28 ANNELIDS i 



Inoolf-Kxped. St. 40. 62°oo' N. L. 2i°36' W. L. 845 fms. South of Iceland. 



- 67. 6i°3o' — 22°3o' 975 — 



- 69. 62°4o' — 22°i7' — 589 — - - 

 - - 68. 62°o6' — 22°3o' 843 - - - 



- 25. 63°3o' — 54°25' — 582 — Davis Strait. 



Further it has been taken at 66°49' N. L. 56°28' W. L. 235 fms., Davis Strait; and at 6i°o8 N. L. 

 9 C 56' W. L. 900 m. S. W. of the Faroe Islands. Finally at 63°05' N. L. 20°07' W. L. 557 m., south of Iceland. 



Of the above named stations, all those from the Ingolf-Expedition with the exception of two 

 belong to a restricted area south of Iceland, and the last named locality belongs to the same area, 

 not far from the Ingolf-Expedition's St. 69. The station S. W. of the Faroe Islands lies somewhat 

 more easterlv. Two localities belong to Davis Strait. The depths lie between 900 and 2000 m.; only 

 one specimen originates from more shallow water, namely 557 m. 



The species lives associated with corals on which it lives. Verrill has described it from Isi- 

 della arbuscula (. Icanella Normanni). Almost the entire material at my disposal originates from the 

 same species. Only two captures, viz. from the Ingolf Stations 46 and 10, have been taken on Ai/t/10- 

 mastus grandifiorus. 



On the hidella arbuscula the worm is found sitting on the branches of the coral and making 

 use of the long and flexible hindpart of its body, which it evidently employs just as an arboreal 

 mammal does its prehensile tail; it is always the ventral side of the abdomen which turns towards the 

 branch of the coral to which the animal is attached. From the attitudes occupied by the different 

 specimens when attached to the branches of the coral and preserved together with these, it is to be 

 supposed that the worm is able to move about on the coral. I find it probable that it is also able to 

 swim, and this supposition is founded on the shape of the feet. For one thing the dorsal cirri are 

 very long, secondly the dorsal setse are few, translucent and provided with only few rows of spines, 

 the ventral setse have a relatively broad endblade. The long dorsal cirri as well as the shape of the 

 dorsal setae call to mind the corresponding organs of the pelagic living Harmothoe Hubrechti, Mc. Intosh. 

 But while the latter is a veritable Plankton-organism — , at any rate periodically — I imagine the 

 //. acanellm only swimming from one coral-bush to another, where it then takes hold of a branch with 

 its abdomen, f. i. as a Hippocampus with his tail takes hold of a plant. 



The shape of the animal is very characteristic, the hindmost part of the body being more 

 slender as well as thinner than the rest. At a first glance I suggested the abdomen of the specimen 

 under examination regenerated; but when I perceived that all the specimens present had the same 

 peculiar aspect, and that the hindmost part of the body was devoid of scales, while each segment was 

 provided with a pair of very long dorsal cirri, I became concious that the case was normal. 



The closer examination gave the following: 



The greatest specimens reach a length of e. 40 mm., a few somewhat more. In one individual, 

 the length of which was accurately 40 mm., the greatest width was c. 9 mm.; without sets only 6 mm. 

 The shape of the animal is consequently rather slender in the whole. 



Scales are present on the following segments: 2, 4, 5, 7, 9, n .... 21, 23, 26, 29, 32. The matter 

 stands thus, that the first segments behave as generally in the Polynoids, from the segment 23, we 



