27 
and medusoid gonophores (Fig. 38). Later Stechow has examined 
in detail the same Hydroid (20 a, p. 31, Pl. II, Figs. 7—9); he 
has given it the name Hydrichthella epigorgia and referred it to 
the family Corynidæ. It is quite naked, without perisarc, with an 
incrusting or cushion-shaped basal coenosarc; stolons are difficult 
to see; the polypes are of three kinds: hydranths, devoid of ten- 
tacles ("Fresspolypen”, 0,8—1,3 mm. in length), and two forms of 
Wehrpolypen”, both without mouth: the one (0,5—0,8 mm. in length) 
broader, with 4—8 short capitate tentacles in a simple whorl at 
the upper end; the other (0,53—1 mm. in length) more slender and 
resembling a long capitate tentacle. The sexual individuals are 
described as ”"sporosacs”, attached singly by a short stalk to the 
hydranths; the ova (male specimens have not been found) are en- 
closed in the wall of a distinct spadix, and the envelope is pro- 
vided with four distinct radial canals. Apart from the existence 
of 2 forms of "dactylozooids” the likeness to Piil/ocodium appears 
S0 evident, that a close relatienship can not be doubted. All spe- 
cimens of Anthoplexaura from different localities and depths were 
richly beset with this Hydroid. Stechow, as already mentioned, 
has referred it to the family Corynidæ; and (20 b, No. 142, p. 152) 
he has also pointed out the close relationship to Ptilocodium and 
argues against the establishing of a new family for the latter. Also 
Hydrichthys'is referred by Stechow to the Corynidæ; in so far as 
this will prove to be well founded, our Jcathyocodium has to be in- 
Cluded in the same family. Thus this family contains the three of 
the above-mentioned four epizoic Hydroids devoid of tentacles. 
It is mentioned above (p. 2) that the triple association of the 
Hydroid IZchthyocodium with the Copepod Sarcotretes parasitic on 
Scopelus glacialis is hardly quite an accidental one. I feel most in- 
clined to consider it to be a new case of such regular associations — 
in some way or other fixed by law — which are known to occur 
among other Hydroids. That Hydroids in many cases may be found 
