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THE 



PALJIONTOGRAPHICAL SOCIETY. 



INSTITUTED MDCCCXLVII. 



LONDON: 

MDCCCLXIV — MDCCCLXXXII. 



THE CRETACEOUS ECHINOIDEA. 



DIRECTIONS TO THE BINDER. 



The Monograph on the Cretaceous Echiaoidea will be found in the Volumes of the Palaeontographical 
Society for the years 1862, 1867, 1869, 1870, 1872, 1873, 1875, 1878, 1881, and 1882. 

Cancel the Title-pages affixed to the separate parts, and substitute the general Title-page provided in 
the Volume for the year 1882. 



ORDER OF BINDING AND DATES OF PUBLICATION. 



PAGES 


PLATES 


ISSUED IN VOL. 
rOB TEAB 


PUBLISHED 


Title-page, Contents, i — xviii 


I-III, IIIa, IV— VII, VIlA, VIII 


1882 


June, 1882 


1—64 


— 


1862 


August, 1864 


65—112 


IX, X 


1867 


June, 1868 


— 


XI 


1862 


August, 1864 


— 


XII— XXI, XXIa, XXIb 


1867 


June, 1868 


113—136 


XXII— XXIX, XXIXa, XXIXb 


1869 


January, 1870 


137—160 


XXX— XXXIX 


1870 


January, 1871 


161—184 


XL— XLIV 


1872 


October, 1872 


185—224 


XLV— LII 


1873 


February, 1874 


225—264 


LIII— LXII 


1875 


December, 1875 


265—300 


LXIIa, LXIIl— LXIX 


1878 


March, 1878 


301—324 


LXX-LXXV 


1881 


May, 1881 


325—371 


LXXVI— LXXX 


18S2 


June, 1882 



K^.^' 






monog:raph 



Yx I ON THE 



jtJU 



BRITISH FOSSIL 



ECHINODERMATA 



FROM 



THE CRETACEOUS FORMATIONS. 



THOMAS WRIGHT, M.D., F.R.S., F.G.S., 

VICE-PRESIDENT OP THE PAL«0NT0QRAPH1CA.L SOCIETY ; CORRESPONDING MEMBER OP THE ROYAL SOCIETY OF SCIENCES 

OF Ll:fiGE ; THE SOCIETY OF NATURAi SCIENCES OP NEUCHATEl,; VICE-PRESIDENT OF THE COTTESWOLD 

naturalists' FIELD CLUB; CONSULTING SURGEON TO THE CHELTENHAM HOSPITAL; 

AND MEDICAL OFFICER OF HEALTH TO THE URBAN SANITARY DISTRICTS 

OF CHELTENHAM, CHARLTON KINGS, AND LECKHAMPTON. 



VOLUME I.— THE ECHINOIDEA. 







LONDON: 
FEINTED FOK THE PALiEONTOGKAPHICAL SOCIETY. 

1864—1882. 



PEINTBD BY 
J. E. ADLARD, BAUTHOLOMEW CLOSE. 



CONTENTS. 



Preface .... 

Retrospect .... 

History of Echinology since 1862 

Bibliography of ditto 

Divisions of the Cretaceous Formation in England 

Classification of the Echinodermata 

Terminology of the Component Elements of the Test of the Echinoidea 

Classification of the Echinoidea, Endocyclica and Exocyclica 

Description of the Families, Genera and Species of the British Cretaceous 

Echinoidea ....... 35 — 342 

Summary of ditto ...... 345 — 359 

Range in Geological Time of ditto ..... 360 

Index ........ 361 — 371 



PAGE 

. i, ii 

. iii, iv 

iv — sii 

xiii — xviii 

1—14, 343, 344 

15—20 

21—28 

29—34 



PREFACE. 



With this Preface the history of the British Fossil Cretaceous Bchinoidea is 
brought to a close, and it only remains for the Author to record his warmest 
acknowledgments to the many kind friends, enumerated in the retrospect, who 
have generously assisted him in his long and laborious task. The duty imposed 
upon him by the Council of the PaliEontographical Society, occasioned by the 
untimely death of his distinguished colleague, Prof. Bdw. Forbes, F.R.S,, has 
been much lightened by their ready, willing, and friendly aid at all times. 

When the Plates for this Monograph had been nearly completed his accom- 
plished artist, Mr. Charles Bone, who had assisted him during so many years, like- 
wise passed away ; so that in writing this preface the Author is solemnly reminded 
of the mutability of all human undertakings, and desires to express his deep regret 
that one who had aided him for nearly thirty years by steady, continiious, and 
most accurate work, had not been spared to see the conclusion of his labours. 
The Author, therefore, embraces the present opportunity of recording his high 
appreciation of Mr. Bone's artistic drawings, which for beauty and accuracy in 
lithographic art have not been surpassed, whilst all essential details relating to the 
anatomical structure of the Echinoidea have been faithfully rendered throughout. 

The Author in an especial manner desires to return his warmest acknowledg- 
ment and very best thanks to his old friend the Rev. Professor Wiltshire, F.G.S., 
the indefatigable Secretary of the Palteontographical Society, for his unwearied 
attention to every part of his work as it passed in successive years through the 
press. The admirable summary of the British Cretaceous Echinoidea and 
copious index which he has kindly contributed to complete this volume, have added 
much to its value and general usefulness ; and he must further add that the liberal 



11 



PREFACE. 



supply of fine specimens from his rich collection of Chalk Echinoderms, in order 
to furnish the artist with the best possible specimens for the plates, has been of 
very great assistance in carrying out the work, and for which he now expresses 
his deep obligations, and records his lasting gratitude for all his most kind, 
generous, and friendly aid from first to last. 



4, St. Maegaeet's Teeeace, Cheltenham ; 
25th April, 1882. 



A RETROSPECT. 



Before bringing this Monograph to a termination I desire to state to my Readers 
(many of whom have joined our Society since the work was commenced), the circumstances 
under which I became the historian of the British Cretaceous Echinodermata, and 
the difficulties I experienced and had to overcome during the progress of its composi- 
tion, as they help to explain the apparent delay that has occurred and the length of time 
which has elapsed between the issue of the first and last part of the Monograph. 

When the History of the British Fossil Echinodermata was first proposed to the 
Council of the Palseontographical Society in 1851, by the late Professor Edward Eorbes, 
it was arranged that the description of the Cretaceous species was to be undertaken by 
him, and that of the Jurassic species by myself. Long, however, before the Jurassic 
portion was complete my highly esteemed and learned colleague died (in November, 
1854), very soon after he had attained the object of his life's ambition, the Chair of Natural 
History in the University of Edinburgh. Before leaving London, Professor Eorbes had 
gathered from various sources a large collection of materials for the Cretaceous Mono- 
graph ; these he took with him to Edinburgh, intending to commence the work as soon as 
he had settled down into the routine duties of his new chair ; but his sudden death 
unfortunately deprived science of the rich store of facts and notes on the specimens he 
had collected from various cabinets for this work. Under these painful circumstances 
the Council of the Palseontographical Society urged me to undertake the description of 
the Cretaceous forms as soon as I had finished the Jurassic species ; and this I consented 
to do in the belief that the materials collected by Professor Eorbes would be available for 
the work. On making inquiry, however, I found to my dismay that after the death of 
my friend the fossils had been packed up with other property and sent into the cellars 
of the University, and could not be touched until some legal matters were arranged. A 
long delay now took place ; and at last, when a search was made, the cases containing 
the Cretaceous specimens of Echinides could not be found. In this dilemma, and not 
then having a good collection of Chalk Urchins myself (all my energies up to that time 
having been given to complete my Jurassic collection), I applied to the authorities of 
the British Museum, to the Director of the Museum of Practical Geology (the late Sir 
Roderick Murchison) ; and to the Earl of Ducie, the Rev. Thos. Wiltshire, the late Dr. 
Bowerbank, the late Professor Tennant, the late Dr. S. Woodward, Mr. W. Cunnington, 

b 



iv BRITISH FOSSIL ECHINODERMATA. 

Major Cockburn, Mr. Caleb Evans, Mr. Robert Etlieridge, and Mr. Weist. Messrs. E. T. 
Newton and Sharman, Assistant Naturalists of the Jerrayn Street Museum, most kindly at 
all times aided me in making selections of specimens for figuring in the plates. 

