514 
ECHINODERMATA. 
haens). The genera Pygomma and Tetrapygus [Zool. Rec. ix. p. 444] are 
not recognized. A. cequituberculata (Mediterranean), pustulosa (Brazil), 
and loculata (Guinea), are united under one specific name. 
Ccdopleurus Jloridanus, id. (2), p. 8, pi. i. figs. 6-7. 
Echinus magellanicics, Phil., id. 1. c. p. 11, pi. iii. fig. 6 ; margaritaceus, 
Lam., id. ibid., pi. ii. fig. 6, pi. iii. fig. 4 (Juan Fernandez ? Cape das 
Bahias). 
Echinometra lucunter (L.) [?] and Colobocentr [o^] us atratus (L.) ; Hoff- 
mann (8), p. 51. 
Monophora darwini, Desor ; Agassiz (2), p. 12, pi. iii. figs. 1-3 (Tertiary). 
Some of Agassiz’s figures of PourtaUsia are copied, Z. Zool. ii. pi. ix., 
with a report on pts. 1 & 2 of the “ Revision ” (pp. 21G-221). 
Paloiopneustes cristatus^ Agassiz (2), p. 13, pi. iv. figs. 1-3. The repre- 
sentative in our days of Ananchytes, resembling it in outline and general 
appearance so far that it may, at first sight, readily pass for A. gibbosa 
[Zool. Rec. X. p. 600]. 
Nacospatangus gracilis j id. 1. c., p. 17, pi. ii. figs. 3-5 [Zool. Rec. 1. c.]. 
Lovenia cordiformis^ Ltk., id. 1. c. p. 19 (California). 
Agassizia excentrica, id. ibid. (Barbadoes, 100 fathoms, &c.). The 
young Spatangoid figured, pi. xiv. figs. 9-12, of the “ Revision,” is not 
the young of Agassizia, but of another unknown Spatangoid. 
Hemiaster philippii (Lov.), id. 1. c. p. 20, pi. figs. 4-8 (Patagonia). 
With increasing age and size, the ambulacra from shallow become deeply 
sunken, and change their form so much, that the range of the transforma- 
tion in this one species is far greater than distinctions, used as generic 
features among allied fossil Spatangoids. II. australis is therefore pos- 
sibly the young form of H. cavernosus. 
Tripylus excavatus^ Phil., ? (Young) id. 1. c. p. 52. 
Maretia (?) elliptica^ Bolau (4), p. 175, pi. vi. figs. 1 & 2 (Maldon Island, 
South Sea). 
Brissus sternahideSj id. 1. c. p. 177, pi. vi. fig. 3 (Bay of Siam). 
Dedhia, g. n., Pdvay (12), p. 148, “ differt a Brisso et Brissopsi, sulco 
frontali profundo, tuberculis maximis areolatis, et praecipue rostro 
postico saliente, a Plagionoto vertice excentrico, facie posteriori oblique 
truncata et rostrata, petalis anticis fere hofizontaliter distantibus, tuber- 
culis majoribus per fasciolam peripetalam antice non limitatis ; a 
Lovenia, fasciola interna deficiente.” [As to the instability of this genus, 
cf. Verh. geol. Reichsanst. 1875, p. 69.] For D. rotundata, ovata, and 
cor data, spp. nn., id. ibid. 
Special chapters are devoted to the geological succession of Echini,'* 
and to the Perischoechinidm, in. Agassiz’s “ Revision.” Etheridge (5) 
reviews the characters of the palaeozoic division, while Baily (3) 
corrects those of some of its genera. Bothriocidaris, Eichw., of which 
two species are described and figured by Schmidt (14), is the type of 
another principal division of palaeozoic Sea-Urchins, distinguished — in 
opposition to the “tessellate” division — by the shell being only composed 
of fifteen series of plates, 6 single series of interambulacral plates alter- 
nating with 5 double series of ambulacral plates. Each of these is pro- 
vided with a pit, which includes 2 pqres for the suckers, and has, on the 
