1919.] Chilton.—Boring Crustacea in New Zealand. 13 
Harbour Board, sent me further particulars of the damage done by it. 
He states that the animal is found in the claystone “ used in the 
harbour-works (1913) to form walls constricting the river-mouth. The 
work at the sea end consisted of concrete laid first in bales, upon which 
concrete blocks were laid with a close sheeting of timber to the river 
frontage, as shown in the enclosed photo [see fig. 11]. This sheeting 
was afterwards extended to protect the papa wall, which has, how¬ 
ever, practically disappeared on the western side ” ; and he adds that 
Captain Fletcher states the removal of the papa has been expedited by 
the action of the Isopods, whose honeycombing operations have made the 
papa very light. Blocks that had been left showed that the Isopods do not 
touch the papa where it is embedded in the river-mud, nor will they touch 
any that is not covered with water practically all the time. Mr. Esther is 
[Photo by G. A. Esther. 
Fig. 11. —Western wall, Wairoa Harbour-works, during construction, 1913-14. 
unable to state whether the degree of saltness of the water affects the action 
of the animals or not. He also states that the first two blocks of concrete 
were laid on the end of the papa wall instead of on concrete, and these 
have sunk a few feet, and Captain Fletcher attributes this to the destruc¬ 
tion of the underlying papa by the Sphaeroma. 
Sphaeroma quoyana is much larger than either of the animals previously 
mentioned, being about 12 mm. long and 7 mm. broad. It is one of the 
Sphaeromidae, and, like many other species of that family, is capable of 
rolling itself up into a ball, though not so completely as some of the other 
species can do. The antennae and legs are comparatively short, and the 
terminal appendages, or uropoda, have the outer branch serrated on its 
outer margin. Most of the segments of the body are comparatively 
smooth, though on the terminal portion of the pleon, or tail, there are a 