On the Continent I have had much friendly aid from MM. Gustave Cotteau, of 
Auxerre, Perceval de Loriol, of Geneva, Herr Struckmann, of Hanover, Professor De 
Koninck, of Liege, and the late MM. Seemann and Triger, of Paris. 

In addition to the valuable aid of the above kind friends, to vi^hom individually and 
collectively I tender my warmest thanks, I have made many tours of inspection to all 
the best private collections in England containing Chalk Echinoderms, and have visited 
and worked the quarries in the different Cretaceous formations, in order to identify the 
distribution of the species with the beds from whence they were said to have been 
collected. All these proceedings have occupied much time, and were undertaken at a 
period when I was fully occupied in the laborious practice of my profession, so that I found 
much difficulty in bringing out the parts consecutively in the annual volumes of the 
Palseontographical Society. 

The many duties and incessant occupation connected with my present position as 
Medical Officer of Health having deprived me of the leisure necessary to continue my 
sketch of the History of Echinology, I ventured to ask my much esteemed friend, M. 
Perceval de Loriol (author of the ' Echinologie Helvetique ')j to undertake this portion of 
the work. Monsieur de Loriol, with his usual kindness, consented to do so, I have, 
therefore, now the pleasure of introducing his masterly sketch (for the translation of 
which I alone am responsible) of the progress made in Echinology during the last twenty 
years. For this most valuable addition to my work I beg to return my highly accom- 
plished friend my very warmest thanks. 



" On the History of Echinology since 1863, by Perceval de Loriol. 

The fourth part of the vast Monograph, undertaken by Dr. Wright, relating to the 
description of the Jurassic Echinides, was published in 1861. Dr. Wright had enriched 
that part with a Table, giving a list of the works concerning the Echiuides, that had 
come to his knowledge up to that date. It will not be without interest and utility, 
therefore, to terminate the Monograph on the Cretaceous Echinides, to which Dr. Wright 
is now adding the last pages, with a rapid review of the progress which has been accom- 
plished during the last twenty years in the domain of Echinology, and to take a glance at 
the magnificent discoveries for which we are indebted to the late Expeditions, which 
had for their object the investigations of the depths of the sea. 



A RETROSPECT. v 

Dr. Wright's numerous professional occupations not permitting him to enter upon 
this branch of the subject, he has asked me to take it upon myself, and it is with very 
great pleasure that I embrace the occasion of co-operating, in however feeble a degree, 
in a great and beautiful work, brought so happily to a conclusion by my learned 
friend. 

Commencing with an enumeration of the many works written on the Fossil Echinides, 
I think we shall proceed with more method if they be grouped by countries and by 
regions, taking into consideration, not the nationality of the authors, but the Echinitic 
fauna upon which they have made their observations.^ 

The study of the Eossil Echinides of Great Britain appears during late years to be 
concentrated in the general Monograph by Dr. Wright, and I find myself able to cite 
only one paper, that by Mr. Keeping (1), ' On the Genus Pelanechinus, a new Section 
established for the Hemipedina coraUina, Wright,' the coronal plates of which appear to 
have been in some measure imbricated, resembling those in Asihenosoma. 

France has contributed a great number of works on Echinology, of which most are 
due to the indefatigable zeal and untiring industry of M. Gustave Cotteau, of Auxerre ; 
and it is important to mention above all a work of the first order, the 'Echinides 
de la Paleontologie Fran^aise' (2), the publication of which is still being actively 
carried on. 

The ' Elchinides Cretaces,' commenced by d'Orbigny and continued by M. Cotteau, is 
now completed. Two volumes of the 'Echinides Jurassiques ' have already appeared. 
They comprise the Echinides irregxdiers, the family of the CidariDjE, and those of the 
Saleniad^ ; those of the DiadematidjE will soon follow. Three other very important 
works of M. Cotteau, commenced many years ago, have been completed ; the description 
of the Echinides of the Department of the Sarthe (3), in which he has made known the 
Urchins, so numerous and varied, which the Jurassic and Cretaceous strata of this 
Department contain, and the illustrations of which required sixty-five plates ; the second 
part of the ' Echinides of the Yonne ' (4), comprising the description and figures of ninety- 
nine species from the Terrains Cretaces ; and lastly the first series of new or little known 
Echinides, which have successively appeared in the ' Revue et Magasin de Zdologie ' (5), 
and in which are found valuable observations upon known species, as well as the 
description of numerous new species, the most part derived from France, but also 
from other countries. Independently of these works, as a whole, M. Cotteau has 
published many local Monographs, which have made great steps towards an exact know- 

1 To avoid the incumbrance of notes I shall add an appendix to this essay, in which I shall give the 
titles of the works to be identified by corresponding figures in the text. I have not cited all the works in 
which Fossil Echinides are mentioned, but only those which appear to me more specially important either 
as general works on the subject, or those in which some discovery is recorded. To this end I have made as 
conscientious an investigation of all the works as was in my power ; but possibly some publications may 
have escaped my notice. If such should be the case I make an honorable amende in advance for the 
omission which I shall be the first to regret. 



vi BRITISH FOSSIL ECHINODERMATA. 

ledge of the Ecbinitic Fauna of France. These contributions are in the form of 
notes, or lists of species, with observations made to clear up critical questions, with 
sometimes more complete studies on which the species are found entirely described and 
figured. M. Cotteau has thus made known successively the Nummulitic Echinides of 
Biarritz (6) ; the Cretaceous Urchins of Martigues (7) ; the Echinides of the Pyrenees 
(8) ; those of the Aube (9) ; and those of the Oxfordian of the Ard^che (10) ; new species 
from the Environs of Bordeaux (11); the Echinides of the Cretaceous Colony of the 
" Garonnien" of the Department of Aude (12), among which was found the first Cretaceous 
ScJdzaster known; those of the Miocene deposits of Corsica (13) ; those of the Jurassic 
strata of Normandy (14) ; and lastly, a supplementary note (15) completes the character- 
istics of the curious new genus Tetracidaris, from the Neocomian of Central France, 
which possesses two series of pairs of pores in each poriferous zone, and four 
series of inter-amubulacral plates. In addition to these beautiful monographic studies 
of M. Cotteau, there are other works upon the Echinides of France, which still remain 
to be enumerated. Thus, Saemann and Dollfuss, in 1861, characterised with care 
some species from Trouville (16). Dumortier, in his remarkable work upon the ' Depots 
Jurassiques du Bassin du Rhone,' has described many Echinides from the Lias (17). 
M. Tournouer (18), has given a revision of the Echinides of the Calcaire a Asteries 
(Tongrian) of the South-west of France, with figures of new species and critical remarks 
on the same. Caffin (19) has occupied himself with the Echinides of the Environs of 
Evreux. M. Bucaille (20) has given a Catalogue Raissonne of those of the Seine Inf6- 
rieure, with descriptions of new species. Professor Hebert (21) has endeavoured accu- 
rately to diagnose the characters of certain Hemiasters, and he has (22) described two 
new Hemipneustes from the Chalk of the Pyrenees. M. Sauvage (23) has made known 
new species from the Upper Jurassic of the Boulonnais. M. Arnaud (24) has endea- 
voured to facilitate the determination of the numerous Cretaceous species of the genus 
Ci/phosoriia, to which he has added some new forms. Desmoulins (25), to whom 
Echinology was already indebted for numerous works, has made some interesting obser- 
vations upon six species of Ecliinolampas, upon the spines of Echinocidaris, and upon a 
Miocene Spatangus from Saucats. Finally, I have published (26) a description of some 
Echinides from Berrias and Aizy (27), and have been occupied with those from the 
Portlandian of the Yonne (28), also with those from the Upper Jurassic of the Bou- 
lonnais (29), and of the Haute Marne (30). A general work, by Dujardin and Hupe, 
upon the Echinoderms (31) has likewise to be mentioned. 

