301 



Es wäre somit für Herrn S c u d d e r eine neue Vertheidigung seiner 

 Bestimmungen nöthig, die aber nicht, wie die gegenwärtige, nur Irr- 

 thümer enthalten darf, wenn er seine Ansichten von der Wissenschaft 

 angenommen zu sehen wünscht. 



7. The Morphology of Cyclops and the Relations of the Copepoda. 



Bv Marcus M. H a r t o g , 

 D. Sc. M. A., J. L. S. Prof. Nat. Hist. Queens College, Cork. 



(Abstract.) 



eingeg. 4. April 1885. 



This paper opens with a full anatomical description of Cyclops 

 hrevicornis Claus, worked out in great part by the method of sections. 

 The chief new points made out are as follows : — In the skeleton a free 

 entosternite is demonstrated in the maxillary region, and homologised 

 with the tendon of the adductors of the valves of the bivalve Ento- 

 mostraca. A large post- maxillary apodeme in all Copepoda gives 

 attachment on either side to the great flexors of the trunk. A spring 

 arrangement is shown to relax the flexed male antennule used as a 

 clasper. Pore-canals, cells, or cutaneous glands each receive a nerve- 

 fibre at their proximal end. The hypodermal cells have a polygonal 

 outline. 



Under the mesoblastic tissue. Fries discovery of amoeboid coelo- 

 mic corpuscles is confirmed. The apparatus of deglutition is fully de- 

 scribed, and the author has made out a pair of salivary glands in the 

 epistoma whose ducts join to open on the back of the labrum by a 

 median pore. In connection with the alimentary canal, the mechanism 

 of circulation and anal respiration is described, the efficiency of the 

 latter being strongly maintained. 



The kidney or »shell gland« is shown to be a simple much-coiled 

 tube, with chitinous lining, opening at the base of the outer maxilli- 

 ped. Incidentally the presence of this organ is noted in several divi- 

 sions of the marine Copepoda, and the [author suggests that it is iden- 

 tical with the «antennary gland« of similar structure of the Nauplius 

 larva, which would have shifted its aperture. 



A full description of the nervous system follows. The presence of 

 ganglion-cells in the circumœsophageal cords is noted and used as an 

 argument for regarding the (2nd) antennae innervated therefrom as 

 oral rather than postoral appendages. 



The presence of corneal facets to the lateral ocelli is noted, and 

 an attempt is made to connect what the author has described elsewhere 

 as auditory organs with the unicellular pore-canal glands. 



