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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVIII. 



Dana; but the latter are, of course, mistaken in interpreting the gland 

 itself as nervous tissue. Furthermore, the second nerves in Caligus 

 curtus (fig. 28, 2), which Pickering and Dana are describing, go, not to 

 the terminal joints of the first antenna?, but to the frontal plates, and 

 thus correspond with the fifth pair described hj Scott. The present 

 author has not had an opportunity to examine either of the species 



described by these authors, but from 

 an examination of other species of both 

 genera it is fairly certain that the 

 branch spoken of comes from the sec- 

 ond pair of nerves, although its desti- 

 nation may vary slightly in different 

 genera. The remaining third pair of 

 nerves (3) arise from the angles of the 

 ganglion outside the second pair and 

 pass to the second antenna?. They are 

 larger than the second pair, which 

 would seem to indicate the importance 

 of these second antennas as organs of 

 prehension. In their passage to the 

 second antenna? these nerves pass under 

 the second pair. 



These are all that are given off by 

 the upper ganglion. From the frontal 

 and lateral margins of the lower gan- 

 glion arise seven pairs of nerves, while 

 three other pairs are given off from 

 the posterior end and form a sort of 

 spinal cord, thus making thirteen pairs 

 in all (fig. 28). The ten pairs from the 

 lower ganglion supply the remainder 

 of the appendages and the body muscles. 

 The first of them, the fourth pair (4) 

 in sequence, arise near the center of 

 the anterior margin, and pass along the 

 muscles of the oesophagus until they 

 reach those of the mandibles near the 

 base of the mouth. We have already 

 muscles were surprisingly large. These 



Fig. 28.— Nervous system of a Caligus 

 (After Pickering and Dana.) 



stated that the mandible 

 nerves are also of good size. 



The fifth pair (5) have their origin near the anterior angle of the 

 ganglion and pass forward to innervate the frontal plates, running 

 under the nerves going to the first and second antenna?. 



Three other pairs, the sixth, seventh, and eighth, arise close together 

 in L&peophtheirus at the anterior angle just outside the fifth pair. 

 The sixth pair (6) innervates the first maxilla?, the seventh (7) the 