In Switzerland the Echinologic studies, to which Agassiz and Desor had already 
given such vigorous impulsion, have been continued. Etallon (32), who had already 
studied the Echinides from diff'erent formations bordering on the frontiers of France (33 
and 34) and of Switzerland, aided in the enlargement of a posthumous work of 
Thurmann's, 'LeLethsea Bruntrutana ' (35), in which numerous species of Echinides are 
found described and figured. M. Ooster (36) a few years afterwards published his 



A RETROSPECT. vii 

* Synopsis of Fossil Echinoderms of the Swiss Alps,' in which numerous species from the 
Nummulitic formation are found figured. He has given also indications of certain Alpine 
species in his ' Protozoa Helvetica' (37). I have described also some Echiuides from the 
Neocomian of Mont Saleve (39), from the Valangian of Arzier (40), and the Urgonian 
of Landeron (41). I have also undertaken, under the title of ' Echinologie Helvetique ' 
(42), the publication of the Fossil Urchins of Switzerland. In the First Part compre- 
hending the Jurassic Echinides I had the happiness of having for my collaborator 
M. Desor. I afterwards finished alone the Second and Third Parts, which treat 
of the Cretaceous and Tertiary Echinides. Four hundred and thirty-eight species 
are the contingent of the Echinitic fauna furnished up to the present time by the Secondary 
and Tertiary formations of Switzerland. 

Thanks to M. Cotteau, the Fossil Echinides of Belgium, hitherto known in a very 
summary manner, have been submitted to a new and very necessary revision. He has 
published, in succession, a ' Note on the Cretaceous Echinides of Hainaut ' (43), with some 
species figured ; the ' Description of the Echinides of the Calcaire Grossier ' of Mons, 
Senonian (44) ; and the ' Description of the Tertiary Echinides of Belgium ' (45), an 
important Monograph, in which thirty-one species are found figured and described, and of 
which thirteen species only were previously known, and the most of these very imperfectly. 

It is likewise to M. Cotteau that we owe the knowledge of three interesting species 
from the Upper Chalk of Sweden (46). 

Among the works which have appeared on the Echinides of Germany it behoves me 
to cite, in the first place, the volume on the ' History of Fossils of Germany,' which 
Professor Quenstedt has devoted to the Echiuides (47). The Atlas of twenty-eight 
plates contains no less than 1700 figures, with numerous magnified views; whilst the 
text treats of not only the Echinides of Germany, but also many others which are 
not found there. This work, the result of very considerable labour, comprehends 
a great number of useful indications and previous observations ; but it is to be regretted 
that Professor Quenstedt persists in his refusal to accept the nomenclature adopted in 
the naean time by all authors and corresponding to the actual state of our knowledge. 
The want of method and the improper denominations occasion much confusion, so that 
the practical utility of the work is much diminished, " Die Echiniden '' has, nevertheless, 
a real value, and has advanced science principally in making known several details of the 
structure of many species which had not been previously observed, and in many cases it 
will be consulted with advantage. The Chalk of the North of Germany has furnished to 
M. Schliiter (48) many new^ species which he has described and figured. Subsequently 
he indicated some others, but only gave short diagnoses of them (49). Besides, 
many of the Cretaceous species from the same region have been well figured and 
described by Schlcenbach (50) ; and M. Dames has given a description of the Jurassic 
species collected in the North-west of Germany. The Echinides of the Upper Creta- 
.ceous strata of the Valley of the Elbe have been described and figured by Prof. 



viii BRITISH FOSSIL ECHINODERMATA. 

Geinitz (52) ; and M. Schafliautl has given figures of the Tertiary species from Kres- 
senbertT, but in general they have not been determined in a correct manner. It is 
important moreover to cite the new 'Handbuch der Palseontologie ' by Prof. Zittel (54), 
and especially the well-written chapter treating of Echinoderms. 

For the Empire of Austria I have equally many Echinologic works to mention. M. 
Cotteau (55) has made known the Echinides of Stramberg, derived from the strata about 
which so much controversy has taken place. M. Laube has decribed those from the 
Bathonian stage at Balin (56), and those from the Upper Tertiaries of Austro-Hungary ; 
and he has discovered in the Eocene of the Mattsee (5S) a new genus, the Oolasfer 
bordering on \Anancliytes. The ]\Iiocene strata of Ottnang have furnished to Herr E.. 
Hoerness (59) some species ; and from those of the environs of Felmenes some others 
have been noted by Herr Loczy (60), amongst others a new and interesting EcJdno- 
cardium. 

The Urchins from the Eocene deposits of Hungary and Transylvania have been 
studied by Herr Pavay (61), who had undertaken a general Monograph on the Echinides 
of Hungary (62), of which his premature death only permitted him to give a first part to 
the world. 

The Cretaceous strata, but especially the Tertiary beds, of Istria and of Friuli (64) 
have furnished many Echinides to M. Taramelli. His summary descriptions have been 
completed by M. Bittner (65), who has also enriched the Tertiary fauna of Istro-Dalmatia 
with new and interesting species. 

The Tertiary strata of a region bordering upon Lombardy have been for a long time 
celebrated for their richness in Echinides, but a monographic study has not yet been 
made of them. Herr Schauroth (66), in his Catalogue of the Museum of Coburg, has 
made known in a very imperfect manner some new species. Herr Laube (67) has 
much augmented the number of forms, and grouping the whole of the known 
species, has endeavoured to establish a parallelism amongst the beds in which they 
are found. Herr Dames (68), following up these observations in a very extended 
memoir, has revised certain of Herr Laube's species, added new ones to the list, and 
established two new interesting groups : — the genus llarionia, which approaches 
Pygorhynchis, but possesses a pentagonal periostome ; afterwards the curious genus 
Ovidypem, which approaches very near to Conodypeus, and like it, was provided with a 
masticatory apparatus. It behoves us still to cite a fossil species of the genus Palao- 
pneustes recently discovered in the Seas of the Antilles. The Tertiary beds of the 
Vicentin seem to be almost inexhaustible, for Herr Bittner (65), following up the pre- 
cited memoir with another, has been able to add many more species, among which he 
has discovered several new forms that were unknown to his predecessors. 

The Miocene Mollusca of Italy have yielded to M. Manzoni (69, 70) many interesting 
Echinides ; and in the Middle Miocene he has collected a large and curious species of 
SpatangldcE (71, 72). M. Gemellaro (73) has described some species from the Upper 



A RETROSPECT. ix 

■Sequanian of Sicily ; and the Abbe Stoppani (74) has described some species from the 
Lower Lias of Lombardy. 

Regarding the Echinides of Spain I have only a few remarks to make. There are 
two works by M. Cotteau, one very short, relative to some new Echinides collected in 
Spain by M. de Verneuil (75), and the other being a contribution to a memoir of M. 
Barrois upon tbe Cretaceous strata of the Province of Oviedo, giving a description of 
some new Echinides from the Urgonian (76). 

The Echiiiitic fauna from the Miocene beds of the Island of Malta, which is very rich 
in fossil Urchins in a fine state of preservation, had been previously studied and reported 
upon by Dr. Wright (77). These fossils were subsequently the subject of a second 
raemoii', in which are additional notes, and the description and figures of some new 
species. In the Island of Melos a very interesting little Echinitic fauna has been 
found, apparently of Pliocene age, and in which Herr Dames has discovered a Cidaris, 
very different from those which now live in the Mediterranean (78). 

Before terminating my remarks relating to Europe I have still to mention a little 
work which I have made on the Tertiary and Cretaceous Echinides brought from the 
Crimea, by M. Ernest Favre (79). 

Crossing now the Mediterranean to pass into Africa we arrive in Algeria, which 
appears to be the promised land to the Echinologist, for in almost all the geological 
formations of this region the Echinides abound in a surprising manner. M. Coquand 
(80), in his ' Palasontology of the Province of Constantine,' first made known a great 
number of species. Afterwards came the large and beautiful publication of MM. Cotteau, 
Peron, and Gauthier (81), which, commencing with the Jurassic strata, undertakes to 
describe all the Eossil Echinides of Algiers ; this work has now reached the Senonian 
stage of the Cretaceous deposits. Among the numerous species which these rocks 
have yielded, the number of those appertaining to the genus Hemiaster is truly extra- 
ordinary. In a recent work by M. Coquand (82), a great number of additional species 
of the same genus are described, but unfortunately not figured, hence it is impossible 
to give an exact account of the value of their characters. 

