ECHINOIDEA. II. 8"^ 



distiiict calcareous cap in the point of the tube-feet (PI. VII. Fig. 17), thoiigh not foniied l)y one platc. 

 The spicules are of the n.sual form, lyin,<T in two clo.se longitudinal series. 



Echinocrcpis ciinrata A. Ag. In this species the bivial ambulacra are evidenth- nninterrupted 

 ( Chall. -Ech. PL XXXV. a. 10), as is also pointed ont by de Meijere ( Siboga -Ech. p. 168). In Pan. 

 Deep-Sea Ech. p. 147 Agassiz states that the arrangement of the actinal piates of Echinocrcpis 

 cuncata is, according to Loven (Pourtalesia. PI. VII. Fig. 53), much like that of Spatagocystis Clial- 

 lengcri .... which seenis to mean that the bivial ambulacra are interrupted by the interambulacra i 

 and 4. This can, however, not be deduced from the small fragment figured by Loven, and the figure 

 from the Chall. -Ech. quoted above does not seeni to be so very incorrect, as it would be, in case 

 the species really agreed with Spatagocystis in this respect. Also Loven states exjiressly (p. 17) that 

 he considers Ecliiiiocr. cuiirata to differ in a marked manner* from P. Jcffrcxsi. lagiDiciila etc. in 

 having the bivial ambulacra nninterrupted. LTnfortunateh' the specimen in the British JMuseum does 

 not afford any solution of the question, the plastron not being preserved. The aj^ical system ' is coni- 

 pact, the postero-lateral (bivial) ambulacra not being sejDarated from the rest of the apical s\stem 

 through intercalated piates, as has been shown b\- Loven (On Pourtalesia. PL VII. F'ig. 54); I may 

 further point out the faet that the dorsal piates of the odd interambulacrum are not paired, but alter- 

 nating (as seen in this same figure) evidenth- a more primitive condition. (jf pedicellariæ I have seen 

 only one kind, viz. tridentate. The small ones are of the common simple leafshaped form, with the 

 apophysis continuing into the ed ges of the blade; the larger form is figured in the Challenger -Re- 

 jjort PL XLV. Fig. 44, I have only to add that generalh' there is a wingshaped keel along the dorsal 

 side of the blade (PL X. Fig. 39). The spicules are rather numerous, simple or triradiate. 



Ecliiiiocrcpis sctigcra A. Ag. differs from E. ciiiicafa in several important features. The bivial 

 ambulacra are interrupted on the actinal side by the postero-lateral interambulacra, and the apical 

 system is disconnected. I have found three kinds of pedicellariæ (on some small fragments examined in 

 the U. S. National Museum), \iz. tridentate, rostrate and ophicephalous. The tridentate pedicellariæ are 

 of the common form, with simple leafshaped valves (only a small specimen seen). The rostrate pedi- 

 cellariæ (PL X. Fig. 12) are more or less elongate, the outer edge finely serrate. (Perhaps this form is 

 not reall}' the rostrate, but another kind of tridentate pedicellariæ.) The ophicephalous pedicellariæ 

 (Pl.X. Figs. 3, 33) are .somewhat smaller and more longstalked tlian usual; otherwise they do not differ 



1 Agassiz (Panainic Deep-vSea Ecli. p. 131) savs that «the piates of the apical system of EchinocvL'pis are not as they 

 have been described by de Meijere; those of the bivium are well separated by the posterior lateral interambulacra from 

 those of the trivium. There are the two posterior ocular piates, and the auterior ones are ankylosed, the oculars of the tri- 

 vium being lost and occupied by the madreporite. (Pis. 67. fig. 2; 69, figs. 3, 4) ». (Juite apart from the faet that Agassiz 

 here is in evident contradiction to his own statement (p. 146) that in Echinocrcpis setigera < the ocular plate can only be 

 traced in the odd anterior ambulacrum. In the crowding due to the intrusion of the intercalated and interambulacral piates 

 betweeu the bivium and the trivium they (— evidently the other ocular piates — ) have been pushed out of place or resorbed >, 

 it may be stated that de Meijere's description ( Siboga -Ech. p. 162) is quite correct, his description being based ou 

 Lovén's Figure 54. PI. VII lOn Pourtalesia), as expressly named, and it is Echinocrepis cuneaia whose apical sjstem is 

 described, as is also expressly said, not E. setigera, to w-hich Agassiz refers. Further de Meijere remarks (p. 1641 Nach 

 Agassiz' Figur (viz. PI. XIII. i of the Prelim. Report on the Albatross -Echini) scheint die von der .Albatross»-Expedition 

 erbeutete Echinocrepis seligera auch ein cbensolches, aus einander geriicktes Apicalsystem zu besitzen, wie Spatagocystis u. s. w. 

 und wurde sich somit von E. cuncata scharf unterscheiden -. De Meijere's description of the piates of Echinocrepis is thus 

 quite correct. 



