88 



ACTINIARIA 



ga/ws'^specimens, reproduced in the textfigures 102 103, which were not sexually ripe, show fewer folds 

 than the pennons of ripe kerguelensis-specimens (textfigs. 107 108), and the pennons of these latter spec- 

 imens have considerably thicker folds than those of the larger ones from Greenland (Scoresby Sound), the 

 Mediterranean and Kerguelen (Germ. Tiefsee-Exp.) (textfigs. 104 106). The conformity between the pen- 

 nons of these latter specimens, and between these and the pennons of purpurea, is very great, and the pen- 

 nons of these three forms (textfigs. 104 106) are on their inside furnished with low folds which were also 

 traceable on the other reproduced sections, excepting the first one which has been taken from the youngest 

 specimen. The outer lamellar part of the mesenteries is in all specimens attached close to the outer edge 

 of the pennons. The parietal muscles, which are not expanded on the column, are strong and distinctly out- 

 lined in the reproductive region. In the textfigures 109 118 I have reproduced these muscles of several 

 specimens from different localities. However varying their appearance may seem to be, it is common to them 

 all that the folds of the muscles are weaker on the outside than on the inside. In the younger, not sexually 

 ripe specimens the parietal muscles are extended and the folds not ramificated or only inconsiderably so. 

 The extended form is distinctly conspicuous in elongatus (textfigs. 109, 113), but also in young specimens 

 from Scoresby Sound, (textfig. in, length and breadth of the animal about 0,5 cm textfig. no, length 

 of the animal about 1,5 cm, breadth 0,45 cm). The parietal muscles of the Ingolf-specimen (textfig. 116) 

 and those of the specimen from Naples (textfig. 115), of which the former are devoid of reproductive organs, 

 the latter has such, are more broad than they are long, while the others are rather expanded. The parietal 

 muscles of the largest specimens are the most richly ramificated, figs. 112, 115, 117, 118. Below the repro- 

 ductive region, where the parietal muscles begin to fuse into the longitudinal muscle-pennons they are more 

 expanded, as seen on the section from the Naples-specimen in textfig. 114. We thus find that the appear- 

 ance of the parietal muscles in the reproductive specimens varies considerably in the reproductive region; 

 in younger specimens the folds are less numerous, more thick and a little ramificated, in older ones more 

 numerous, more thin and richly ramificated. In younger specimens the parietal muscles are besides more 

 radially extended while in older ones they are more concentrated, a memento that we are not uncritically 

 to put up new species, only on basis of a different appearance of the parietal muscles. The ciliated streaks 

 are well developed and the intermediate streaks well differentiated. The median streak forms a direct pro- 

 longation of the longitudinal ridges of the actinopharynx. The cnido-glandular tract is very long. In several 

 specimens I have observed a small oral stoma. Also a marginal stoma is present. The species is dioecious. 

 Remarks: As this species has played a certain part in zoogeographical respect I have above given 

 a more than usually detailed description of its anatomy. I also would advise a stricter analysis of its rather 

 intricate synonymy. The Antarctic forms are the first to be discussed. As regards Actinia clavus Quoy and 

 Gaim. which several authors have placed in the genus Halcampa, it is evidently not identical with Halcampa 

 clavus R. Hertwig, which Pax 1912, after having examined some types of Quoy and Gaimard, was willing 

 to place together with the species of these authors. The difference in their anatomy is namely considerable. 

 The presence of a single deep siphonoglyphe in the species of Quoy and Gaimard is enough to prove that 

 we have to do with quite another genus than that of Hertwig. Andres (1883) has a more correct under- 

 standing of its systematic place as he names the former Philumcdusa ( Bicidium) clavus, which name also 



