IX 



ZOOLOGICAL NOTES AND OBSERVATIONS MADE ON 



BOARD H.M.S. RATTLESNAKE DURING THE 



YEARS 1846-50 



Annals and Magazine of Natural History, vol. vii. ser. ii. 1851, //. 304-6/ 

 370-4/ vol. via. pp. 433-42 



I. On the Auditory Organs in the Crustacea. 



Great discrepancy prevails among the various authorities as to 

 the true nature and position of the auditory organs in the Crustacea. 



The older authors, Fabricius, Scarpa, Brandt, Treviranus, unani- 

 mously confer the title of auditory organs upon certain sacs filled 

 with fluid which are seated in the basal joint of the second or larger 

 pair of antennse. 



M. Milne-Edwards, in his elaborate researches upon the Crustacea,^ 

 adheres to this determination, and describes a very elaborate tympanic 

 apparatus in the Brachyurous genus Maia. 



By the majority of the earlier writers no notice is taken of the sac 

 existing in many genera in the bases of the first or smaller pair bf 

 antennae. Rosenthal'^ however describes this structure very carefully 

 in Astacus fluviatilis and Astacus marinus. He considers it to be an 

 olfactory organ, while he agrees with previous writers in considering 

 the sac in the outer antennse as the auditory organ. 



Dr. Farre, in his admirable paper in the Philosophical Trans- 

 actions for 1843, gives very good reasons for exactly reversing 

 Rosenthal's denominations, and considering the sac in the first pair of 

 antenna; to be the auditory organ, while the sac in the second pair is 

 the olfactory organ. Dr. Farre doubts the existence of true auditory 

 organs in the Brachyura. 



Siebold in his Report upon the progress of the Anatomy of the 



^ Hist. Nat. des Crustaces. Suites a Buffon. 



^ Ueber die Geruchsorganen d. Insekten. Reil's Archiv, B. 2^. 181 1. 



