430 Proceedings of the Royal PJiy steal Soeicty. 



POURTALESIID^. 



14. Pourtalesia, Agassiz. 

 1869. Pourtalesia, Agassiz, Bull. Mus. Comp. ZooL, i. p. 272. 

 Test elongate bottle-shaped, thin and transparent ; mouth at 

 one extremity, terminal, in a deep groove ; anus supramarginal, 

 at the other ; posteriorly a process projecting beyond the anus; 

 smaller spines spatulate ; four genital openings ; ambulacral pores 

 extend as simple rows from apex to mouth. 



27. Pourtalesia miranda, Agassiz. 



1869. Pourtalesia miranda, Agassiz, Bull. Mus. Comp. Zool. , i., p. 272. 

 1872. ,, ,, Id., Eev. Ecliin., pp. 152, 345, 561, 



pi. xviii. 



Diagnosis. 



This species may be distinguished by the superior surface being 

 almost straight as seen from the side, the inferior gently convex ; 

 the oral notch is small and narrow. 



As above indicated, there is an uncertainty regarding the 

 occurrence of this species in the British area which I have not 

 the means of clearing up. Sir Wyville Thomson says, " Both of 

 the two specimens procured by Mr Gwyn Jeffreys at a depth of 

 1215 fathoms in the Bockall Channel are immature, and their 

 characters are too undefined for satisfactory description." Agassiz 

 ("Rev. Echin.," p. 152) quotes this locality and depth under the 

 habitat of P. miranda with a ( ! ), which signifies that he had 

 himself seen the specimens, and satisfied himself regarding their 

 identification. This would seem to indicate that Agassiz regarded 

 the types of P. phyale as referable to P. miranda. We find, 

 however, that in his " Challenger" Beport (p. 138) he still regards 

 P. phyale as a valid species, and devotes half a dozen figures to 

 its elucidation, whilst in his distribution table (p. 217) he quotes 

 this locality and depth both for P. iniranda and P. phyale. Is it 

 possible that of the two specimens one belonged to each species ? 



British Seas. — [Off Bockall, 1215 fms., Shetland ("Porcupine" 

 Exp.), /cZe Agassiz.] 



Other Localities. — Florida Gulf Stream, 349 fms. (Pourtales, 

 fide Agassiz, 2). East Coast of U.S.A., off Havana, 242-576 

 fms. (Agassiz, 5). 



28. Pourtalesia Jeffreysi, WyviUe Thomson. 

 1874. Pourtalesia Jeffreysi, Wyv. Thomson, "Porcupine" Echin., 



Phil. Trans., p. 747, pis. Ixx., Ixxi. 

 1883. ,, ,, Loven, Pourtalesia, pis. i.-v. ; pi. xii.,' 



liil. 149. 



