ADDENDA ET CORRIGENDA. 138 



almost all Cretaceous Asteroids, and in quite young forms of the order " Crypto- 

 zonia," tlie margin of the disc and arms is bordered by specially prominent plates 

 the " Marginalia." The abactinal series are called " Supero-marginalia," and the 

 actinal series the " Infero-marginalia." 



Primary Inter-radialia. See Central?. 



Ltadiid'ut. The abactinal series of plates along a major radius are called the 

 radialia. 



-A line drawn from the central point of the disc to an extremity of 

 the arm is called the " Major radius," R. A line drawn from the central point of 

 the disc to a point half-way between two radii is called the " Minor radius," r. 

 This is sometimes called an " Inter-radius." 



Spine-pits. Depressions in a plate for the articulation of spines (see p. 113). 



V/'iitro-latumlia. The plates on the actinal surface of the Asteroid excluding 

 the infero-marginalia and the adambulacralia. In the inter-radial regions these 

 plates are often rhomboidal. A typical view of an isolated plate of this descrip- 

 tion is given (PL XXIX, fig. 4). 



ADDENDA ET CORRIGENDA. 



Page 24, line 19, for Schiilze read G. F. Schulze. 



Page 26, Locality, etc., for Upper White Chalk near Norwich read Hard Chalk, 

 West Norfolk, the precise locality unknown. 



Page 67, line 11, for Goniaster compactuts read Goniaster (Goniodiscus) compactus, 

 and omit all reference to Forbes, 1848. 



Page 69, line 15, for Stcllaster comptoni read Goiiiaxter (Stellaster) Comptoni. 



Page 71, line 4, for Stellaster elegans read Goniaster (Stellaster) elegans. 



Page 89, line 8 from end, for Bourguetiocrinus read Bourgueticrinus. 



Page 90, last line, for Upper Greensand read Lower Chalk. 



Page 95, line 3, for Sladen read Forbes. 



Page 95, line 13, for (p. 89) read (p. 89, PL XXV, fig. 7). 



Page 101, line 9 from end, the first reference should read OPHIURA, Lamarck, 

 1801. Systeme des Animaux sans Vertebres, p. 350. The date of the reference 

 given is 1816. 



Page 102, line 12, for 1841 read 1840. 



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