I am of opinion that a general revision of the species woidd result in diminishing the 
number, for I cannot but suspect that sufficient allowance has not been made for sexual 
differences, which are important, and which have been studied in Hemiaster cavernosus 
living in the Seas of Kergueleu, by Sir Wyville Thomson (' Challenger, Atlantic,' vol. ii, 
p. 229), and by Dr. Theoph. Studer (" Ueber Geschlechts Dimorphismus bei Echino- 
dermen," 'Zool. Anzeiger,' Nos. 67 and 68, 1880). The beds in the North of Africa 
are certainly far from being exhausted, and the Tertiary strata yet unexplored doubtless 
contain many Echinides which by-and-by will become known. Mr. Etheridge has 
described a new Scutelloid genus obtained from the Miocene of Morocco (83), the genus 
Botuloidea. The Tertiary deposits of Egypt contain numerous species of Echinides, of 
which some only have been described, and for the most part very imperfectly ; they have 



X BRITISH FOSSIL ECHINODERMATA. 

been studied more completely of late years. Prof. Fraas has given an account of 
many Nummulitic species (84), and has discovered the large Clypeaster of the Pyramids 
{Clypeaster jEgyptiacus,^x\^'C), from a Miocene rock. I have since published a ' Mono- 
graph of the Nummulitic Echinides of Egypt ' (85), in which forty-four species are figured 
and described, and in another Monograph (86) the Eocene Echinides of Egypt and of 
Lybia, brought by Professor Zittel from his voyage of discovery with Dr. Rohlfs, 
the new species are added by me to that interesting Echinitic fauna. I may remark 
en passant that I have given in these monogi'aphs figures of the masticating apparatus of 
Conoclypeiis conoidens which Dr. Zittel had already discovered. This genus ought, 
therefore, to be removed from the family of the Cassidulid^Ej in which it has hitherto 
been classed. 

Our knowledge of the fossil Echinides of Asia is not yet very extensive. Since 
the ' Monograph on the Nummulitic Beds of India,' by MM. d'Archiac and J. Haime, 
the only extended memoir which has been published on the subject, to my know- 
ledge at least, is that of M. Stolitzka (87), on the ' Echinoderms of the Cretaceous 
Formations of India,' in which thirty-eight species are figured and described. Some 
isolated documents may still be noticed. Prof. Duncan has enumerated eleven Creta- 
ceous species collected in the South-east of Arabia, and at Bagh on the Nerbudda 
(88). He has likewise given indications of the Cretaceous Echinides of Sinai (89). 
M. Cotteau, in a notice on the Echinides collected in Syria by M. L. Lartet, has 
described some new species. Prof. Fraas (91), in his recent travels in Lebanon, has 
satisfactorily proved that the spines so long known under the name of Cidaris c/landifera, 
and believed to be identical with those from the Sequanian stage are, on the contrary, 
distinct, and are found in Cenomanian beds. M. Fuchs, lastly, has made known some 
Echinides from the Miocene beds of Persia (92). 

In the Island of Borneo Nummulitic beds are found containing Echinides, of which 
M. Fritsch has described some, establishing the genus Verheekia, still very imperfectly 
characterised (93). 

Thanks to Professor Zittel we know some Echinides from the Tertiary strata of New 
Zealand (94). 

Many recent works, have had for their object the Echinides from the Tertiary strata 
of Australia ; whence new species have been described by M. Laube (95), Mr. Etheridge 
(96), and Prof. Duncan (97), who has given a list of the species from the Tertiary 
strata of Australia actually known. They are to the number of twenty-four, and 
embrace two new genera, Paradoxechinus, Laube, and Meyalaster, Duncan. 

It now remains for us to cross the Pacific to California, where we shall have to 
remark upon some very curious Miocene and Pliocene species of Echinides, discovered 
by Mr. Remond (98), and figured anew by Dr. Gabb (99). Some new species are still 
to be indicated from the Eocene of South Carolina, by M. Conrad. Beyond this I have 
only been able to discover a few isolated notices upon the Secondary and Tertiary 



A RETROSPECT. xi 

Ecliiiiides of the United States in the works published during tlie last twenty years. Oa 
the other hand, assisted by the activity of my learned friend M. Cotteau, whose name 
I have had to mention in connection with the Echinitic faunas of almost every region, 
the fossil Echinides of the Antilles are now very well known. Mr. Guppy had already 
published nine new species from the Tertiary formations of the Island of Anguilla. M. 
Cotteau (102) has added as many as twenty-six Eocene and Miocene forms. He has 
made known the magnificent species of the genus Asterostoma (103), of which we had 
known only up to the present the single individual type, coming from the Tertiary strata 
of the Island of Cuba, where it is accompanied with some other species, which will 
be figured afterwards. 

In South America the Echinitic works within my knowledge are the isolated 
descriptions of some new species. Philippi (104) has described some from Bolivia; 
Herr Steinraann (105) has just added two others ; and I have described one from 
Ecuador (106). 

To this rapid expose of the progress of our knowledge of the fossil Echinides 
during the last twenty years, it will not be out of place to add a few words on the 
recent discoveries which have been made among living Echinides in the existing seas. 
It does not, however, appear necessary to enter into much detail or to do more than 
mention the published works. The magnificent and excellent work of Alexander 
Agassiz (107), 'Revision of the Echini,' published between 1872 and 1874, faithfully 
resumes all the works anterior to it, and, so to speak, fixes our ideas upon the species of 
Echinides known up to this time in our seas. It will always serve as a point de depart 
for all future works. The number of distinct species which are there found estab- 
lished and described amounts to 206. Since then the number has been considerably 
augmented, but always and almost solely by the recent Expeditions undertaken for the 
exploration of the bed of the sea, aided by dredges and appropriate machinery placed at 
the command of the explorers. Most of the new types which have been discovered 
belong to the most extraordinary forms ; and some of these represent genera found 
hitherto only in a fossil state, connecting in a very remarkable manner the existing fauna 
with that of former times. Already in the Dredging Expedition of the " Porcupine," 
Wyville Thomson had observed in the living state and made known in a complete 
manner t\ie Asthenoso7na (109), those regular Urchins so curious with a flexible test com- 
posed of imbricated plates, reminding us of certain Palaeozoic genera and belonging to 
a family, the EchinothuriDvE, represented up to the present time by some fragments 
found in the Upper Chalk and a single example of a recent species from an uncertain 
province. We know actually that it was one of two species all living in depths from 
10 to 2,750 fathoms, but principally in the greatest depths. The appearance of the first 
species oi Pourtalesia, dredged by Francois de Pourtales in the latitude of the Antilles, 
had astonished all the Echinologists. Tins extraordinary genus, bordering on the 
Holaster and almost on the In/ulaster, approached more particularly the Urchins of the 



xii BRITISH FOSSIL ECHINODERMATA. 

White Chalk. We have lately discovered that there are several species, most of them 
bizarres forms ; and the Expedition of the " Cliallenger " has made known many new 
genera, which are connected with it, so that now this species, known at first by a single 
example, has become the 2^oint de depart, a few years after its discovery, of a family 
which appears to be truly limited to great depths. These two examples will suffice 
perhaps to make us appreciate the development of our knowledge of the Echinides of 
the actual seas during the last eight years. 

I do not intend to enlarge here upon the new species and the new genera which have 
been successively brought to light by the dredging expeditions of the " Porcupine," of 
the "Easier" (110), of the " Josephine," of the "Blake" (HI), of the " Challenger" 
(112). This last, which perhaps may be considered the most fruitful, has brought to our 
knowledge no less than forty-four new species and sixteen new genera. We are able to 
estimate roundly at 300 the number of the species which we know in our actual 
seas, and it is not only the discovery of new types which we owe to these expeditions, 
so rich in results of all kinds, but numerous and valuable indications and informa- 
tion on the geographical distribution of species, and on their vast bathymetrical limits, 
which are of the greatest utility in explaining certain facts relative to the distribution 
of fossil species, a subject upon which, perhaps, we may have experienced embarrassment. 
Now that we know that the Sjxifangus Basin is found from the Hebrides to the Cape of 
Good Hope, that the Brissojjsis lyrifera and the Schizaster fragUis are met with both in 
the seas of Norway and in the south of the Indian Ocean, and that certain species of 
Cidaris descend from the shore to 2000 fathoms, and that a Phormosoma descends from 
200 to 2700 fathoms, many facts relating to fossil Echinides will perhaps be able to find 
an interpretation. 

This is not the place to recapitulate the progress of the state of our knowledge upon 
the Morphology, the Anatomy, and the Embryogeny of the Echinides ; moreover, I am 
not competent to imdertake the work. 

I desire only to mention a remarkable w^ork by M. Loven (113), ' fitudes 
sur les Echinides,' accompanied by fifty-three excellent plates which contain very 
curious and most interesting researches on the structure of the solid skeleton of Urchins, 
and on the different points in their organisation. This useful work ought to be studied 
by all those who wish to make the Echinides the object of serious research. 

