ACTINIARIA 



229 



Habitat: 



GuUmar fiord 



Ingolf-Exp. St. 65 



Michael Sars-Exp. St. 76 . 



Baffin Bay 



Maine Bay 



Riuck-Exp. St. 5 



Japan 



Bohuslan (a little young) 



Column 

 a 



Distal part of the tentacles 

 a b spi. 



actinopharj'nx 



19-22 X 2 fl 

 22-24 >^ 2 



17-19(29) X 1,5-2 



19-22 X 2 



26 X 2 — 60 X 5 /* 



26 X 2 72 X 4.5 



24 X 2 — 62 X 5 



—67x4,5 

 24x2 — 70x4,5 



24 X 2 — 67 X 4-4,5 

 22 X 2-65 X 4,5-5 



24 X 5 yU 

 22-26X5 

 21-23X4 

 22-26X4 

 22-26X4,5 

 22-24X4-5 



24X5 

 14-22X3,5 



In my description of the species (1893) I have stated that no marginal stomata are present. They 

 may, however, appear, though not regularly. 



Remarks. As I have above put forth, I regard Stephenson's atrosioma as identical with A. callosa. 

 On the other hand, I have not added Hertwig's Dysactis crassicornis to the list of synonyms. It is true 

 that it is very nearly related to A. callosa, but it has a much stronger sphincter and a thinner colunui than 

 the real A. callosa, which I have ascertained by examining one of the tj^pe-specimens. At present I dare 

 not place these two species together. In contradistinction to Mc. Murrich (1893) and Rees (1913), who 

 tliink that they are identical, I have not added the species from the West coast of North America, described 

 by Mc. Murrich as A. callosa, either. Probably this species is the same as Hertwig's species. That A. cal- 

 losa nevertheless has a large distribution, is proved by its occurrence at Japan. 





Actinostola abyssorum (Dan.) Carlgr. 

 Bunodes abyssorufii n. sp. Danielssen 1890 PI. 3 fig. 3. PI. 10 figs. 8 — 9. 

 Actinostola abyssorum n. sp. Carlgren 1893 PI. i figs. 5, 10. PI. 8 figs, i, 2, 7, 8, 11. PI. g fig. 4textfigs. 14 — 17. 



Diagnosis: Pedal disc wide, of about the same breadth as the length of the body. Column thick- 

 waUed with longitudinal and transversal furrows, whereby tubercle-shaped thickenings arise, which are the 

 largest at the middle. Margin as in A. callosa. Sphincter long, but narrow, not concentrated, distinctly 

 stratified, reticular, forming very thin meshes. Tentacles to about 300, hexamerously arranged, conical, irregu- 

 larly wrinkled, with distinct orifice at the apex, not bulbously swoUen at the base, the inner considerably 

 broader and longer than the outer. Longitudinal mesogloeal muscles of the tentacles and the greater part of 

 the mesogloeal meshes of the oral disc are very finely di\aded. Both mesenteries in the pairs of mesenteries 

 of the third cycle of about the same size. Parietobasilar muscles strong, almost reaching the proximal end of 

 the sphincter. Marginal and oral stomata present. Dioecious. Reproductive organs on the mesenteries from 

 the third cycle. Nematocysts of the column 22 — -26 X 1,5 — 2 fi, those of the distal part of the tentacles 

 32 — 38 X 1,5 ^andthoseof theactinopharynx24 — -31 X 1,5 (2) /i. Spirocysts of the tentacles from 17 X 1,5 /* 

 to 65 X 5 fx. Large stinging capsules in the tentacles very sparse 48 — -53 X 5 — 6 fj., scarce nematocysts 

 with discernible basal part to the spiral thread in the actinopharynx 24 — 27 X 4, 5 /^. 



Colour. Column white with a mother-of-pearl lustre, shading off into pale reddish or bluish tinges. 

 Tentacles Havana-brown. Oral disc of the same colour as the column, perhaps slightly darker, and from the 



