588 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 4t. 



glandular layer. The latter contains many modified cells, which are 



filled with a digestive fluid, and thus take the place of digestive 



glands. In the long-necked genera that portion of the stomach, 



if any, which enters the trunk is narrowed and flattened and so 



crowded by the reproductive organs that it functions only as an 



intestine. 



THE EXCRETORY SYSTEM. 



In the Lernaeopodidae the excretory system is made up of two pairs 

 of glands. The maxilhpedal pair are on the dorsal side of the body, 

 behind the bases of the maxilUpeds. Each starts at three different 

 centers, one median and two lateral, which increase in size and grad- 

 ually fuse together. A spirally convoluted duct leads to the base of 

 the maxilliped whore it opens to the surface. The maxiUary pair are 

 situated at the bases of the second maxillae ; a straight duct leads from 

 each gland outward and opens on the inner surface of the maxilla 

 (fig. 141). 



In those genera (Clavella, Clavellisa, etc.) where the second maxillae 

 have disappeared and the bulla is on the ventral surface of the trunk, 

 the maxillary glands have migrated into the trunk and can be found 

 on either side of the buUa. This is also the case in Naohrancliia where 

 the second maxillae are present but are so modified that they can not 

 contain the glands (p. 661). 



In many species also, of various genera, the second maxillae are so 

 slender and their inner cavity is so filled with the longitudinal muscles 

 that there is httle room left for the glands. In such species there is 

 often a sweUing on the outer surface of the maxiUa near its base, and 

 in this swelling is located the gland (fig. 221) . Or the swelUng may be 

 on the side of the neck near the base of the second maxillae (fig. 109.) 



THE NERVOUS SYSTEM. 



The nervous system * consists of a very large infra-esophageal 

 gangUon and an equally small supra-esophagoal gangUon (fig. 122). 

 From the anterior end of the latter two pairs of nerves are given off, 

 one of which goes to the first antennae and frontal margin, wliile 

 the other larger pah' supply the second antennae and upper lip. 

 From the posterior end a third pair of nerves run backward along 

 the anterior waUs of the stomach, the dorsal portion of the head, the 

 frontal gland, and the maxiUipcdal gland. 



From the anterior end of the infra-esophageal gland a pair of nerves 

 run forward to the base of the lower lip and send a branch to the 

 mandibles. From the ventral surface of this ganglion a slender nerve 

 goes to the first maxilla on either side, another to the second max- 

 iUa, and from the postero- ventral corner a larger nerve runs to the 

 maxiUiped. Just in front of this last nerve a delicate nerve thread 



1 Good figures of the nervous system of both sexes were published in these Proceedings— vol. 39, 

 plate 34. 