My task is now brought to a termination. I hope that those who, in the next 
twenty years, undertake a similar work will be able to register as many new facts, as 
many new discoveries, and as much progress of all kinds in the study of this very 
interesting group of animals, of which T have endeavoured to give a resume in the fol- 
lowing summary Table, which is probably less complete than I wished it to be. 



A RETROSPECT. xiii 

Appendix containing a List of the Works referred to in the Text. See 

Page v. 

1. Walter Keeping, 1878. On Pelanechinus (Quart. Journ. Geol. Soc, vol. xxxiv), 

2. Cotteau. Paleoiitologie frangaise (llchinides, T. 9, Terrain cretace ; T. 9 et 10, 

Terrain jurassique). 

3. Ecliinides du Departement de la Sarthe, 1855 — 69. 

4. Cotteau, 1857, 1878. Etudes sur les fichinides (Fossiles du Dep. de PYonne, 

T. 2, Terrain cretace). 

5. Cotteau, 1858 — 80. Echinides nouveaux ou peu connus, le Serie (Extrait de 

Revue et Magasin de Zoologie). 

6. Cotteau, 1863. Note sur les £clunides nummulitiques de Biarritz (Bull. Soc. 

Geol. de France, 2e Serie, T. 21). 

7. Cotteau, 1865. Notes sur les Oursins cretaces des Martigues (Bull. Soc. Geol. de 

France, 2e Serie, T. 21). 

8. Cotteau, 1863. Ecliinides fossiles des Pyrenees (Extrait du Congres Scientifique 

de France, 28e Session, T. 3). 

9. Cotteau, 1865. Catalogue raisonne des Echinides fossiles du Dep. de I'Aube 

(Extrait du Congres Scientifique de France, 31e Session). 

10. Cotteau, 1871, in Dumortier. Sur quelques giseraents de I'Oxfordien inferieur de 

I'Ardeclie, Description du Echinides. 

11. Cotteau, 1869. Descr. de quelques Echinides Tertiaires des environs de Bordeaux 

(Actes de la Soc. Linneenne de Bordeaux, T. 27). 

12. Cotteau, 1877. Descr. des Echinides de la Colonic du Garumnien de la Haute 

Garonne (Annales des Sciences Geologiques, T. 9). 

13. Cotteau, 1877. Description des Echinides Tertiaires de la Corse, in Descr. de la 

Faune des Terrains Tertiaires Moyens de la Corse, par A. Locard. 

14. Cotteau, 1877. Catalogue des Echinides jurassiques de Normandie (avec 2 plan- 

ches), Memoires de la Soc. geologique de Normandie. 

15. Cotteau, 1873. Sur le genre Tetracidaris (Bull. Soc. Geol. de France, 3e Serie, 

T. 1). 

16. S^MANN et DoLLFUSs, 1861. Etudes critiques sur les Echinodermes fossiles du 

Coral-rag de Trouville (Bull. Soc. Geol. de France, 2e Serie, T. 19). 

17. Dumortier, 1864-1872. Etudes paleontologiques sur les depots jurassiques de 

bassin du Rhone. 

18. TouRNOUER, 1870. Recensement des Echinodermes du Calcaire a Asteries du 

S.-O. de la France (Actes de la Soc. Linneenne de Bordeaux, T. 27). 

19. Caffin, 1807. Echinides des environs d'Evreux (Bulletin de la Societe des Amis 

des Sciences Naturelles de Rouen). 

20. BucAiLLE, 1872. Echinides fossiles du Dep. de la Seine inferieure. 



xiv BRITISH rOSSIL ECHINODERMATA. 

21. Hebert, ]S65. Etude d'un groupe d'Hemiaster (Bull. Soc. Geolog. de France, 

2e Serie, T. 22). 

22. Hebert, 1875. Descr. de deux Hemipneustes de la Craie sup. des Pyrenees (Bull. 

Soc. Geol. de France, 3e Serie, T. 3). 

23. Satjvage, 1872. Note sur quelques Echinoderiues des etages superienrs format. 

Jurass. de Boulogne-sur-Mer (Bulletin. Soc. geol. de France, 3e Serie, T. 1). 

24. Arnaud, 1877. Etude sur le genre Cyphosoma dans la Craie du Sud-Ouest (Actes 

de la Societe Linndenne de Bordeaux, T. 31). 

25. Desmoulins. Etudes sur les Echinides. 

26. P. DE LoRioL, in Pictet, 1867. Faune Terebr. diphyoides de Berrias; Melanges 

Pal., 2 serie. 

27. P. DE LoRioL, in Pictet, 1868. Etude provisoire des Fossiles de la Porte de 

France, d'Aizy, et de Lemenc ; Melanges Pal., iv. 

28. P. DE LoRioL et G. Cotteau, 1868. Monographic de I'etage Portlandien de 

I'Yonne (Bulletin Soc. Sc. Hist, et Nat. de I'Yonne, 2e serie, T. 1. 

29. P. DE LoRiOL et Ed. Pellatt, 1866. Monogr. de I'etage Portlandien de Boulogne- 

sur-Mer (Mem. Soc. de Physique et d'Hist. Nat. de Geneve, T. 19), et Monogr. 
des Etages superienrs de la formation Jurassique de Boulogne-sur-Mer (Meui. 
Soc. Phys. et Hist. Nat. de Geneve, T. 23 et 24). 

30. P. DE LoRiOL, E. RoYER, et H. Tombeck, 1872. Monogr. pal. et geol. des etages 

sup. de la formation Jurassique de la Haute Marne (Memoires de la Soc. 
Linneeune de Normandie, vol. xvi). 

31. DujARDiN et Hupi, 1862. Histoire Naturelle des Zoophytes Echinodermes. 

32. Etallon, 1860. Rayonnes du jurassique superieur de Montbeliard. 

33. Etallon, 1864. Paleontologie du Jura Graylois (Mem. Soc. d'Emulation du 

Doubs, 3e serie, vol. viii). 

34. Etallon, ] 860. Etudes Paleontologiques sur le Corallien du Haut Jura. 

35. Thurmann et Etallon, 1862. Lethsea Bruntutana (Memoires de la Societe Helv. 

des Sc. Naturelles). 

36. OosTER, 1865. Synopsis des Echinodermes fossiles des Alpes Suisses, 

37. OosTER, 1869-72. Protozoa Helvetica. 

38. P. DE Loriol, 1863. Descr. des animaux invert, foss. du necomien du Saleve. 

39. P. DE LoRioL, 1866. Descr. des foss. coralliens, Valangiens, et Urgoniens du Saleve, 

in A. Favre, Recherches geologiques sur la Savoie, &c. 

40. P. DE LoRioL, 1868. Monogr. des conches de I'etage Valangien d'Arzier (Materiaux 

par la Paleontolog. Suisse, publics par F. J. Pictet). 

41. P. DE LoRioL, 1869, in P. de Loriol et V. Gillieron. Monogr. de I'etage Urgo- 

nien du Landeron (Mem. de la Soc. Helv. des Sc. naturelles). 
42a. E. Desor et P. de Loriol, 1868 and 1872. Echinologie Helvetique, lere partie, 
Echinides jurassiques. 



A RETROSPECT. xv 

42(5. P. DE LoRiOL, 1873. Echiiiologie Helvetique, 2e partie, Echinides cretaces 
(Materiaux pour la Paleontologie Suisse, publies par F. J. Fictet). 

4.2c. P. DE LoRioL, 1875-76. Echinologie Helvetique, 3e partie. Echinides tertiaires 
(Memoires de la Soc. paleont. Suisse, vol. ii et iii). 

43. G. CoTTEAU, 1875. Note sur les Echinides cretaces du Hainaut (Bull. Soc. geol. 

de France, 3e Serie, T. II). 

44. G. CoTTEAU, 1878. Descr. des Echinides du Calcaire grossier de Mons. (Memoires 

de I'Acad. de Belgique, T. 42). 

45. G. CoTTBAU, 1880. Descr. des Echinides tertiaires de la Belgique (Memoires de 

I'Academie de Bruxelles, T. 43). 

46. G. CoTTEAU, 1870. Descr. de quelques especes d'Echinides de Suede (Bibl. de 

I'ecole des Hautes Etudes, Sc. naturelles. T. 2). 

47. QuENSTEDT, 1875. Die Echiniden. 

48. Cl. ScHLtJTER, 1869. Fossile Echinodermen des nordlichen Deutschlands (Verh. 

der nat. Ver. der Preuss. Rheinlandes, vol. xxvi). 

