50 
THE VOYAGE OF H.M.S. CHALLENGEPx. 
The head agrees for the most part with that of Lcetmonice j^^'oclucta, var. willemoesi, 
and the tentacle differs from the Zetlandic form ^ in its greater length. The ocular 
peduncles are fairly developed and rounded. The scales amount to fifteen pairs. 
The dorsal setae (PI. Va. fig. 5) show three recurved fangs on one side and four on 
the other, sometimes four on both, and differ from the Zetlandic species in being less 
flattened in the shaft, less rajDidly diminished at the tip, and in being differently curved ; 
moreover, their shafts are devoid of the prickles usually seen thereon. In contrasting the 
tip of the Zetlandic form (PI. Va. fig. 7) with this (PI. Va. fig. 6), the rapid and great 
diminution is very apparent. The latter depends to some extent on the larger flattened 
shaft of the British representative. 
The ventral bristles (PI. Va. fig. 8) again diverge from any of the others (and 
especially from the British form) in having the pinnae of the tip prolonged downward so 
as to touch in many cases the origin of the spur at the end of the shaft. There is usually 
a very clear interval in allied forms. Moreover, there is not much difference between the 
pinnae at the tip and those next the spur. The latter is also very acute. The terminal 
hook is more decided than in the previous varieties. 
The intestinal canal in most was empty, but in one a brownish granular membranous 
mass like a shred of a Salpa or other gelatinous invertebrate was present. 
The ventral surface has a somewhat numerous series of ovoid papillse. The nerve- 
area is indistinct in the preparation, and in the deep-sea forms seems to be more or 
less atrophied. 
Lcetmonice japonica, n, sp, (PI. VIII. fig. 1 ; PI, IVa. fig. 13 ; PI. Va. figs. 9, 10). 
Dredged at Station 232 (south of Japan), May 12, 1875; lat. 35° 11' N., long. 
139° 28' E. ; depth, 345 fathoms ; bottom temperature 41°T, surface 64°'2 ; green mud. 
The single example is about 30 mm. in length and 13 mm. in breadth. The number 
of segments is thirty-six. 
The dorsum is wholly covered with a coat of felt much impregnated with sand, which 
also invests the hairs on the sides. The pale, smooth scales are thus completely hidden. 
The head is broad and rounded in front, narrow behind, and with a pit on each side 
of the nuchal ridge posteriorly. The base of the tentacle alone remains. The ocular 
peduncles are large and globular, and though no eyes are visible, a slight ring is present 
on the anterior convexity of the peduncle. 
Such of the great dorsal spines as remain are of a dull brownish hue with the usual 
iridescence. The shaft is considerably flattened, and has very distinct prickles thinly 
scattered over it, while the tip gently tapers (thus differing from the Zetlandic form) to 
a point, which usually has two recurved fangs on each side (PL Va. fig. 10). A few show 
1 Lcetmonice filicornis, Kbg. 
