given to them because each number was supposed 

 to contain ten plates. 



( 5 ) ' A Monograph of the British Tertiary Echino- 

 derms,' published by the Palaeontographical Society in 

 1852. 



Thirdly, in the department of the Shellfish (Mollusca], 



