ACTINIAR1A 



Me. Munich (1913, p. 969) adopts. That the species of Quoy and Gaimard is a larva of Peachia ( Bici- 

 dium) is very probable; I will, however, make the reservation that this species possibly may be the larva 

 of a Halolava or of an Eloactis. Unfortunately the figure given by Pax 1 , is of so small dimensions that we 

 cannot form a clear conception of the relation between the longitudinal pennons and the parietal muscles 

 (compare below the conditions in Peachia on one side, Haloclavd and Eloactis on the other), nor of the struc- 

 ture of these latter. Judging by the figure the arrangement of the muscles rather seems to indicate that the 

 species belongs to one of the two latter genera. This might be very easily decided by an examination of the 

 apices of the tentacles and their nematocysts. There is no doubt that the type of Quoy and Gaimard be- 

 longs to some one of the above-named three genera. 



Hertwig's Halcampa clavus, on the other hand, certainly is a species of Halcampoides. Concerning 

 this species Haddon (1889, p. 336) has suggested that it is identical with Studer's Halcampa purpurea, 

 to which Kwietniewski (1896, p. 588) objects, while Me. Murrich (1913, p. 969) thinks that it may pos- 

 sibly be a larva of Halianthella (Edwardsia) kerguelensis (Stud.). The latter view is, to my mind, quite unten- 

 able, as there are pores in the physa of Hertwig's species, but no such in H. kerguelensis. Furthermore re- 

 productive organs are developed in H. clavus, and therefore it cannot be a larva. Besides this, Hertwig 

 has not observed any mesogloeal sphincter in his species, and he could not possibly have overlooked the 

 well developed sphincter of H. kerguelensis. On the other hand, Haddon is, as far as I can see, quite correct 

 in his opinion that H. purpurea and clavus of R. Hertwig are one and the same species. It is true that Kwi- 

 etniewski emphasizes that H. purpurea is furnished with a single pore in the physa, while clavus has several 

 such, but, as regards purpurea (compare above!), I do not think that this observation by Kwietniewski 

 is exact, as the physa of both forms is perforated by several pores. The difference in size between the 8 "Ed- 

 wardsia-mesenteries" and the 4 other mesenteries in H. clavus, in contradistinction to the uniform develop- 

 ment of all mesenteries in purpurea, seems to me to be of little importance as also .in the Northern forms I 

 have found the 2 youngest couples, at least of younger individuals, to be weaker than the other mesenteries 

 (Compare also Appellof 1896, p. 13). Halcampa clavus of Hertwig and H. purpurea therefore to my mind 

 are identical species. 



A third Antartic species, Halcampa kerguelensis Hertw. also seems to me to be identical with H. pur- 

 purea. It is true that Hertwig has pointed out some characters which might serve to distinguish clavus 

 from kerguelensis, but on closer critical inspection I come to the conclusion that these characters are insigni- 

 ficant. The slightly different structure of the pennons is probably connected with the different size of the 

 specimens, furthermore the transverse-sections of the pennons of H. kerguelensis, reproduced by Hertwig, 

 is in no wise typical. Such an arboriform shape of the middle part of the pennon I have never observed, al- 

 though I have sectioned a couple of specimens (compare textfigs. 107, 108). The two sphincters which Hert- 

 wig describes in H. clavus do not deserve this name; to my mind, they are, as I have above suggested, only 

 indifferentiated circular muscles concentrated through the contraction of the column in these parts. Also 

 the different appearance of the actinopharynx in both species is certainly connected with a different state 



1 Pax (1914, p. 585) seems to adopt the opinion that the species of Quoy and Gaimard is a Peachia. He declares that he 

 has proved this species to be a Peachia, which to my mind does not appear from his account. 



