868 The Crustacean Nebalia and its Fossil Allies, [November, 



ganglion of N. bipes (PI. xnr, Fig. 9, or Fig. I, in text, ng) shows 

 a form of ganglion quite unlike that of the Estheria and other 

 Phyllopods, in which the ganglia are separate, connected by 

 rather long transverse commissures, whereas in Nebalia the pair 

 of ganglia are consolidated and of the form of the Decapod 

 ganglion, as also pointed out by Claus, who says that there is a 

 very close resemblance in the form of the nervous centers to the 

 ventral ganglionic chain of the Mysidae. 



We have endeavored to obtain good sections of the brain of 

 Nebalia bipes, and Fig. 1 in the text will serve to illustrate toler- 

 ably well the form and intimate structure of the supra-cesopha- 

 geal ganglion. The brain is very small, and the section repre- 

 sented was the third from the front of the head. The ovaries [ov) 

 pass into the head, the end of each ovary overlying the brain. 

 The brain itself is composed of two lobes closely united, and seen 

 in section the brain is as deep as broad, with a constriction pass- 

 ing around the outside in the mid- 

 ^ die. The histological structure is 



f~ m very simple, with nothing approach- 

 ing the complex nature of the Deca- 

 *""Sp^ /• '• ( podous brain. 



W In the digestive canal, says Claus, 



/ we have a quite specific peculiarity, 



|| I together with approximations some- 



' ^ times to the Amphipoda and Iso- 



,\^^/^ eC ^"ovLr e ^ni«^ poda ' and sometimes to the M y sidse 

 t 'to show and Podophthalmata. The short 



e gang ion ce s. Aut or e . up-curved oesophagus leads into a 



stomach with a complicated chitinous armature, in which an an- 

 terior and a posterior division can be distinguished. 



Our sections of the body of Nebalia bipes show that in their 

 general features the digestive canal and appendages are much as 

 Claus describes for the Mediterranean species. We were unable 

 to get good sections of the proventriculus or kaumagen} Plate 

 xiv, Fig. 6, evidently passes through the stomach in front of the 

 heart, which is much larger than the intestine (Fig. 2, /, in text). 

 Fig. 2 (in text) is a section (No. 9) through the anterior part of 

 the thorax, in the region of the adductor muscle {add. m) ; the 

 heart {lit) is quite remote from the small intestine, which is 

 smaller than the two anterior cceca. In Fig. 3 (in text) of section 



^ur Sections were kindly made by Mr. Norman N. Mason of Providence, R. I. 



