PACKARD.] ANATOMY OF NEBALIA. 439 
larvee as antennal and shell glands, but which in the Malacostraca un- 
dergo a substantial reduction, we find in Nebalia the anterior pair as 
slender glandular tubes in the basal joint of the 2d antennez. ‘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 simple 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 2dantenne. But we can surely prove, after careful researches on 
living MalJacostracan larve, that the rudiments or survivors of this gland 
are situated on the sides of the maxille (kiefer). In the Stomapod 
larve 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 appear 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 
maxille, and is surely nothing else than the survivor of the true shell- 
gland of the Entomostraca.” 
Our sections of the body of Nebalia bipes show that in their general 
features the digestive canal and appendages are much as Claus de- 
scribes for the Mediterranean species. We were unable to get good 
sections of the proventriculus or kawmagen. Plate XXXVII, fig. 6, 
evidently passes through the stomach in front of the heart, which is much 
Fic. 66.—Section through the front end of the thorax of Nebalia bipes; ht, heart; 7, intestine; ng, 
ganglion; vm, ventral muscle; add m, adductor muscle. Author del. 
larger than the intestine (fig. 7, 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 (ht) is quite remote from the small 
intestine, which is smaller than the two anterior ceca. In Fig. 67 (in 
text) of section 14, through the same specimen at the end of the thorax, 
the heart (ht) is of its maximum size, and now we see sections of six 
