ANNELIDS. I. 67 



Otopsidae, nov. Cam. 



For the following form, taken by the Ingolf Expedition south of Iceland in a depth of 843 

 fins., it has proved necessary to establish a new family. For the moment it will be of no use to dis- 

 cuss the relationship of this form to the known groups of Polvcheats. I shall only remark that the 

 parapodium calls to mind that of the Phyllodoeidae with the restriction that compound setae are entirely 

 lacking. The cephalic lobe does not show relation to any known form. 



It is an untoward situation to be obliged to establish a new genus on a single specimen; al- 

 most impossible is it when it is necessary to draw up the lines for a new family. 



According to my opinion the characteristica of the new family will be the following: 



Forms of medium size with the body of nereidiform or euuiciform aspect, consisting of a con- 

 siderable number of segments. Body somewhat flattened; the dorsal side only a little convex, the ven- 

 tral side provided with a well marked, rather deep depression extending along the mid-ventral line 

 through about the whole length of the animal. The cephalic lobe is well developed, its longitudinal 

 axis forming about a right angle with the longitudinal axis of the body. Two tentacles (short and 

 thick) are present; in the median line of the cephalic lobe is situated a rather small, unpaired tentacle 

 (possibly a nuchal organ?). Pharynx longitudinally folded; chitinous jaws and paragnaths wanting. The 

 parapodium is well developed, long, muscular and highly movable. Acicles present in two bundles, 

 a ventral, consisting of 3, and a dorsal, consisting of 2 acicles. Dorsal and ventral cirrus developed, 

 lamellifonn. Bristles uucompound, hairy, exceedingly delicate. 



Otopsis longipes n. g. n. sp. 



PI. VI., figs. 1— 12. 



Locality : 



The Ingolf Expedition, St. 68, 62°o6' N. L., 22°3o' W. L. 843 fms. South-west of Iceland. 



Two fragments are present, evidently belonging to the same specimen. One of these fragments 

 constitutes the foremost part of the animal including the head; the hindpart of the animal is lost. The 

 two fragments together measure no mm; the cephalic fragment (PI. VI., fig. 6), measures alone 43 mm. 

 The breadth of the animal, almost the same through the whole length of the present fragments and 

 only tapering a little in the front end, is c. 7 mm. 



The shape of the animal being euuiciform or nereidiform and the hindmost segments present 

 being of almost the same breadth as the rest, it is cpiite impossible to judge of the real length of the 

 animal. It is possible that more than half of the body-length has been lost. The single segments 

 are short and broad, and the body has got a peculiar and characteristic aspect in that the parapodia 

 are not limited against the dorsum by a furrow as usually is the case with errantiate Polychaetes viz. 

 Nereids, Eunicids, Hesionids, Glycerids; the case is more like that in Polynoids and Phyllodocids in 

 which families the furrow is covered respectively by the elytra and the dorsal lamellae; but even in 

 these two families the j^arapodia are more sharply limited against the dorsum than in the species 

 under consideration. The case presents itself plainly in the fig. 6, PI. VI. 



9" 



