HYDROIDA II 



Greenland: Davis Strait, depth 80 fathoms (without further details) [type specimen of Clado- 



carpus Holii\ 

 Iceland: 5 miles E. of Seydisfjord, depth 135 fathoms (labelled Cladocarpus Holmi\. 



Cladocarpus integer has led a somewhat unsettled existence in various genera. G. O. Sars 

 (1874 p. 100) regarded it as an Aglaophenia, and is followed by Bonnevie (1899 p. 93) who places 

 all northern Aglaophcniida in this one genus. Jaderholm (1909 p. 109 and no) refers to it either 

 as Halicornaria integra or as Cladocarpus Holmi and Cladocarpus Pourtalesi, while Ritchie (1912 p. 

 228) classes the species under Halicornaria. A very rich material from the Trondhjem Fjord, where 

 the species is found in great numbers, enabled me to study it further, and determine its systematic 

 position. And it now turns out that the species must be regarded as a primitive Cladocarpus. The 



Fig. XLIII. Cladocarpus integer. 



a. Basal parts of a hydrocladium and its phylactogonium with an entire 

 gonotheca, from the Trondhjem fjord (X 40). b. Hydrotheca of the 

 same colony (X 60). c. Hydrotheca of a colony from "Ingolf St. 98 



(X6o). 



gonothecae are very often fixed to the stem or more correctly, to the apophyses; Ritchie's descrip- 

 tions show that this may often occur on the whole for an entire colony, and that the phylactogonia 

 may in consequence be altogether lacking, which is also exceptionally found to be the case in some 

 of the colonies from Trondhjem Fjord. The great majority of the colonies have, however, at any rate 

 in considerable parts of each, developed primitive but typical phylactogonia (fig. XLIII a). These pro- 

 ceed from the basal internodium of the hydrocladium beside the proximal sarcotheca. The phylacto- 

 gonia are practically always unbranched, and furnished with two somewhat onesidedly arranged rows 

 of sarcothecse, set either in pairs or irregularly placed; only once or twice have I found phylactogonia 

 which had, by dichotomic division, developed a short lateral branch of the same structure. The phylac- 

 togonium also exhibits irregular segmentation. It has as a rule two or three gonothecae on the same 

 side as the sarcothecse. The gonotheca is of the typical Cladocarpus form, with upper lip; this is, 

 however, shorter than in most other species, so the opening is not yet directed downwards. 



Ritchie's specimen (1912 p. 228) should, it would seem, be taken as the representative of a 

 special variety Ritchiei nov. differing from the typical form in having the hydrotheca margin slightly 



