ROLIDIDA. 129 
the back and sides, reaching down over the foot, except perhaps quite 
behind, and bearing scattered, soft, conical, pointed, tubercles, which 
are more numerous towards the border; the rhinophores are apparently 
rather short and slender, laterally flattened and retractile within sheaths, 
of which two of the marginal denticulations are enlarged; branchiz 
seven, bi- (? tri-) pinnate, non-retractile, situated around the anus, far 
back and low down; oral veil short, very wavy, the sides prolonged, 
free, and flattened ; foot broad, truncate in front, with a very indistinct 
transverse groove ; it is rounded behind, and the margin all around is 
very wavy ; colour (in spirit) transparent white, with a blue coloration 
on the back and sides ; some of the lower tubercles have a reddish or 
brownish-tinge at the base ; the rhinophores are faint-purplish, becoming 
lighter at the apex ; the branchiz are variegated with gray ; underneath 
the margin of the mantle is marked with fine close, radiating reddish- 
brown purplish lines; the foot and oral veil are yellowish-white 
(Abraham. ) 
Length, ‘8 ; breadth, °5 inch. 
SECTION— AIOLOBRANCHIATA. 
Gills various, not arranged round the vent, but usually in rows along 
the sides of the body. 
FAMILY—AOLIDID. 
Tongue narrow ; teeth in a single central series; jaws horny ; 
tentacles subulate, simple, rarely ringed, contractile; gills superficial, 
fusiform or branched, on the sides of the back ; vent lateral, on the right 
side. 
Sxb-Family—Aolidine. 
Gills in two rows on each side ; foot developed. 
Genus, PHIDIANA—Gray. 
Tentacles clavate, perfoliate ; oral tentacles subulate; gills in cross 
rows along the back; branchiz linear, crowded; caudal extremity 
slender and greatly extended ; eyes none. 
P. longicauda, Quwoy, Zc, ii., . 288, pl. 21, f 9-10. Elongate, 
graceful, very soft; apex acute; tailed; below brown; branchiz in 
many series. 
Length, 2 inches ; of the tail, $ an inch. 
Head reddish-yellow ; back brownish, also most of the branchie ; 
rest of the body is white. (Q. & G.) 
Cook Strait. 
