ECHINOIDEA. (IV, C.) 
Echin. 83 
Fourtau (92) : Cossmann states that Zittel makes Peronella Gray 
a syn. of Rumphia Desor, 1858, to which Fourtau replies that 
Peronella Gray has priority. 
Petalocidaris n. g. of Cidaridae , with genotype Goniocidaris Jlorigera ; 
Mortensen (229) pp. 29, 18: diagnosed; Meissner in Hamann (125) 
p. 1348. 
Pkormosoma, rediagnosed, comprising P. placenta , P. bursarium , P. 
rigidum ; Mortensen (229) p. 62: diagnosed; Meissner in Hamann 
(125) p. 1350. P. alternans n. sp., Malay Archipelago, 694 m, ; 
de Meijere (53) p. 2. P. asterias, pedicellariae (p. 46), redescr. from 
holotype, made genotype of Kamptosoma (p. 60), P. bursarium, 
diagnostic characters (p. 47), P. hoplacantha, refd. to Hygrosoma 
(p. 59), P. luculentum , pedicellariae (p. 46), refd. to Hygrosoma and 
pedicellariae descr. (p. 59, pis. xii, xiii), P. panamense , discussed 
(p. 48), P. petersi, distinguished from P. uranus (p. 58), redescr. and 
made genotype of Hygrosoma (p. 59) ; Mortensen (229). P. placenta ; 
Nichols (236) p. 259: pedicellariae (p. 46), longitudinal muscles 
(p. 47), inch P. sigsbei, radioles, podia, pedicellariae, internal muscles, 
and development of apical area descr. (p. 66, pis. iv, xi, xii, xiii), young 
3, 5, and 7 mm. diam., descr. (p. 173), P. rigidum, diagnostic 
characters of holotype, perhaps syn. of P. placenta (p. 48), P. tenue, 
pedicellariae (p. 46), redescr. and refd. to Ecliinosoma (p. 57), 
? Challenger stat. 272 is a Kamptosoma (p. 61) ; Mortensen (229). P. 
uranus ; Nichols (236) p. 259: notes on holotype, refd. to Ecliinosoma 
(p. 57), specimen from Challenger stat. 78 is quite indeterminable, 
specimen so named by Koehler is Pkormosoma (i.e. Hygrosoma) petersi 
(p. 58) ; Mortensen (229). 
Phrissocystis humilis n. sp., Malay Archipelago 462 m. ; de Meijere 
(53) p. 14. . : . 
Phyllacanthus [vide etiam sub Cidaris spp.], rediagnosed, inch Leiocidaris , 
compr. P. imperialis, and ? P. dubia and P. parvispina, : Mortensen 
(229) pp. 30, 18: diagnosed; Meissner in Hamann (125) p. 1349: 
Section A, with genotype Cidaris tribuloides Lam. s. str., is a simple 
syn. of Cidaris ; Section B. had genotype P. dubia, syn. of C. imperialis 
Lam. which is also genotype of Leiocidaris Des. a consequent syn. 
of Phyllacanthus', Lambert in Savin (283) p. 223. P. annuli- 
fera , referred to Stephanocidaris (p. 17), P. australis , probably not 
this genus (p. 28) ; Mortensen (229). P. baculosa , syn. of Leiocidaris 
pistillaris (q. v.); Doederlein (62). P. gigantea , genotype of Chon- 
drocidaris ; Mortensen (229) p. 20. P. imperialis, v. sub Leiocidaris. 
t Pkyllobrissus, diagnosis (p. 130), P. gresslyi and P. neocomiensis (p. 131), 
P. nicoleti, descr. (p, 132), P. renaudi , descr., discussed by Lambert 
(p. 133); Savin (283). 
\Phymechinus, diagnosis, P. lamberti n. sp., Mid. Valanginian, Col de 
J oigny, Savoy, types in Mus. Chamb^ry, and coll. Savin and Revil ; 
Savin (283) p. 116, ph i. 
Phymosoma, diagnosis; Savin (283) p. 168. P. crenulare, discussed, 
better called Glyptocidaris ; Mortensen (229) p. 130. f P. revili n. sp., 
Hauterivian, Les Combettes, Savoy, holotype in coll. Savin ; Savin 
(283) p. 169, ph ii. 
Phymosomatidae n. fam. = Phymosomiens Pomel ; Meissner in Hamann 
(125) p. 1359. 
\Platipygus [sic, melius Platypygus] n. g. of Cassidididae with genotype 
Cyrtoma postkumum Ortm., redescr. ; Loriol (200) p. 17, ph ii : vide 
etiam Lambert (177) pp. 479, 480, & Tournouer (310) p. 466. 
iPlegiocidaris, diagnosed as s.-g. of Cidaris ; Savin (283) p. 207 : P. 
cervicalis (p. 212), P. coronata (p. 211), P. cucumifera (p. 208), P. cf. 
delatourei (p. 217), P. elegans and P. filograna (p. 213), P. glandifera , 
