26Q Prof. P. M. Duncan on the Identity of the 



basal half of the primaries is much more extensive, the apical 

 spot on the primaries is very small, and there is no spot on 

 the costa near the apical angle of the secondaries. 



Dr. Staudinger's collection contains a single specimen of 

 this species, the only one we have yet seen. 



XXXI. — On the Identity of the Ophiuran Genera Ophiopleura, 

 Danielssen and Koren^ and Liitkenia, Duncan, with Notes 

 on the Species. By Prof. P. Martin Duncan, M.B. Lond., 

 F.R.S., &c. 



The remarkable Ophiurans collected at Discovery Bay by Mr. 

 Hart, naturalist on board H.M.S. ' Discovery,' were described 

 by me in the ' Annals ' for August 1878 ; and their structural 

 characteristics were so remarkable and different from those 

 of any genus with which I was acquainted, that it was 

 necessary to include the forms under a s}>ecies of a new genus, 

 Liitkenia. 



Of course all the available literature, relating to the northern 

 Ophiurans especially, was searched before the generic dia- 

 gnosis and title were decided upon ; and I was not aware that 

 any thing Lad been published relating to the subject later than 

 Marenzeller's report on the Coelenterata, Echinodermata, and 

 worms of the Austro-Hungarian North-pole expedition, 1877. 

 But a " Separat-Aftryk af Nyt Magazin for Naturvidens- 

 kaberne," Christiania, was published in 1877; and it relates 

 to the Echinodermata of the Norske Nordhavsexpedition, 

 written by Danielssen and Koren. 



It contains the description of an Ophiuran which was suf- 

 ficiently peculiar to be separated from all others in a new 

 genus, Ophiopleura. The single species is fortunately well 

 illustrated and has been called Ophiopleura horealis, Dan. & 

 K. The specimens came from 510-570 fathoms, temperature 

 l°-3 C, and not further north than 63° & N. lat. 



The form was so decidedly separable, that the Scandi- 

 navians made a new family for its reception ; and they consi- 

 der the irregular arrangement and shape of the teeth of para- 

 mount importance : — " Tsenderne i uregelmasssige Rsekker, 

 fladtrykte, tilspidsede." This is the essential characteristic 

 of Liitkenia, nobis. Again, their generic diagnosis corre- 

 sponds with that of the genus I had established, with an 

 exception which is somewhat remarkable. In the description 

 of the species much is made of the presence of ten " Eibber " 



