Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-04T13:05:28.827Z Has data issue: false hasContentIssue false

II.—Morphological Studies on the Echinoidea Holectypoida and their Allies

Published online by Cambridge University Press:  01 May 2009

Herbert L. Hawkins
Affiliation:
Lecturer in Geology, University College, Reading.

Extract

In the three preceding papers of this series descriptions have been given of the perignatliie girdles of familiar representatives of the three families into which the Holectypoida are at present divided. From the scanty evidence available, it would appear that in respect of this structure Plesiechinus is typical of the Pygasteridæ (even including Anorthopygus). The girtile of Holectypus seems essentially similar, thereby differing from that of the Discoidiinse; but as yet the perignathic structures of the Cretaceous Coenholectypus are unknown.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1918

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)