2o0 Proceedings of the Koyal Physical Society. 



This species has been recorded from the Norwegian coast — from 

 Hvitingso and Bodo, at depths between 80 and 100 fathoms (G-. 0. 

 Sars, loc. cit.) ; from Stavanger to Bodo, 100-200 metres (Bonnevn ) x ; and 

 from Skarnsund, 100-200 metres (Jaderholm) 2 . The provenance of the Hull 

 specimen is unknown, Mr Thompson being unable to state whether the 

 trawler had been at work in the North Sea or off Iceland. 



Nutting 3 refers to the resemblance between this species and Clado- 

 carpus ppurtalesii, Verrill, so far as the hydrothecse are concerned, and 

 instances as points of distinction the presence, in Sars' figure of H. integra, 

 of unprotected gonangia, and of a row of hydrothecse on the anterior tube of 

 the stem. While the former distinction holds, placing Sars' species in genus 

 Halicornaria, the latter is in fault, for hydrothec?e occur only on the hydro- 

 clades, and Sars' figure (pi. ii. fig. 13) errs in showing them on the stem. A 

 further distinction, however, applicable to the hydrothecte, lies in the fact 

 that that portion of the hydroclade internode which lies proximal to the 

 hydrotheca is considerably longer in Halicornaria integra than in Cladocarpus 

 pourtalesii, and in the former contains not only the septum cutting off the 

 mesial sarcotheca, but also a strongly developed septum near its base. 



It is noteworthy that this species, in possessing a fascicled stem, a 

 posterior intrathecal ridge, and septal ridges in the hydrocladial internodes, 

 differs from the several American species, and overthrows the majority 

 of the characters regarded by Nutting (1900, p. 126) as distinctive of the 

 trophosome of Halicornaria. 



1 Bonnevie, Norwegian North Atlantic Expedition, " Hyclroida," Christiana, 1899, p. 93. 



2 Jiiderbolm, Kungl. Svenska Vet.-Ak. Handl., Bd. 45, i., 1909, p. 109. 



:! Nutting, "American Hydroids," pt. i., " Plunmlaridas " (Smithsonian Spec. Bull.), 

 Washington, 1900, p. 117. 



{Issued separately, 25th 'January 1912.) 



