HYDROIDA II 



91 



Norway; now the "Ingolf" lias added two new localities, the one being off the south-east point of 

 Iceland, the other in the eastern part of Danniark Strait, at a spot where several representatives of 

 tiie heat-loving deep-water fauna of the Atlantic have been found. The bathymetrical position of the 

 species is also somewhat doubtful: up to the present it has only been found in the middle and 

 lower parts of the littoral region. 



. _ 600 m, 



Ficr. XLIX. The occurrence of Chdocarpus bicuspis in the Northern Atlantic. 

 In the hatched region the hterature notes a scattered occurrence. 



Gen. Thecocarpus Niitling. 



Upright colonies with branched or unbranched main stem, the apophyses bearing uubranched 

 hydrocladia with several hydrotheca;. All sarcothecte immobile. The gonothecce are set in a corbnla 

 formed by a metamorphosed hydrocladium; the blades of the corbula, or ribs, have each a hydrotheca 

 near its point of origin. 



Nutting (1900 p. 106) attaches primary importance to the question whether the stem is mono- 



siphonic, a character which, even in distinction of species, is of subordinate weight; a species such as 



Thecocarpus myriophyUum (Linne) occurs in northern seas not infrequently fertile with monosiphonic 



stem, while other colonies have a polysiphonic basal part; but it is really only in southern waters 



that strong colonies of this species are found with polysiphonic stems, at any rate a couple of feet 



hicrh. This feature, then, is of little or no interest from the point of view of generic distinction ; on 

 *' 12* 



