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OPHIOTHRIX LONGIPEDA. 



a band of blue ; below, disk pale blue, arms mottled and speckled with 

 dark and light blue ; arm-spines transparent, nearly white ; the points 

 of the larger ones brownish. 



Opliiotkrix Cheneyi stands near 0. longipeda, but has arms only 

 about half as long, and the upper arm-plates are oval, while in O. 

 longipeda they are cleanly angular and quite smooth. It is distia- 

 guished by its large size and its broad, flat arms, bearing regular and 

 well-marked upper arm-plates. 



An exammatiou of the original in the Berlin Zoological Museum 

 (No. 1000) has shown me that Miiller's 0. hirsuta stands much nearer 

 the present species than his description would indicate. This specimen 

 is in alcohol, and was brought from the Red Sea by Hemprich and 

 Ehrenberg. It has the large, puffy disk usual in 0. longipeda. Two 

 other specimens, dry (No. 1002), also from the Eed Sea, are likewise 

 labelled 0. hirsuta, and, according to my notes, agree well with 

 O. Cheneyi ; but are not clearly the same species as the original above 

 mentioned. The point must therefore stand in doubt till the speci- 

 mens can be compared side by side. In the Jardin des Plantes is an 

 Op)hiothrix which seems the same as the origuial of 0. hirsuta. It 

 has the same puffy disk, and was l^rought from the same locality by 

 Botta. 



LIST OF SPECIMENS. 



Ophiothrix longipeda Mull. & Trosch. 



Ophiura longipeda Lajik. Hist. Anim. s. Vert., 11. p. 544. 

 Ophiothrix longipeda Mull. & Tnoscii. Syst. Asteridon, p. 113. 



The original of Lamarck, in the Jardin des Plantes, is a dried 

 specimen from the He de France. The arms are eighteen times the 

 diameter of the disk. This species is a near relation of 0. hirsuta 

 and O. Cheneyi, with similar flat arms and horizontal spines. But 