49. Cl. ScHLtJTER, 1870. Diagnosen neuer fossilen Echinodermen (Verh. der nat. 

Verh. Preuss. Rheinlands, vol. x.xvii). 

50. ScHLOENBACH, 1869. Bcitrag zur Alters Bestimmnung der Grunsandes v. Roth- 

enfelde (Leonh. und Geinitz, Neues Journal fiir Miner., &c., 1869). 

51. Dames, 1872. Die Echiniden der nordwest. deutschen Jura Bildungen (Zeitsch. der 

Deutschen. Geol. Gesell., vol. xxiv). 

52. Geinitz. Das Elbthalgebirge in Sachsen (Palseontographica). 

53. ScHAFHAUTL, 1863. Siid-Bayerns Lethsea geognostica, Kressenberg. 

54. ZiTTEL, 1879. Handbuch der Palaontologie, Vol. I, 3e Livr. 

55. CoTTEAU, in Zittel, 1870. Fauna der aelteren Cephalopoden filhrenden Tithon 

Bildungen. 

56. Laube, 1867. Die Echinodermen des braunen Jura von Balin (Denkschr. der K. 

K. Akad. der Wissenschaft., Wien, vol. xxvii). 

57. Laube, 1871. Die Echinoiden der Oesterreich-Ungarischen oberen Tertiar Ablager- 

ungen (Abhandlungen der K. K. geolog. Reichsanstalt, vol. v). 

58. Laube, 18G9. Ueber Oolaster, neues Echin. Gesch. von der Eocenen Schichten in 

Mattsee in Oesterreich (Leonhard und Geinitz, Neues Jahrb. fiir Mineralogie, 
1869, f. 454). 

59. R. IToRNESs, 1875. Die Fauna des Schliers in Ottnang (Jahrbuch der K. K. geoL 

Reichtanstalt, vol. xxv). 

60. LoczY, 1877. Echinoiden aus den neog. Ablag. des weissen Korosthaler (Terme 

szetrajzi Tuzetck, 1st Heft). 

61. Dr. Al. DE Pavay, 1873. Geologic Klausenburgs und seiner Unigebung (Mitth. 

aus den Jahrbuch. der Konigl. Ung. 'Geolog. Anstalt, vol. i). 



xvi BRITISH FOSSIL ECHINODERMATA. 

62. Dr. Al. de Pa vat, 1874. Die fossilen Seeigel des Ofner Mergels (Mitth. aus den 

Jahrbuch. der Kon. Ung. geol. Anstalt, vol. ii). 

63. Taramelli, 1874. Nota sopre alciini Ecliinidi del Istria (Atti del Reale Istituto 

Venete, Serie iv, Tome 3). 

64. Taramelli, 1868. Note sopra alcuni Echiiiidi cretacei e teiziarii del Fiiuli (Atti 

del Reale 1st. Veneto, Serie 3, vol. xiv). 

65. BiTTNER, 1880. Beitrage zur Kenntniss Alttiarer Ecliiniden fauneu der Siidalpen 

(Beitrage zur Palaontologie von Oesterreich. Ungarn., vol. i). 

66. ScHAUROTH, 1865. Verzeichniss der Versteinerungen in Herzogl. Natur. Cabinet 

zur Coburg. 

67. Laube, 1868. Ein Beitrag zur Kenntniss der Echinodermen des Vicentinischen 

Tertiar-Gebietes (Denkschriften der Wiener Akademie der Wiss., vol. xxix). 

68. Dames, 1877. Die Echiniden der Vicentinischen and Veronesischen Tertiaerabla- 

gerungen (Pal^ontographica, vol. xxv). 

69. Manzoni, 1873. II Monte Titano. 

70. Manzoni et Mazzetti, 1878. Echinodermi nuovi delle Molassa miocenica di Mon- 

tese (Atti della Soc. Toscana di So. Nat.). 

71. Manzoni, 1878. Gli Echinodermi fossili dello Schlier delle colline di Bologna 

(Denkschriften der Wiener Akademie der Wiss., vol. xxxix). 

72. Manzoni, 1880. Echinodermi fossili della Molassa Serpentinosa (Denkschriften 

der Wiener Akademie der Wiss., vol. xlii). 

73. Gemellaro, 1871. Studi paleont. sulla Fauna del Calc. a Ter. janitor del nord di 

Sicilia, iii. 

74. Stoppani, 1863. Paleontologie Lombarde, 3e serie. Infra-lias de Lombardie. 

75. CoTTEAU, 1860. Note sur quelques Echinides recueillis en Espagne par M. de 

Verneuil (Bulletin Soc. Geol. de France, 2e serie. Tome 17). 

76. CoTTEAU, 1879. Notice sur les Echinides urgoniens recueillis par M, Barrois dans 

la Province d'Oviedo (Annales des Sc. geologiques, x). 

77. Dr. T. Wright, 1864. On the Fossil Echinidge of Malta (Quarterly Joimial of 

the Geol. Soc. of London, vol. xx). 

78. Dames, 1877. Echiniden fauna von der Insel Melos. (Sitzungs-Berichte des 

Gesell. Naturforscher zu Berlin, 1877). 

79. P. DE Loriol, 1877. In the Etude stratigraphique de la Partie S. 0. de la Crimee, 

par Ernest Favre. 

80. CocjUAND, 1862. Geologic et Paleontologie de la Province de Constantine. 

81. CoTTEAU. Peron et Gauthier, 1873-1881 (Echinides fossiles de I'Algerie, 

7 fascicules). 

82. CoQCAND, 1880. Etudes supplementaires sur la Paleontologie Algerienne. 

83. Etheridge, 1872. Description of a new genus of fossil Scutelloid Echinoderm 

from Saffe, Morocco (Quart. Journ. Geol. Soc. of London, vol. xxviii). 



A RETROSPECT. xvii 

84. Eraas, 1867. Aus dera Orient. (Wiirttemb. Naturn. Jalireshefte, 1867). 

85. P. DE LoRiOL, 1880. Monographie des Echinides nummulitiques de I'Egypte 

(Mem. de la Soc. de Pliys. et d'liist. nat. de Geneve, T. 27). 

86. P. DE LoRiOL, 1881. Beschreibiing deraus seiner Reise niit der Rolilfsclier Expe- 

dition ; von Herrn Prof. Zittel mitgebrachten Ecliiniden (Pateontographica). 

87. Stolitzka, 1873. Monograph of the Echinodennata of the Cretaceous Deposits in 

Sonth India (Memoirs of the Geological Survey of India). 

88. Duncan, 1865. Descr. of the Echinodermata from the Strata on the S. E. Coast of 

Arabia, and Bagh on the Nerbudda (Quart. Journ. Geol. Soc. London, vol. xxi. 

89. Duncan, 1867. Descr. of some Echinoderms from the Cretaceous Rocks of Sinai 

(Quart. Journ. Geol. Soc. London, vol. xxiii). 

90. Cotteau, 1869. Notice sur les Echinides recueillis par M. Lartet en Syrie (Bull. 

Soc. geol. de France, 2e serie, T. 26). 

91. Eraas, 1878. Aus dem Orient, ii (Geolog. Beob. am Libanon). 

92. Th. Fuchs, 1880. Ueber einige Tertiare Echiniden aus Persia (Sitzungsber. der 

Wiener Akademie der Wiss., vol. Ixxxi). 

93. V". Fritsch, 1877. Die Echiniden der nummulitenbildnngen von Borneo 

(Palseontographica) . 

94. ZiTTEL, 1869. Fossile Mollusken xmd Echinodermen aus Neu-Zeeland (Novara- 

Expedition, vol. i). 

95. Laube, 1869. Ueber einige fossile Echiniden von den Murray^ Cliffs in Sud 

Australien (Sitzungsberichte der Wiener Akad. der Wiss., vol. lix). 
96«. Etheridge, 1875. On Australian Tertiary Echinoderms (Quart. Journ. Geol. 

Soc, vol. xxxi). 
965. Etheridge, 1875. Descr. of a New Species of the genera Hemipatagus from the 

Tertiary Rocks of Victoria, Australia (Quart. Journ. Geol. Soc. of London, 

vol. xxxi). 

97. Duncan, 1876. On the Echinodermata of the Australian Cainozoic Deposits 

(Quart. Journal. Geol. Soc. London, vol. xxxiii.) 

