242 ECHINODERMATA—ECHINOIDEA 
depressed dorsally. 
infra-marginal. 
Conolampas, Neolampas, A. Ag. 
Eocene. Palacolampas, Bell. 
Family 3. Collyritidae. 
Apical system disconnected, either elongate or sub-compact. 

Fia. 390. 
Collyrites elliptica, Desm. Callovian; Mamers, Sarthe. 
Dorso- 
A, B, Test in profile and from above, 1/}. C, 
central system, enlarged. 
d’Orbigny. 
SUB-BRANCH III 
Amb petaloid for a variable distance ; pores of the petals 
differing in shape, conjugated, and continued beyond in simple series. 
stome slightly in front, or sometimes central. 
Widespread in Tertiary and Recent. 
Recent. 
Upper Cretaceous and Tertiary. 
Peri- 
Periproct transversely elliptical, 
Plesiolampas, Duncan and Sladen. 
(Dysasterinae, Gray.) 
Ambulacra similar ; 
bivium widely separated from the trivium ; 
floscelle absent. Jura to Recent. 
Collyrites, Desm. (Fig. 390). Test 
ovoid, tumid, more or less truncated 
posteriorly. dmb disjunct, the an- 
terior one sometimes in a slight 
groove. Width of the Amb increas- 
ing toward the ambitus ; pairs of pores 
in low primary plates. Périproct 
posterior, supra-marginal, placed in 
a groove. Apical system elongate, 
separated by numerous small plates 
belonging to the postero-lateral L4mb. 
Very abundant in the Middle and 
Upper Jura and Cretaceous. 
Dysaster, Ag. Differs from Colly- 
rites in details of the apical system, 
the basals not being separated by the 
antero-lateral radial plates. Upper 
Jura and Lower Cretaceous. 
Hyboclypeus, Agassiz. Jura. In 
fraclypeus, Gauthier. Upper Cre- 
taceous. Grasia, Mich. Jura. 
Metaporhinus, Mich. Test very tall, slightly longer than broad, sub-cordi- 

Fia. 391. ria aA 
Hyboclypeus gibberulus, Ag. 
D, Apical system, enlarged. 
form, projecting upwards anteriorly, grooved and oblique behind. 

Middle Jura; Soleure, Switzerland. 4, B, Dorsal and ventral views. C, Profile. 
Anterior 
ae 
