HYDROIDA II 



83 



Greenland: Davis Strait, depth 80 fathoms (witliout further details) |type specimen of Clado- 



carpus Holini\ ' 

 Iceland: 5 miles E. of Seydisfjord, depth 135 fathoms |labelled Cladocarpits Holmi\. 



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

 (1874 p. 100) regarded it as an Aglaoplieiiia^ and is followed b}- Bonne vie (i8gg p. 93) who j)laces 

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

 as Halicornaria iiitegra or as Cladocarpus Hohiii and Cladocarpits Poitrtalesi^ while Ritchie (191 2 ]). 

 228) classes the species under llalicoriiaria. A very rich material from the Trondhjeni Fjord, wliere 

 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. Cladocarpua integer, 

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

 gonotheca, from the Trondhjem fjord (X 4o). — *• Hydrotheca of the 

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



(X 60). 



gonothecse 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 colons', 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). The.se pro- 

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

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

 of sarcothecEe, 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 gonotheca; on the same 

 side as the sarcothecte. 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 Ritchicl nov. differing from the t>pical form in having the hydrotheca margm slightly 



