HYDROIDA II 



2 9 



Gen. Cuspidella Hincks. 



Stolonial colonies, with stalkless, sessile tubular hydrothecse. The closing apparatus is formed 

 by an integrating distal portion of the hydrothecse, which folds conically over the indrawn polyp; 

 there is no distinct limitation between the closing apparatus and the remainder of the hydrotheca. 

 Nematothecse lacking. 



Cuspidella humilis Hincks. 

 1863 Cam pan 11 /aria humilis, Hincks, M. S., Alder, Supplement to a Catalogue of the Zoophytes, p. 239. 

 1866 Cuspidella humilis, Hincks, On new British Hydroida, p. 298. 



Creeping colonies with cylindrical or slightly downward tapering hydrothecse, passing over 

 without stalk into the stolons. The hydrothecse are set perpendicularly on the stolons, and are short, 

 with a closing apparatus in which 10—12 segments can be distinguished. 



The gonothecse are set on the stolons, and are of the same shape and appearance as the hydro- 

 thecse, but much larger. The gonophores develope into free medusse. 



Material : 



"Thor" 64°i6' N., 22°i7' W., depth 50 metres 

 Reykjavik, from the bottom of a well-boat. 



This unpretending little species seems to have a fairly wide distribution, and has been met 

 with from the Siberian Frozen Sea down to the Cape Verde Islands. Nevertheless, the few finds lie 

 very wide apart, probably owing to the fact that the species, from its insignificant size, easily escapes 

 observation. Its principal bathymetrieal occurrence lies in the middle portion of the littoral region. 



Gen. Lafoeina M. Sars. 



Stolonial colonies with stalkless, sessile hydrothecse and nematothecse. The closing apparatus 

 of the hydrotheca is formed by the integrating folding part of the hydrotheca, and passes over without 

 distinct limitation into the same; it closes conically over the indrawn polyp. The nematotheca has a 

 distal laterally situated aperture. 



Had/. i points out in a letter that there are possibly two genera concealed under this definition. 

 According to the drawing given by G. O. Sars, of Lafoeina tenuis (1874, tab. V, fig. 3), there seems 

 to be a diaphragm occurring in this species at the junction of the hydrotheca and stolon. Levin sen 

 (1893 p. 40) was not able to find any diaphragm in Lafoeina maxima, and I have likewise been unable 

 to find any such here; my material, however, is of such a nature that a negative result cannot be 

 considered as of decisive importance. Should it be found that certain species have a diaphragm, while 

 others lack the same, it will then doubtless be most correct to divide the genus, and a further investig- 

 ation of Lafoeina tenuis must then decide which of the two groups is to retain the name Lafoeina. 



