ATLANT. DEEP-SEA EXPED. 1910. VOL. III]. 



ECHINODERMATA 



Oneirophanta mutabilis Theel. 

 (PI. 2, figs. 1 & 2). 



Oneirophanta mutabilis Theel, Bih. K. Sv. Vet. Akad. Handl., 



Bd. 5, no. 19, 1879, p. 6. tab. 1, figs. 4-6. 



'%. Stat. 10, 45° 26' N., 9° 20' W., 4700 m., yellow mud, temp. 

 2.56° Cel. 10 specimens. 



The largest specimen was 108 mm. long and 47 mm. 

 broad. It had 12 tube-feet on either side, 10 lateral 

 and 6 dorsal papillae. The middle ambulacrum of the 

 trivium had 5 very small tube-feet, two of them quite 

 near the anus. The fifth pair of dorsal papillae were 

 smaller than the rest. Another specimen, 60 mm. long, 

 27 mm. broad, had 12 tube-feet on the right and 13 on 

 1he left side. The middle ambulacrum of the trivium 

 had 4 tube-feet. There were six pairs of lateral and 

 dorsal papillae. The smallest specimen, 37 mm. long, 

 15 mm. broad, had 7 tube-feet on the right and 8 on the 

 left side. The middle ambulacrum of the trivium had 



3 tube-feet. The specimen was unfortunately a little 

 mutilated, and therefore the number of lateral and dorsal 

 papillae could not be exactly determined. 



In the remaining specimens the number of tube-feet 

 varied between 10 and 14 pairs on either side. In 2 

 specimens they were arranged in distinct double rows 

 on either side. In a third this arrangement was found 

 on one side only, on the other side they formed a 

 single row. The number of lateral papillae varied between 



4 and 10 on either side, and the dorsal papillae, between 



5 and 8. In the specimen depicted (pi. 2, fig. 1.) the 

 third and fifth pair of dorsal papillae were smaller than 

 the rest. The same was the case in a second specimen; 

 in the other specimens only 5 pairs were smaller. Colour 

 in life, transparent. 



Calcareous plates and deposits agree entirely with 

 those in Oneirophanta mutabilis. I have therefore referred 

 the specimens to this species, the more as the variations 

 in the number of papillae and tube-feet come within the 

 limits given by Theel 1 ) and Ludwig 2 ) for this greatly 

 varying species. 



Oneirophanta mutabilis has a world-wide distribu- 

 tion. The "Challenger" captured it in the Atlantic region 

 off Montevideo, and the "Talisman" in the Bay of Biscay. 

 It is further known from the Indian Ocean and the Pacific, 

 Bathymetrical range, 2516 to 5307 m. The "Challenger", 

 "Blake" and "Michael Sars" found the bottom temperature 

 varying between 0.2° and 2.56° Cel. 



Laetmogone r/o/aceaTheel. 



Laetmogone violacea Theel, Bih. K. Sv. Vet. Akad. Handl., 

 Bd. 5, no. 19, 1879, p. 11, Tab, 1, figs. 14a— d. 



'%. Stat. 4. 49° 38' N., 11° 35' W„ 923 m., sand and mud, 

 temp. 9.2° Cel. Three specimens. 



5 /=. Stat. 23, 35° 32' N., 7° 7' W., 1215, m. yellow mud, temp. 

 10.17° Cel. 8 specimens. 



%. Stat. 24, 35° 34' N., 7° 35' W., 1615 m., yellow mud, temp. 

 8° Cel. 9 specimens. 



There are besides 2 specimens without definite locality. 



The "Michael Sars" took numerous specimens of this species in 

 1902 south of the Faroe-Iceland banks (stat. 76a, 59° 28' N., 8° 1' W., 

 1100 to 1300 m„ temp. 8.07° Cel., and stat. 79, 61° 7' N„ 9° 33' W., 

 750 m.). 



Laetmogone violacea is known from the Atlantic, 

 the Bay of Bengal, the Indian Archipelago, and the 

 Pacific. Within the Atlantic region it appears to have 

 its principal distribution on the east side, where it was 

 found in a number of localities from the Faroe-Iceland 

 banks to the Azores and the west coast of North Africa. 

 On the west Atlantic side it is only recorded from the 

 Davis Straits and the Bredefjord, Greenland (Mortensen) 1 ). 

 Bathymetrical range, 225 to 1739 m. Bottom temperature 

 2.2 to 10.17° Cel. 



Laetmogone wyvilli thomsoni Thdel 



Laetmogone wyvilli thomsoni Theel, Bih. K. Sv. Vet. Akad. 

 Handl., vol. 5, no. 19, 1879, p. 10, tab. 1, figs. 12—13. 



<%. Stat. 4, 49° 38' N., 11° 35' W., 923 m„ sand and mud, 

 temp. 9.2° Cel. 3 specimens. 



6 /o. Stat. 24, 35° 34' N., 7° 35' W., 1615 m., yellow mud, temp. 

 8° Cel. 3 specimens. 



25 /s. Stat. 41, 28° 8' N., 13° 35' W., 1365 m, yellow mud. 

 One specimen. 



Laetmogone wyvilli thomsoni is known only from 

 the east side of the Atlantic region, where it was previously 

 taken by the "Caudan" in the Bay of Biscay and by 

 the "Princesse Alice" off the Azores. It ranges from 

 28° 8' to 49° 38' N., while L. violacea is found from 

 20° 41' to 61° 7' N. Laetmogone wyvilli thomsoni is 

 further known from the Antarctic, the Pacific and the 

 Indian Archipelago. Bathymetrical distribution, 631 to 

 3294 m. Bottom temperature, 0.3—9.2° Cel. 



Benthogone rosea Koehler. 



Benthogone rosea Koehler, Echinodermes, Res. Sci. Camp, du 

 "Caudan", Fasc. 1, 1896, p. 114, tab. 1, figs 2, 3, tab. 3, fig. 36, tab. 

 4, fig. 46. 



Vs. Stat. 24, 35° 34' N., 7° 35' W., 1615 m., yellow mud, temp. 

 8° Cel. 5 specimens. 



Vs. Stat. 25 A, 35° 36' N., 8° 35' W., 2300 m., yellow mud. 

 10 specimens. 



'). Theel: Holothurioidea I, Rep. Sci. Res. "Challenger", Zool., 

 vol. 4, part 13, 1881, p. 62. 



2 ). Ludwig; Albatross Holothurioidea, p. 70. 



J ) Mortensen: Conspectus Faunae Granlandicae, Echinodermer, 

 1913, p. 322. 



