8 4 



HYDROIDA II 



sinuous. The iuternodial ribs of this variety are also somewhat more strongly marked than in the 

 common form, and it likewise shows a more pronounced indication of intrathecal septum. 



The features mentioned, that the species can at times lack phylactogonia, show that Clado- 

 carpus Pourtalesi must be considered as a synonym. The difference between this species and Clado- 

 carpus Holmi is not apparent from Levinsen's description of the latter (1893 p. 67) and an investig- 

 ation of the type specimens shows that the species has been founded on typical colonies of Clado- 

 carpus integer. 



60 



6 oc 



Fig. XLIV. The distribution of Cladocarptts integer in the northern Atlantic. 

 In the hatched regions the literature denotes a scattered occurrence. 



The species is a typical warm atlantic form, which appears to have its chief occurrence in the 

 western Atlantic, in the lower part of the littoral region and the upper part of the abyssal. In northern 

 waters, it has long been known from the west coast of Norway, and is also found to be a not alto- 

 gether infrequent visitor to Greenland, both in Davis Strait and up towards Danmark Strait (fig. XLIV). 

 On one occasion, it was met with off the east coast of Iceland, at the boundary of the arctic deep 

 region. That it has not yet been located with certainty between the British Isles and Iceland must 

 be due to accident. Ritchie (1912 p. 228) had before him a specimen brought home by Hull trawlers, 

 and we may doubtless presume that it would then have originated from the northern slope of the 

 North Sea plateau or from the Faroe Islands Banks. 



