PACKAKD.] 



ANATOMY OF NEBALIA. 



439 



larvae as antennal and shell glands, but which in the Malacostraca un- 

 dergo a substantial reduction, we find in Kebalia the anterior pair as 

 slender glandular tubes in the basal joint of the 2d antenuce. This re- 

 lation of this gland, which is absorbed in the course of the metamorphosis", 

 but in the Malacostraca, however, is generally present as a simi)le or 

 winding glandular passage, affirms further the near affinity of Nebalia 

 to the Malacostraca stem. Of the complicated shell- gland no remains 

 survive in the Malacostraca. What we are accustomed to regard in the 

 Decapoda as shell-glands is nothing more than the anterior gland which 

 belongs to the maxillary region, but opens externally on the basal joint 

 of the 2d antennai. But we can surely prove, after careful researches on 

 living Malacostracan larvse, that the rudiments or survivors of this gland 

 are situated on the sides of the maxillaj (kiefer). In the Stomapod 

 larvai I think I have found- such a survival in the shape of a simple, 

 somewhat curved glandular tube ; and also in this place the residuum 

 of the shell-muscles are preserved. The shell or adductor muscles of 

 Nebalia aj^pear to be well developed, quite as in the shelled Phyllopods. 

 On each side of the shell we observe, under the mandibles, somewhat 

 dorsally, a large round impression with an upper and under somewhat 

 curved row of muscle-facets. On the upper end of the group of mus- 

 cles, however, on the inner side of the shell, is to be found a small gland- 

 ular tube, which with a contracted neck extends to the region of the 

 maxillsB, and is surely nothing else than the survivor of the true shell- 

 gland of the Entomostraca." 



Our sections of the body of JSfebalia Mpes show that in their general 

 features the digestive canal and appendages are much as Glaus de- 

 scribes for the Mediterranean species. We were unable to get good 

 sections of the i)roventriculus or kaumagen. Plate XXXVII, fig. 6, 

 evidently passes through the stomach in front of the heart, which is much 



Pig. 66.— Section through the front end of the thorax of Nebalia bipes; ht. heart; i, intestine; nj, 

 ganglion; vni, ventral muscle; add m, adductor muscle. Author del. 



larger than the intestine (fig. i, in text). Fig. 66 (in text) is a section 

 (No. 9) through the anterior part of the thorax, in the region of the ad- 

 ductor muscle {add. m.) ; the heart (lit) is quite remote from the small 

 intestine, which is smaller than the two anterior coeca. In Fig. 67 (in 

 text) of section 14, through the same specimen at the end of the thorax, 

 the heart (lit) is of its maximum size, and now we see sections of six 