98. Remond, 1863. Proceed. California. Acad, for 1863. 

99. Gabb, 1869. Geol. Survey of California ; Palaeontology, vol. ii. 

100. Conrad, 1865. Catalogue of the Eocene Echinodermata, &c., of the United 

States (Proceed. Acad. Nat. Sc, Philadelphia, 2nd series, vol. ix). 

101. GuppY, 1866. West-Lidian Echinoderms (Quart. Journ. Geol. Soc, London, 

vol. xxi). 

102. Cotteau, 1875. Description des Echinides Tertiaires des Antilles (Mem. de 

I'Academie de Suede, vol. xiii). 

103. Cotteau, 1871. Notice sur le genre Asterostoma (Mem. Soc. Geolog. de France, 

2e Serie, T. 9). 

104. Philippi, 1860. Reise in die Wiiste Atacama. 



xviii BRITISH FOSSIL ECHINODERMATA. 

105. Steinmann, 18S1. Die Kenntniss der Jura und Kreideformation in Caracoles, 

Bolivia. 

106. P. DE LoRioL, 1876. Note sur quelques esp. nouvelles appartenant a la Classe de 

Echinodermes (Mem. Soc. de Phys. et d'Hist. nat. de Geneve, T, 24). 

107. Alexander Agassiz, 1872-74. Revision of the Echini (Illustrated Catalogue of 

the Museum of Compar. Zoology at Harvard College, No. 7). 

108. Wyville Thomson, 1873. The Depths of the Sea, 

109. Wyville Thomson, 1874. On the Echinoidea of the "Porcupine" Deep Sea 

Dredging Expedition (Philos. Trans, of the Royal Soc. of London, vol. clxiv). 

110. Alexander Agassiz, 1874. Zoological Results of the Hasler Expedition; Echini 

(Illustrated Catalogue of the Museum of Compar. Zoology at Harvard College, 
No. 8). 

111. Alexander Agassiz, 1878. Report on the Results of Dredging .... by the 

U. S. Coast Survey Steamer " Blake ; " Echini (Bull. Mas. of Compar. Zool. at 
Harvard College, vol. v. No. 9), 
Alexander Agassiz, 1880. Idem., idem. (Bull. Mas. of Compar. Zool. at 
Harvard College, vol. viii. No. 2). 

112. Wyville Thomson, 1877. The Voyage of the " Challenger; " the Atlantic. 
Alexander Agassiz, 1879. Preliminary Report on the "Challenger;" Echini 

(Proceed. Amer. Acad, of Arts and Sciences, vol. xiv). 

113. LovEN, 1874. fitudes sur les Echinoidees (Kougl. Svenska Veteuskapt. Akade- 

miens Handlingar, vol. xi)." 



THE 



PALJIONTOGRAPHICAL SOCIETY. 



INSTITUTED MDCCCXLVII. 



LONDON 



MUCCCLXIT. 



A MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODERMATA 



FROM 



THE CRETACEOUS FORMATIONS. 



BT 



THOMAS WRIGHT, M.D., F.R.S. Edin., F.G.S., 

COBEESPONDING MEMBER OP THE HOTAL SOCIETY OF SCIENCES OF LIEGE, 
AND SENIOR SUEGEON TO TUE CHELTENHAM HOSPITAL. 



VOLUME FIRST. 



PART FIRST. 
ON THE CIDARID^. 



LONDON: 

PRINTED FOR THE PAL^ONTOGRAnilCAL SOCIETY. 

1864. 



J. E. ADL4RD, PRINTKR, BARTHOLOMEW CLOSE. 



A MONOGRAPH 



ON THE 



CRETACEOUS ECHINODEKMATA. 



ON THE CRETACEOUS GROUP. 

The Cretaceous group, as a whole, as developed in England, has been so fully 
described by Conybeare and Phillips,^ and its subdivisions by other authors,^ that it 
appears to be unnecessary to devote any great space to this branch of the subject, beyond 
an epitomized outline of the subdivisions of the Cretaceous rocks, with brief notes on the 
species of Ecldnidce found therein, and the co-relation of these stages with their equivalent 
zones of life in the Cretaceous systems of the Continent of Europe ; and as the Isle of 
Wight exhibits some of the best coast-sections of the Cretaceous rocks in the British 

' The ' Outlines of the Geology of England and Wales ' contains a most able account of this formation. 

2 Tiie following, among many others, may be consulted for important information on the Cretaceous 
formation : — Dr. Fitton's various memoirs in the ' Geol. Transactions,' and ' Quarterly Journal of the Geol. 
Soc. ;' Sir H. De La Beche, " On the Chalk and Greensand of Lyme Regis," ' Geol. Trans.,' vol. ii ; Young 
and Bird and Professor John Phillips on the Geology of Yorkshire ; Dr. Mantell's works on the 
Geology of Sussex ; Samuel Woodward's 'Geology of Norfolk ;' Dixon's ' Geology of Sussex.' The various 
memoirs in the ' Quarterly Journal of the Geol. Soc' on the Cretaceous Rocks, by Professor E. Forbes, 
Messrs. Lonsdale, Rose, Austen, Cunnington, Morris, Weaver, Rose, Clarke, Bunbury, Bowerbank, 
R. C. Taylor, Ibbetson, Toulmin Smith, D. Sharpe. The Manuals of Geology, by Sir H. De La Beche, 
Sir Charles Lyell, and Professor Jukes ; and the " Geology of the Isle of Wight," by Mr. H. W. Bristow, 
in the ' Memoirs of the Geological Survey.' The reader will likewise find most valuable information 
in Le Vicomte D'Archiac's ' Histoire des Progrcs de la Geologic,' tom. iv and v, " Sur la Formation 
Cretac^e ;" the memoirs by M. E. Gueranger, in the ' Bull. Soc. Geol. de France ;' M. Cornuel's 
" Section of the Environs of Vassy " (' Mem. Soc. Geol. de France,' t. iv) ; M. Leymerie's " Memoir on 
the Department of the Aube" ('Mem. Soc. Geol. de France,' t. ivand v) ; and in the different important 
works by the late M, Alcide d'Orbigny. 

1 



2 CRETACEOUS GROUP. 

Islands, in their stratigraplucal order of superposition, I shall take these as a type of the 
whole, supplying any deficiency in the series by examples afforded by other localities. 

THE LOWER GREENSAND. 

The Lower Greensaiid, occupies an extensive tract in the southern part of the Isle of 
Wight, where it attains a thickness of nearly 900 feet; this great formation has been so 
carefully examined and well described by the late Dr. Eitton,^ in his stratigraphical 
account of the section from Athertield to Rocken End, on the south-west coast of the 
island, that I must refer the reader for full information to that valuable memoir for further 
details. Having worked several times over all the beds of that remarkable and most in- 
structive district, aud in my excursions had the advantage of the local knowledge and 
assistance of Dr. Eitton's collector and guide," I shall now merely attempt a generalized 
account of this section, for the purpose of pointing out the beds with which we are more 
immediately interested, in our description of the Echiuids contained therein. 

The entire series of the Lower Greensand beds, 809 feet in thickness, rise in succes- 
sion from the shore aud ascend into the cliffs between Atherfield Point and Rocken End, 
towards which they dip at an inclination of about 2°. 

The following Subdivision of the Atherfield Section was proposed Jjy Br. Fitton, in 

ascending order. 

Feet. Inches. 

I. Perna MuUeti Bed 5 3 

II. Atherfield Clay 60 

III. The Cracker Rocks 85 

IV. The Lower Grypheea Group 32 

V. Scaphites Group 50 4 

VI. Lower Crioqeras Group 16 3 

Vil. Walpeu Clays aud Sands 57 

VIII. Upper Crioceras Group 46 2 

IX. Walpen aud Ladder Sands 42 

X. Upper Gryphsea Group 16 

XI. Cliff-End Sands 20 

XII. Foliated Clay and Sand 25 

XIII. Sands of Walpen and Black-Gang Undercliff 97 

XIV. Ferruginous Sands of Black-Gang Chine 20 6 

XV. Upper Clays and Sand-Rock , 118 

XVI. Various Sands and Clays 118 4 

808 10 

1 " A Stratigraphical Account of the Section from Atherfield to Rocken End, in the South-west Coast of 
the Isle of Wight," ' Jour, of the Geol. Soc' vol. iii, p. 289, 1847- 

- Mr. Charles Wheeler, fisherman, at Ventnor, is the person alluded to, he has a most correct know- 
ledge of the range and position of all the beds, aud of their fossil contents, and is a most trustworthy 
guide to the Atherfield Section. 



