OPHIURANS OF UNITED STATES NATIONAL MUSEUM. 31 



OPHIOMUSIUM VALIDTJM Ljungmau. 



Ophiomusium validum LJUNOMAN (71), p. 618. 



Ophiomusium validum LYMAN (78), p. 114. 



Ophiomusium validum LYMAN (78o), p. 219, pi. 5, fig. 9. 



Ophiomusium validum LYMAN (82), p. 92, pi. 1, figs. 1-3; pi. 39, figs. 11-13. 



Ophiomusium validum LYMAN (83), p. 246. 



Ophiomusium validum KCEHLEK (97), p. 307. 



Ophiomusium validum KCEHLEK (99), p. 25. 



Ophiomusium validum H. L. CLARK (01), p. 244. 



Ophiomusium validum KCEHLER (04), p. 59. 



Ophiomusium validum KCEHLER (07), p. 297. 



Albatross station 2350. Jan. 20, 1885. Lat. 23- 10' 39" N.; long. 82 20' 

 21" W.; 213 fathoms; co. One specimen. 



Albatross station 2636. Apr. 7, 1886. Lat. 23 10' 45" N.; long. 82 18' 

 45" W.; 191 fathoms; dead. co. sh.; temp. 62.6 F. One specimen. 



Albatross, 1886. Off Havana; no depth mentioned. One specimen. 



The diameter of the disk ranges between 9 and 13 mm. 



In the drawings of 0. validum published by Lyman, the two radial shields 

 of each pair are represented as being in contact on almost half their length, but 

 in the descriptions given by the same writer, it is not definitely stated whether 

 the radial shields are contiguous or separated; Lyman simply writes that "they 

 are strongly diverging inward and separated by a triangular scale." Lyrnan 

 made his description after a specimen, the disk of which was 8.5 mm. in diameter. 

 Now, in the three specimens in hand, the radial shields are separated on their 

 whole length by several successive plates, and in the largest specimen (off Havana), 

 the two internal or radial sides of the shields of each pair are parallel and the 

 interval which separates them is just as wide as the interradial space. In the other 

 two examples, the radial shields are lying closer distally, even more so in the sample 

 from station 2350, and they are slightly diverging. The arrangement of the radial 

 shields may therefore vary as the age increases. In Ljungman's type, the disk 

 of which was 12 mm. in diameter, the radial shields were "sejuncta intus paullum 

 divergentia." * The other characters of my specimens are quite in accordance with 

 Lyman's description and there can be no doubt as to their determination. Besides, 

 I have already had the opportunity of pointing out a few variations in the arrange- 

 ment of the plates of the upper face of the disk in some specimens from the Indian 

 Ocean (97, p. 307; 99, p. 25; 04, p. 59), and H. L. Clark also made similar remarks 

 regarding the examples which came from Porto Rico (01, p. 244). 



0. validum has been found in a great many localities in the Caribbean Sea, 

 between 60 and 1,518 fathoms. The Investigator met with it north of the Laccadive 

 Islands (931 fathoms), and the Siboga in Moluccan waters (230-600 fathoms). 



OPHIOMUSIUM ARMIGERUM Lyman. 



Plate 3, fig. 1. 



Ophiomusium armigerum LYMAN (78), p. 109, pi. 1, figs. 21-22. 

 Ophiomusium armigerum LYMAN (82), p. 86, pi. 2, figs. 7-9. 



Albatross station 2754. Dec. 5, 1887. Lat. 11 40' N.; long. 58 33' W.; 

 880 fathoms; glob, oz.; temp. 38 F. One specimen. 



1 Ofv. K. Vet. Akad. Forh., vol. 28, p. 618. 



