from the Xorth Sea and adjacent parts. 309 



arise from ringed cirropliores, wliieh arc not so large as 

 tliose of O. britaanica. The paipi arc Hattciied, but have 

 more rounded tips than those of 0. britunnica. They are 

 separated by a luediau fissure. 



The body is like that of O. brilaanica, but in many cases 

 is not so broad. There are from 50-70 segments^ and the 

 narrowest is the peristomial segment, which bears ihe ten- 

 tacular cirri towards its anterior dorsal border. The tenta- 

 cular cirri are very short and translucent in appearance. 

 None showed an extruded probosci><, a full description of which 

 will be fouiul on p. 412, vol. ii. part ii., of the Monograph. 

 The segment following the peristomium is also narrow and 

 carries the first pair of feet, uhieh do not reach so far 

 forward as tliose of O.britannira. The feet of tiic specimens 

 of this eolh'ciion agree with those described by Prof. 

 M'lntosh. In most the branchiae arise on the twelfth foot, 

 but in several, however, they arise on the eleventh foot. 

 They are simple processes, with an occasional accessory 

 filament, and continue backward almost to the tail. When 

 contrasted with those of O. brilannica, the braneliiie are 

 smaller and the dorsal cirri are more conical in outline and 

 diminish from before backward. 



Most of the tubes in this collection are formed from coarse 

 gravel and minute stones of all colours fixed to a lining of 

 the secretion, which becomes white and hard as an inner 

 coating of the tube. The tubes arc in many cases very 

 much longer than the annelids, and often the posterior 

 aperture is closed. Some specimens, however, have tubes 

 which resemble those of O. britunnica, but, instead of whole 

 shells being used, only fragments are taken along with small 

 stones or gravel. 



In no case were parasites, external or internal, found, and 

 the fieees when examined were similar to that of 0. britannica. 



Hyalina'cia tubicohi, O. F. Miillcr, 1788. 



This annelid is by far the most numerous in this North 

 Sea collection, and outnumbers all the others taken together. 

 ]\Iany forms of interest occur, some with eyes, some without 

 eyes, and some whose eyes are, as it were, in an intermediate 

 state. Again, many young forms scarcely three-fourths 

 of an inch long are included in the collection, and these 

 contrast in no small degree with others which measure about 

 6 inches long. The following is the data showing the 

 hauls : — 



Ann. c(L- }fag. X. Hist. Ser. 8. Vol xiv. 21 



