416 
W. N. F. W(3(JDLAND. 
of this duct opening (which have presumably shrunk away 
from the thick cuticle) are also connected with the cuticle by 
protoplasmic processes (nearly a dozen in number_, though only 
about six are shown in the drawing) developed from their 
outer ends^ which converge towards and become inserted into 
two curious plug-like bodies firmly imbedded in the cuticle 
{C. P. CoL, Text-fig. 8). These two plug-like bodies are not 
found in any other part of the body, and doubtless possess some 
special retentive function in connection with the cell-clump 
here developed. At their inner ends the cells composing the 
clump are ill-defined, and appear to merge into the numerous 
connective-tissue strands [Conn., Text-fig. 8) occupying the 
cavity of the maxilla in this region. It is possible that the 
cells of the clump represent smooth muscle-fibres (they are 
not striped transversely), which on coutractiou serve to block 
up the external aperture of the gland. It is certain that the 
clump is not glandular, developed for the purpose of secreting 
the extra thick cuticle in this region, since the ordinary hypo- 
dermis is not specially developed elsewhere to produce this 
result, and it is difficult to suppose that the clump possesses a 
sensory function, though the pigment (?) spots associated with 
the two plugs” at first suggest this. 
Some Stages in the Development of the Maxillary 
Gland. 
The Gland of the 2 mm. Larva of L y s i o s q u i 1 1 a 
eusebia. — In some Erichthus larvm of Lysiosquilla 
eusebia, 2 mm. in total length, comparable with the develop- 
mental stage figured, after Claus, by Caiman ( 3 ) in his fig. 
191a (only the second thoracic limb in my specimens has not 
yet become enlarged), and, with the exception of the “ meta- 
nauplius” stage of Lister ( 16 ), representing the youngest 
larval form of Squilla yet known, the maxillary gland is of the 
simple form represented in Text-fig. 1. The gland at this 
early stage of development solely consists of a simple, deep, 
pocket-like ingrowth opening’ at the base of the maxilla on 
