TETRAGONICEPS. 67 
apical setz; inner branch of the second and third 
pairs (fig. 9) not very much shorter than the outer 
branch, that of the fourth pair (fig. 10) less than half 
as long; except a small, weak spine at the apex of 
each joint of the outer branch, the feet are entirely 
without spinous appendages; each branch, however, 
bears three apical setze, and the first joint of the inner 
and the second of the outer branch have each one 
seta. The fifth foot (fig. 11) is very large, consisting 
of a single long, somewhat sternum-shaped joint, 
broad at the base, then suddenly constricted and 
tapering abruptly to the pointed apex; three or four 
marginal setz on the basal portion, and one towards 
the apex. The caudal sete are short, the longest 
being shorter than the abdomen. Length g'gth of an 
inch (9 mm.). 
Three specimens only of this interesting species 
were found amongst dredged material from a depth of 
twelve fathoms inside St. Agnes (Scilly Islands). Its 
characters are so remarkable as to need no comment. 
The generic name Tetragoniceps was applied first in 
MS. to this species, but afterwards erroneously to 
Laophonte thoracica* (‘ Tetragoniceps longiremis”’). 
So far as this latter species 1s concerned, the new 
generic name necessarily lapses. 
* Brady and Robertson, ‘ Brit. Assoc. Report,’ 1875, p. 196. 
