ECHINOIDEA. II. 



39 



to refer them all to the high form. Only in case all the ?species of v. Phelsum were beyond doubt 

 of the high form, would it be necessary to change the names Echinocyamus and Fibularia; but this 

 is so far from being the case that perhaps they all really belong to the flat form. Accordingly it 

 would not only be a very unfortunate thing to change the names Echinocyamus and Fibularia, but it 

 would even be wrong and contrary to the rules of priority to do so. It may be considered as certain 

 that Echinocyamus pusillus is among the species of van Phelsum, since some of his specimens 

 came from the Adriatic, and if Lambert is right - - as I think he is - - in regarding all the 14 

 speciess of Echinocyamus figured by van Phelsum as one species only, they are all Echinocyamus 

 pusillus. I agree that from the three last columns of the plates in van Ph els urn's old book and - 

 perhaps from some of the descriptions it might seem to be the high form which is represented; 

 but the two first columns in any case resemble much better the flat form, and above all the locali- 

 ties given by van Phelsum prove definitely that they cannot represent the high form, because only 

 tlat forms occur in the Adriatic and at America. It is then only the bad drawing which makes the 

 figures in the three last columns (sidewiew, endview and from below) look like the high form. But to 

 ascribe such importance to some evidently quite impossible figures as to found thereupon a most 

 unhappy change of names universally used, against the (in this case) quite certain deduction from the 

 localities, seems to me unjustifiable, and I must protest against such a proceeding with all my force. 



Suborder Meridosternata. 

 Fam. Urechinidae. 



19. Urechinus naresianus A. Ag. 



PI. VI. Figs. 10-11. H. VII. Figs. 6, S, 13, 15. PL IX. Figs. 4, 8^9, 15-16, 18, 21. 26. 29-39. 



A. Agassiz: Challenger -Echinoidea. p. 146. PI. XXIX. Figs. 14. PI. XXX. XXX a. Figs. 14. 

 PI. XXXIX. Figs. 29 30. PI. XL. Figs. 56 58. - < Blake >-Echinoidea. p. 52. PI. XXVI. 13. -- Panamic 

 Deep-Sea Echini, p. 156. PI. 58. 5. 60.45. 74.68. Loveu: On Pourtalesia. p. 90. PI. VIII. 56. PI. 

 XXI. -- Duncan: Revision of the genera of Echinoidea (132) p. 211 12. -- Bell: Echinoderma found 

 off the Coast of South Africa. I. Echinoidea. (Marine Investigations in South Africa. III. 1904.) p. 173. 



The structure of the test of this highly interesting Echinoid has been so well worked out by 

 Agassiz and Loven that very little can be added in this respect. I only wish to call attention to 

 the fact that the inner edge of the plates round the peristome is somewhat thickened (Fig. 3) as 

 pointed out for Cystechinus by Agassiz. (Comp. e. g. PI. 78. 5. Panamic Deep-Sea Ech.) The irregularity 

 in the specimen figured PI. VI. Fig. 10, the plate II. b. 3 having two pores, 4 none, is worth noticing, 

 though, of course, only an individual abnormality. 



The rich material from the ilngolf includes some young specimens, so that I am able to give 

 some information of the changes due to growth in this species. 



The youngest specimen taken by the Ingolf is 3 mra in length. Unfortunately it is impossible 

 to find out the relations of the apical system in this small specimen; on account of its extreme frag- 

 ility I have been nnable to remove the spines completely without destroying the test, and I have not 



