502 
W. T. OALMAN. 
situated at the exit from the excretory duct, that of Phyl- 
lognathopus is at its inner termination, and represents, in 
all likelihood, a modification of the coelomic sac. 
An excretory function is also ascribed to paired nephro- 
cytes, or masses of them, in the head and body-somites, and 
in the same connection there is described a pair of voluminous 
glandular masses in the last somite, with ducts opening on the 
uropods. 
Nervous System. — The central nervous system is re- 
markably bulky in comparison with the other organs. The 
large brain shows no trace of optic lobes. The ventral nerve- 
chain shows some degree of longitudinal concentration (not 
very fully described), and the ganglia are indistinctly defined 
from the connectives. 
Reproductive System. — The reproductive system of 
both sexes is simple. The gonads lie in the abdomen, and 
their ducts run forwards to open to the exterior in the 
positions characteristic of the Malacostraca, those of the 
female on the sixth and those of the male on the eighth 
thoracic somite. 
IV. Development of Bathynella. 
The only young stage observed by Chappuis (the size is 
not stated) resembled the adult, except that the last four 
pairs of thoracic limbs were rudimentary. The single pair of 
pleopods and the uropods were fully developed. This is in 
curious contrast to Koonunga, the only other Syncaridan of 
whose development we know anything, where Sayce (1908, 
p. 11) found a young specimen with all the thoracic appen- 
dages fully developed while the pleopods were still un- 
segmented buds. 
Y. The First Thoracic Somite in the Syncarida and other 
Malacostraca. 
In discussing the structure of Bathynella in 1899 I 
pointed out that it possessed eight free somites in the 
