ACTINIARIA 



tain criterium if the spirocysts are very rare or absent) speaks for the opinion that this species may form 

 the type of a new genus, because all other known Halcuriidae have spirocysts in their column-ectoderm. 

 I propose for this new genus the name Halcuriopsis and give here a preliminary diagnosis based on the 

 description by Stephenson: 



Elongated Halcuriidae, not distally lobated. Column smooth without papillae and spirocysts. Ten- 

 tacles short, conical, without thickenings of the mesogloea at the outer side of the base, comparatively few. 

 Arrangement? Longitudinal muscles of the tentacles ectodermal, not strong. Only one siphonoglyphe. 

 Mesenteries comparatively few, the older with strong muscle-pennons, to the stage of 20 mesenteries deve- 

 loped as in Halcurias, from this stage new mesenteries originate, probably in only 8 development-zones 

 on both sides of the 4 mesenteries of the second cycle. Both mesenteries of the same pair equivalent. 



Genus Actinernus Verr. 



Diagnosis: Halcuriidae with thick cylindrical body, in the distal part more or less increasing in 

 breadth and often forming distinct lobes commonly 8 in number. Sometimes these lobes are only indicated 

 or wanting in young individuals. Tentacles of ordinary length, conical or cylindrical, excepting the youngest 

 (and in A. elongatus also the inner ones?) cannot be covered by the column; on the outer side with very thick 

 mesogloea which continues bridgelike in the mesogloea of the column. The arrangement of the tentacles 

 more or less distinct, not frequently like that of Halcurias. For the greater part the tentacles are concen- 

 trated in two cycles with the largest tentacles in the apex of the lobes. Oral disc wide, especially where di- 

 stinct lobes are present, more narrow between the lobes, with weak, radial ridges and shallow furrows 

 between. Actinopharynx well developed with rather numerous, deep, longitudinal furrows and 2 broad 

 siphonoglyphes, to which several mesenteries are attached. Mesenteries numerous, arranged in the begin- 

 ning as the older mesenteries of Halcurias, after the stage of 20 mesenteries or a little later the mesenteries 

 originate bilaterally, in 8 or some more development-zones, situated between the distal lobes. The develop- 

 ment of the mesenteries goes on mostly from the edges of the endocoels towards their middle. The bilateral 

 pairs consisting each of one micro- and one macro-mesenterium. Dioecious. 



Actinernus nobilis Verr. 

 Actinernus nobilis n. sp. Verrill 1879 P- 474- 



Verr. Verrill 1885 p. 534 fig. 23, Andres 1883 p. 584. 

 Carlgren 1914 p. 70. 1818 p. 32 textfigs. 8 10, 25. 



Diagnosis: Body cup-like, short, toward the distal part forming 4 greater and 4 smaller, alter- 

 nate lobes. The lobes sometimes (often?) show a tendency to divide into feeble, indistinct, secondary lobes. 

 Mesogloea-bridges on the outer side of the tentacles broad, somewhat depressed from without inwards, teeth- 

 like, rather short and sharp-pointed in the apex. Distal parts of the tentacles of normal appearance, conical, 

 in the summit pointed, not sulcated, or feebly lengthwise so. Arrangements of the tentacles indistinct, at 



