HYDROIDA II 



39 



males are very elongated oval, the females elongated oval to sausage-shaped, highly curved, with a 

 short c\'lindrical neck in the middle or on the basal half of the gonotheca, and on the concave side 

 of the same. Opening margin level; in the opening itself a pair of hydranths. 



Material: 



"Thor" 63°3o' N., 2o°i4' W., depth 80 metres. 



The Faroe Islands: Boronaes 13 miles in N75W., depth 30 fathoms. 



On a previous occassion (1913 p. 13) I stated that FTalrciiiiu Bnn/ii should be regarded as a 

 variant of Halcciim/ haleciiinni\ further investigations have, however, shown that this is not correct, 

 even though the two species, more particularly 

 in a sterile state, may often enough be difficult 

 to distinguish. Fertile female colonies are not 

 easily confused, the form of the gonotheca; being 

 typically different; in comparison with the follow- 

 ing species it should be noted that the aperture 

 in Ilalcciuin Bt'duii lies roughh' in a line with 

 the basal and distal end of the gonotheca, and 

 that the neck axis closely approaches, if not entirely 

 coinciding with, this line. (Fig. XIII). The bran- 

 ches are, in Haleciimi Beanii, often slenderer than 

 in HaleciiDii halecimim and Haleciiini scufuni, and 

 the apophyse is somewhat more marked; in addit- 

 ion, the basal chamber of the secondary hydro- 

 theca is symmetrically developed, and not asym- 

 metrical as in Halcchun halrci)iu»i\ finally also, 

 the oblique position of the hydrotheca aperture as towards the axis serves to distinguish Haleciuni 

 Beanii from the two related species mentioned. 



The geographical data for Halviiuni Bfanii are extremely unreliable as regards the northern 

 waters; the species is, as I have frequently been able to perceive, often confused with Halccium scutuni 

 in arctic, with Haleciuni lialcciintin in boreal areas. In all probability, it is a heat-loving form, which 

 exceptionally penetrates into the northern waters. 



Fig. XIII. Halecitim Beanii. 



a. Inteniode with hydrotliecae. b. Gonotheca 5. From the 



Faroe Islands, Bor6iia;s i,^ miles in N.75\V. X 60 • 



Halecium scutum Clark. 



1876 Hah-cinm scufiiui, Clark, Report on the Hydroids Alaska and the Aleutian Islands, p. 2io, 



pi. 10, figs. 13—14. 



Robust colonies with polysiphonic main stem. The outermost small branches exhibit an almost 

 regular pinnate ramification in the same principal plane as that in which the branching of the colony 

 falls; more rarely, the colonies may be quite irregularly bushy. The minor branches are divided up 

 into internodia, the length of which is about twice the distal breadth (apophyse included). The primary 



