46 



lobe is still more strongly drawn out, nearly tongue-shaped, and projects over the first seg- 

 ment nearly to its posterior edge (see fig. 20 & 22). There is however no trace of any real 

 caruncula. Eyes are also entirely wanting. 



The head is (see fig. 22) furnished with 5 rather short cylindrical, or filiform appen- 

 dages, of a very similar form and nature; 2 pairs and 1 single. The last appendage repre- 

 sents the tentacle, and is situated on the middle of the posterior tongue-shaped strongly 

 convex part of the head-lobe. Its length is somewhat less that the width of the head. The 

 anterior paired appendages represent the antennae, and proceed, rather near together, from 

 the anterior border of the head-lobe; they correspond exactly, as well in form as in size 

 with the tentacle. The 2". d pair, which represents the palpse, project on each side from the 

 part where the head-lobe has its greatest width, or about the middle of its length, and are 

 a little longer than the antennae and the tentacle. 



The 1 s . 1 bristle-bearing segment has a dorsal and a ventral filament of the same form 

 as the appendages of the head; the ventral, also of the same length; the dorsal a little longer. 

 On the following segments both these filaments become rudimentary (see fig. 31. 32, 33) only 

 representing a short conical process; on the 3 last segments they become however (see fig. 

 21) again somewhat longer, although not nearly so long as on the first segment. 



The mouth, which forms a longitudinal slit, has (see fig. 24) its place under the head 

 and 1 s .' segment, and is bounded by 4 fleshy lobes or lips, of which the posterior ones espe- 

 cially are atrongly prominent (see fig. 23). 



In spirit specimens one often sees (see fig. 19 & 20) the short fleshy gullet or pro- 

 boscis evaginated; its borders are irregularly lobed, but without any armament of teeth. 



The anus is (see fig. 21) terminal, and covered below by. a half-oval lobe. 



The gills are, unlike those of the other Amphinomes, only confined, to the anterior 

 part of the body, while they are wanting on all the other part. Usually there are only 5 

 pairs (see fig. 19) which take their beginning on the 4'! 1 bristle-bearing segment, and are 

 always arranged in pairs on this and the 4 following, one on each side of the back (see fig. 

 22 & 30). They are tolerably large, exceeding in length half the width of the body, and when 

 extended backwards, partly lap over each other, nearly covering the dorsal side of those seg- 

 ments on which they are situated. In form they are (see fig. 25 29) wide-fan-like, placed 

 transversely, 2 4 times dichotomically divided, with the last branches very short and simply 

 rounded at the end. Usually they increase in size from in front backward, becoming gra- 

 dually more strongly divided; the difference between the 3 last being however smaller than 

 between these and the anterior pairs. In the -more closely examined specimen, each of 

 the 2 primary halves of the 1 s ! pair of gills (fig. 25) consisted of 3 terminal branches; only 

 the interior branches produced by the secondary division having divided themselves fork-wise, 

 while the other branch was still undivided. In the next pair of gills (fig. 26) both the se- 

 condary branches were forked on the one side (the gill was thus here 3 times dichotomically 

 divided) ; and on the other side there was an indication of a 4"; dichotomy, the interior secon- 



