118 ^ Descriptions of Preparations. 



A very clear account of the nerve system of the various orders of 

 Crustacea may be found in Frey and Leuckart's Lehrbuch 

 der Zootomie, 1847, pp. 195, 623. 



For an account of the development of the nervous system of the 

 Crayfish, see Rathke, Ueber die Bildung und Entwickelung 

 des Flusskrebses, 1829, pp. 32, 33. 5°^ ^i, 64, 85. For that 

 of the Scorpion, see Rathke, Morphologic Reise nach Taurien, 

 p. 28, cit. Huxley, Linn. Soc. Trans., vol. xxii., pp. 227, 



228. 

 For a figure of the nervous system in the common Lobster, Homarus 

 Vulgaris, see Newport, Phil. Trans., 1834, pi. xvii. fig. 40 > 

 where, however, the evident constriction of the first post-oral 

 ganglionic mass has caused the writer to count it as two, and 

 to speak of the entire number of ventral ganglia as being 

 thirteen. The relative superiority in size of this first post-oral 

 ganglion is not so marked relatively to those which come 

 posteriorly to it in the marine as it is in the flaviatile species 

 here contrasted. 

 For the nervous system in the Decapodous Crustacea generally, see 



Leydig, Vergleichende Anatomic, Bd. i. p. 253, ihique citata. 



For the stomato-gastric system, see Huxley, Medical Times and 



Gazette, April 11 1857, p. 353; Brandt, Ann. Sci. Nat. 



Ser. ii. tom. v, 1836, p. 87, pi. 4, figs, i, 2, 3. 



For the nervous system of Myriapoda and Macrurous Arachnida, 



see Newport, Phil. Trans., 1843, pt. ii. pp. 243-272 ; and for 



the structure of the cord, p. 248, and Phil. Trans., 1834, 



p. 406, pi. xvii. fig. 42; Leydig, Vergleich. Anat., pp. 229- 



241 ; and Helmholtz cit. in he; Carpenter, Comp. Physiology, 



p. 669. 



For various views as to the homologies of the segments, see 



Savigny, Memoires sur les Animaux sans Vertebres, 1816; 



Milne-Edwards, Histoire Naturelle des Crustaces, 1834, p. 50; 



Ann. Sci. Nat., 1851; Erichson, Entomographien, 1840; 



Lacaze Duthiers, Ann. Sci. Nat., Ser. iii. tom. xvii., 1852, 



pp. 227, 232, 233, tom. xix., pp. 34. 40. 229-233 ; Dana, 



Crustacea, U. S. Exploring Expedition, 1852, p. 19 ^e^?. ; 



Zenker, Archiv. fiir Naturgeschichte, 1854, p. 118; Van der 



Hoeven, Handbook of Zoology, English translation, vol. i., 



1856, p. 557, ihique citata; Huxley, Linn. Soc. Proc, vol. 



