116 Part I11.—Twenty-first Annual Report 
Genus Delavalia, G. S. Brady. 
Delavalia minutissima, T. Scott, sp. nov. Pl. iv., figs. 3-10. 
Description of the Female.—The female of this species resembles the 
type-form of the genus in its general outline, and also generally in its 
structural details, but it is the smallest of any species that has yet been 
described, being scarcely ‘4 mm. {about 2; of an inch). 
The antennules appear to consist of seven joints ; the end joint is 
about twice as long as the penultimate one, but the others are sub-equal 
in length, and, as usual, become gradually stouter towards the proximal 
end (fig. 4). 
The antenne and mouth organs, being so small, were difficult to get 
hold of, and are not figured, but so far as they could be made out they 
resembled very closely those of Delavalia emula (T. Scott). 
The first pair of thoracic feet resemble in some measure the first 
pair in Delavalia robusta, Brady and Robertson, and of D. reflexa 
of the same authors, but the principal terminal spine of the inner 
branches is distinctly different, and the spine on the inner distal 
angle of the second basal joint is remarkably elongated, as shown by the 
figure (fig. 5). 
The next three pairs (figs. 6 to 8) resemble those of Delavalia emula, 
but are more slender and moderately elongated, and while in the second 
and third pairs the outer and inner branches are of nearly equal length, 
the outer branches of the fourth pair are considerably longer than the 
inner, as shown by figure 8. 
The fifth pair, though small, are, in their general character, similar to 
those of the group to which the species belongs. The basal joint is fur- 
nished with four sete on the broadly truncate apex ; a short and a long 
seta near its inner aspect and a pair somewhat similar towards its exterior 
aspect, with a distinct space between the two pairs; the secondary joints 
are each armed with four setze on the broadened, truncated end, the two 
middle setze being much smaller than the others, as shown by the drawing 
ales, 
The caudal segments are proportionally more elongated and slender 
than those of any other of the described species of the genus; these 
segments, besides being very narrow, are at least equal to the entire 
lencth of the last two segments of the abdomen (fig. 10). 
Habitat.—Moray Firth; apparently rare. No males have been 
observed. 
~ Remarks.—What first attracted my attention towards this species was 
its small size and the remarkable length of the furcal joints. It is the 
smallest species of the group that I have yet observed, and though 
apparently rare, that may be partly accounted for by its being so easily 
overlooked. The specimen from which the figures have been prepared 
was obtained in a gathering of dredged material collected in the Moray 
Firth several years ago, but the description of it was delayed in the hope 
that other specimens might turn up, which would have enabled me to present 
a more complete series of detail drawings, but this hope has not yet been 
realised. The description and figures given here are, however, along with 
the small size of the copepod, sufficient to distinguish it from those 
already described, indeed, its extremely long furcal joints would alone 
mark it out as different, and these taken along with the peculiar armature 
of the inner branches of the first thoracic feet, and also of the fifth pair, 
give to the species a character distinct from other Delavalias. 
