80 Mr. C. Spence Bate on a new Species of Spheroma. 
shaped, being largest near the apex, and furnished with a row 
of plumose cilia along the outer margin. 
The fourth and fifth pairs of pleopoda have the mner and 
posterior plates converted into branchial organs, consisting of 
five or six foliaceous plates overlying one another. The poste- 
rior pair is marginal, and consists of a single branch on a.strong 
and fixed peduncle, which is produced to a point directed 
inwardly; to the under surface of this, near the middle, 
articulates the solitary ramus; this is slightly curved and 
produced to a pointed apex, and is furnished with five or six 
sharp teeth on the outer margin; the inner margin is smooth, 
and so is the inferior, both of which last are furnished with 
short fine cilia, in this offering perhaps the readiest distinguish- 
ing feature from the South American species, which has this 
appendage fringed with long and coarse hairs. 
According to Capt. Mitchell, this animal was procured “ from 
a piece of wood which had formed part of a railway bridge over 
one of the backwaters on the west coast of the Indian penin- 
sula. The wood was honeycombed with cylindrical holes, from 
about —1,th to ;2,ths of an inch im diameter, placed close toge- 
ther. In many of these holes the animal was rolled up like a 
ball.” 
The colour of the animal, as it appeared when it arrived in 
England in spirits, is not to be depended on as resembling that 
of the living creature; but it was a subdued sage-green. Its 
length is about 4rd of an inch, while its breadth is about half 
as much. Certainly these two closely allied species are among 
the largest and most powerful wood-destroyers that we know. 
Many things have been tried to protect submarme wood from 
the ravages of its many excavators; but the only things that 
appear to have any success are the red oxide of iron and creo- 
sote. The works at Portland, which have been built with wood 
saturated with the latter, are, we are informed, entirely free from 
the depredations of these creatures. 
Mahogany and probably teak wood, as well as the hemlock- 
tree of North America (which last, however, is, we believe, useless 
for most purposes), are, we are informed, exempt from their 
depredations. 
We think that there can be little doubt that these and pro- 
bably all wood-borers make the excavations for the purpose of 
food, preferring those trees that have sappy or innocuous juices 
to those of a hard or baneful nature. The mouth appears well 
adapted in this species for the purpose: the mandibles are strong 
and powerful appendages, and furnished with a rasping organ, 
while the strong posterior pairs of pleopoda are well adapted for 
the purpose of pressing the animal forward in its cavity; the 
