6622 



Crustacea. 



by Mr. M'Gillivray in one of the islands of the Eastern Archipelago, and now in the 

 British Museum collection. 



Mr. Shepherd thought, with Mr. Westwood, that Mr. Wallace's description agreed 

 with O. Tithonus, but considered it hardly possible that Mr. Wallace was not 

 acquainted with De Haan's figure. Previous to leaving this country for the East, 

 Mr. Wallace had carefully investigated the works containing descriptions and figures 

 of the entomological productions of the countries he was about to visit ; and it seemed 

 almost incredible that he could have overlooked or forgotten this fine insect. 



Mr. Baly read a paper on new species of Phytophagous insects, together with the 

 characters of a new genus, Paralina : this latter is closely allied to Lina and Chryso-- 

 mela, and is separated from these genera on account of its produced meta-sternum, 

 which, passing forwards between the meso-coxae, articulates with the base of the pro- 

 sternum, entirely concealing the meso-sternum ; its type is Lina Indica, Hope. — 

 E. S. 



The Crab and its Allies. 

 By C. Spence Bate, Esq., F.L.S., &c. 



(Continued from p. 6578.) 



It will be here, perhaps, desirable rapidly to review the nervous 

 system of the Crustacea. 



The symbolical Crustacean consists of twenty-one segments, every 

 one of which carries a pair of limbs. The nervous system that 

 supplies these segments and their appendages consists of a series 

 of ganglia, one being lodged in each successive segment, and 

 connected to each other by two parallel nervous cords : the whole of 

 these lie close to the ventral surface of the integument and beneath 

 the organs of the body, except the three anterior pair, which supply 

 organs of sense ; these are situated above, or, rather, I should say 

 before, for the oral aperture is situated in the fourth segment ; they 

 give off threads to the members and other organs : the more 

 important parts are supplied from the ganglia ; those of less conse- 

 quence receive their supply from the intermediate cord. Though 

 this is the type of the nervous system, yet in no known Crustacea is 

 it found exactly to correspond. In all there is a tendency of the 

 ganglia and the corresponding segments to fuse with each other; this 

 is of a degree more or less in different species or groups ; thus, in the 

 sessile-eyed Crustacea all the ganglia are distinct except the seven 

 anterior ; the three first form one, the supra-cesophagal ganglion, as it 

 is named ; the four succeeding build up the infra-cesophagal, which 

 are so called from their relative position to the alimentary tube. But 



