94 



ECHINOIDEA. II. 



speciinen really canie from that locality. Fiirtlier, since tlie type speciineii of Wyv. Thomson was 

 taken at St. 45 (38' 34' N. 72° 10' W. 1240 fathoms)', and only two specimens are mentioned in tlie 

 «Cha!lenger -Report, one of wliicli (St. 191) is no true A. rostrata, it .seems not hazardous to suggest 

 that *Bay of Biscay and Coast of Portugal was wrongly named aniong tlie localities of A. rostrata. 

 Botli the localities named in the • Challenger -Report, p. 194, are tims wrong; on p. 220 the locality 

 Davis Strait is rightly named. 



A few remarks must be made on the pacific species, Acropsis fulva (A. Ag.) The structure of 

 tlie test has been very elaborately worked out by Professor Agassiz (Pan. Deep-Sea Ech. p. 194— 97, 

 PI. 61, 62), and the spines and pedicellariæ have been described and figured by de Meijere ( Siboga- 

 Ech. p. 195. Taf. XXIII. Fig. 481 — 87). Having examined some specimens from <:Albatross:. St. 3361 and 

 3399 in the U. S. National Museum I am able to give a little additional information. In the shape 

 of the tridentate pedicellariæ I do not find aiiy distinct difference from A. rostrata; I have seen none 

 with meshwork in the blade. The rostrate pedicellariæ (only one specimeii found) differ distiiictly from 

 those of ^[.rostrata (PL X\^ Fig. 34); the blade is shorter and broader than in that species and some- 

 what serrate at the lower end. — In the elongate specimen from the Challenger« St. 191 I find the 

 tridentate pedicellariæ somewhat different (PI. XV. Figs. 6, 12, 27). In the larger ones the edges in 

 the lower part of the blade are very irregular, somewhat thickened or thoriiy, and tliere may be a 

 rather well developed meshwork. The smaller ones have upon the whole shorter and broader 

 valves than is the case in A. fulva and rostrata, and there is ofteh some meshwork developed already 

 (PI. XV. Fig. 27, comp. with Fig. 29). These small differences, in addition to those pointed out by Pro- 

 fessor Agassiz (Pan. Deep-Sea Ech. p. 194), may perhaps tend to show that this specimen from the 

 v\rafura Sea represents a third species, different from A. Julva, though certainly iiearer related to that 

 species than to A. rostrata. Unfortunately the figures of pedicellariæ given by Dr. de Meijere are so 

 little detailed that it cannot with any certainty be concluded from them whether his specimens agree 

 in regard to the pedicellariæ with A. fulva or with the vCh.allenger >-specimen from the Arafura Sea- 

 This qnestion about a third species of Acropsis must be left undecided for the present; but the main 

 thing here was to show that the elongated form from the Arafura Sea is not A. rostrata, and this, I 

 think, has been put beyoiid doubt. 



Also 011 Aceste bellidfcra a few remarks must be made here. (I have e.xamiiied a specimen 

 from the iChallenger* St. 8 in the British Museum, and another from the ^^Albatross« St. 2117, which 

 Professor Rathbun most liberally lent me for exainination). First as regards the name Aceste, though 

 apparently so original, it is perhaps a little doubtful if it can be maintained, the name Accsta having 

 been used already in 1855 by Adams for a bivalve mollusc (Lima cxcavata). Still the ending of these 

 two names is really different so that I do not think it iiecessary to alter the name Aceste. (It might, 

 otherwise, easily be done sufficiently e. g. by adding only an s >, so that the name would be easily 

 recognizable). — Regarding the structure of the test I have nothing to add to the careful analysis 

 given thereof by Loven; especially the apical system is seen by Lo vén's Figure (Pourtalesia. PI. XX. 

 237) to differ considerably from what is seen in the Fig. 7. PI. XXXIII. a. of the vChallenger > Report. 



The pedicellariæ have partly been figured by Professor Agassiz, but not all sufficiently de- 



■ 'The AtiantiC". I. p. 381. 



