ACTINIARIA 



teries (fig. 154) have no pennons and their muscles recall the parietal muscles of the first cycle. The longitudinal 

 muscle-pennons of the first 6 pairs are in the reproductive region provided with numerous high folds, ramificated 

 in the outer and inner parts (textfig. 153). The lamellar outer part of the mesenteries is attached to the outer 

 edge of the pennon. The parietal muscles are in transverse-sections very elongated, with rather low folds, 

 sparse and only a little branched or not at all so, on the longitudinal muscle-side passing into the pennon, but 

 not expanded upon the column. The parietal muscles of the specimen from Bear Island and still more of that 

 from the Vega-Expedition are of a more robust appearance than the reproduced section of the specimen 

 from Greenland (in the Vega-specimen the main lamella of the mesogloea is considerably more thick), prob- 

 ably at least partly because of a different state of contraction. They moreover greatly recall the parietal muscles 

 of Acthelmis intestinalis. The mesenterial filaments are only present on the mesenteries of the first order 

 and on the distal part of the second one. The ciliated streaks are of usual appearance. The acontia observed 

 in sectioned specimens from all habitats are rather numerous, in transverse-sections broad and provided 

 with very numerous nematocysts (textfig. 154 ac). In the specimen from Bear Island there are, as far as 

 I can see, in the perfect mesenteries large marginal stomata near the oral disc. Concerning the reproductive 

 organs I observed ovaria in two more closely examined specimens. They appeared only on the mesenteries 

 of the first order and in the distal part of the second one. 



Remarks: The specimens dredged off Greenland (without distinct locality) and belonging to the 

 museum of Copenhagen were labelled Ilyanthus(?) arcticus. Liitk. They are evidently one of the two Ilyanthus- 

 species which I/iitken (1875) mentions from Greenland, though never describing them. They were rather 

 badly preserved while the other specimens were in better condition. For the anatomical description I have 

 used specimens from all habitats. 



Fam. Andwakiidae. 



Diagnosis: Athenaria with elongated, cylindrical or low, conical column. Proximal body-end 

 forming either an ampullaceous physa or a wide flattened base, recalling a pedal disc. Sometimes with cin- 

 clides? Sphincter mesogloeal, well developed. Acontia present. 



The preliminary diagnosis of this sub-family, proposed by myself 1893 (p. 38) -- I then regarded 

 it as a sub-family differed considerably from the first diagnosis of the family, given by Danielssen (1890). 

 In fact Danielssen's diagnosis was so extensive that it would include almost all the then described Acti- 

 ninae being devoid of a pedal disc. Danielssen in his diagnosis neither mentions the presence of acontia 

 nor the occurrence of a mesogloeal sphincter, two characters of great importance to the limitation of the 

 family. Perhaps Danielssen comes nearer to the mark when speaking of the systematic placing of the family. 

 According to the Norwegian author the family namely forms a transition stage between the Edwardsids 

 and the Sagartids (the Phellidae). Among the Athenaria the family is, according to me, most nearly related 

 to the family Halcampidae with which it has several characters in common, such as the exterior habitus 

 of the body, the occurrence of "Halcampa -papillae" and few perfect mesenteries, the absence of basilar 

 muscles and the presence of a mesogloeal sphincter. With the Phellidae, on the other hand, it agrees for 

 instance in this that acontia occur. Probably we may regard such forms as the Andwakiidae as transition 



17* 