LOWER GREENSAND. 3 

I. The Ferna beds, which here form the base of the Lower Greensand, rest upon 
Weald clay ; the junction between the lacustrine series of the latter with the marine 
deposits of the former exhibit no trace of disturbance; a thin seam of bone-bed, composed 
of the teeth of fish of lacustrine species, attest a change of conditions similar to that 
observed in some junction-beds in other formations, as between the Upper Keuper and the 
Lias, and the Upper Silurian and Devonian series. This junction, which is only sometimes 
visible, occupies about eight inches of vertical thickness ; on one occasion I succeeded 
in detaching a block of rock, about a foot thick, from the beds, the lower half of 
which contained the lacustrine shells of the Weald clay, whilst in the upper half Perna 
Mulleti, Desh., Exo(/yra sinuata, Sow., and other Lower Greensand shells, were found. 
The Perna beds rise from the base of the cliff, at a point a few yards to the east of the 
flag-staff of the coastguard-station ; they consist of dark-blue sandy clay and greenish 
sand, forming in parts a very hard rock, and characterized by that remarkable shell Perna 
Mulleti, Desh., which is not found in any other bed in the section. Nearly one hundred 
species of marine shells are found in the Perna beds ; among these Nautilus Requinianus, 
d'Orb,, and Exogyra sinuata. Sow., appear for the first time, of very large size, and 
Hemipneustes Fittonii, Forb., among the Echinida, with the remains of fish belonging to 
the genera Lamna, Odontaspis, Saurocephalxs, Hyhodus, &c. 

n. The Jtherfleld Clay is of a drab colour, passing into bluish-gray, and contains 
flat nodular masses. Ammonites Deshayesii, Leyra., Pinna Robinaldina, d'Orb., and several 
other species of Conchifera, with the bones of a Turtle, and the remains of Echinidae, are 
found in this bed. 

in. The Crackers, so called from the noise produced by the waves dashing over the 
ledges formed by these rocks on the shore, are the most interesting fossiliferous group of 
the entire series, and consist of alternations of sandy clays and clays, and two layers of 
ferruginous sandy nodules. All the clays resemble Pullers' earth, and the sand between 
the nodular concretions in the lower bed is sometimes indurated into an imperfect stone. 
The lower part of this group is a brown clay and sand, called the Lower Lobster bed, from 
the number of Asfacus Vectensis, Bell, found therein ; the succeeding beds are sands, 
containing concretionary masses of sandstone full of beautiful fossil shells. Ammonites 
Deshayesii, Leym., Pholadomya Martini, Porb., Myacites plicata. Sow., Corbula striatula. 
Sow., and several other Conchifera. Many of the Myadce are found in the upright position 
they assumed during life. The lower sandstone, from a foot to eighteen inches in thick- 
ness, is almost entirely made up of GervUlia aviculoides. Sow., Triyonia Dadalcea, Park., 
Ammonites Deshayesii, Leym., and other shells. The upper layer of sandstone contains 
coniferous wood and a Teredo, and the upper clays are fossiliferous throughout. In the 
concretionary nodules of the lower series of this group I have collected Pseudodiadema 
Autissodorense, Cott., P. Ibbetsoni, Forb., and Hemipneustes Fittoni, Porb., Avith the 



4 LOWER GREENSAND. 

beautiful winged shells BosteUaria glabra, Forb., E. reli/sa, Sow., Pterocera Fittoni, 
Forb., and several species of Cerithia, as Cerithium turriculatitm, Forb., C. Neocomiense, 
d'Orb., and C. PMUipsi, Leym. 

IV. The Lower Gryj)haa or Exogyra Group has for its base a thick bed of ferrugi- 
nous sand, overlain by sand containing Perna alaformis, Sow., and Terebratula sella. Sow., 
in great abundance, in thin seams of sand. The zones with Exo(jyra sinuata, Sow., which 
here are very large, are found in the upper part of the group. 

V. The ScaphUes Group forms three beds ; the lowest is composed of brown ferru- 
ginous sand, containing Exogyra sinuata, Sow., Terebratula sella, Sow., Bhytichonclla 
Gibbsiana, Sow. ; and of the Echinidse I found Cardiaster Benstedi, Forb., and Nmleolites 
Olfersii, Ag. ; the middle beds, about two feet in thickness, contain layers of nodules 
enclosing Scaphites giyas, Sow., and ScaphUes Hillsii, Sow. ; the upper consist of thick 
beds of greenish sand, containing, in the upper part, fine large specimens of Exogyra 
sinuata, ^ow. 

VI. The Loioer Crioceras Group consists of ranges of large sandy nodules, enclosing 
Crioceras Bowerbankii, Sow. ; the lowest range rises on the west of Whale Chine, and is 
succeeded by two other ranges, all three enclosed in sand about nine feet thick ; the 
lowest, furnishing the best fossils, passes the bottom of Whale Chine, from whence I 
have obtained several large specimens. 

VII. The Walpen and Ladder Sands and Clay extend from the east of Walpen to half 
way between Ladder and Whale Chines, where they are well seen ; the lower half of this 
group contains Ammonites Martini, d'Orb., and a large Gryphcea ; the upper half, 
which is clayey below and sandy above, contains Dentalium, Myacites mandibula, Sow., 
Pinna Bobinaldina, d'Orb. 

VIII. The Upper Crioceras Group consists of sandy nodules imbedded in sand, and 
contains Crioceras Botuerba^ihii, Sow., Ammonites Martini, d'Orb., Gervillia solenoides, 
Defr., Terebratula sella. Sow., and several other shells. This group is seen for some 
distance along the shore east of Walpen Chine, which is crossed by it, as are also Ladder 
and Whale Chines. 

IX. The Walpen and Ladder Sands consist of gpcenish and gray sand, with a layer 
of large fossiliferous nodules at the base, containing Serpulce, Thetis, Gervillia, Cucullcea, 
Corbula, and other shells, together with an Urchin belonging to the genus Brissus. 

X. The Second Gryphaa or Exogyra Group. — The lower part of this group consists of 



LOWER GREENSAND. 5 

sand and clay containing small nodules enclosing a Brissus, Ammonites Martini, d'Orb., 
and detached valves of Exogyra sinuata ; above are three or four ranges of Exoc/yra 
sinuata, Sow.; the parallel edges of these large shells, as seen in the cliff, indicate three or 
four continuous strata, with irregular clusters between them. The second or upper 
Gryphaea group appears at low water at Shankliu, where the several ranges of Exoyyrcs 
are seen rising beneath each other. Varieties of this shell appear to me to charac- 
terize different beds ; for example, the specimens of Exoyyrce from the Crackers and 
Lower Gryphaea group present marked differences when compared with shells of the 
same species from the Upper Gryphtea group. A similar observation has been made by 
M. Cornuel on the Exoyyrce collected by him near Vassy, in France. This geologist 
assured Dr. Fitton " that he could at once assign each variety of form to a special place 
in the section of that vicinity." Small fragments of vegetable remains {Lonchopferis 
Mantellii, Brong.) occur not only in these beds, but nearly throughout the entire 
formation. 

XL The Cliff-End Sands consist of uniform sand about fourteen feet thick, with a 
subordinate bed of fossiliferous clay containing Triyonia Dcedalcea, Park., in the lower part, 
and plant-like pyritiferous concretions in sand and clay in the upper part. 

XIL Foliated Clay and Sand. — Consist of alternations of dark- blue clay and greenish, 
translucent, siliceous sand, containing nodules of pyrites and large irregular masses of 
coarse sandstone. These beds are well seen in Walpen and Black-Gang Chines, but no 
fossils have hitherto been found in them. 

XIIL Sands of WaljK'n and Black-Gany Under cliff. — This group commences with 
a bed, about ten feet in thickness, of loose white sand, with thin laminae of gray clay ; 
this is succeeded by seventy feet of greenish and brownish sand overlain by seven 
feet of coarse ferruginous sand, with rounded grains of iron-ore in the lower half of 
the bed, and by twelve feet of alternating sand and clay, making a total of 100 feet. 
There are only very few fossils in this group — Myacites plicata, Sow., and M. man- 
dibulata, Sow. 

XIV. The Ferruginous Bands of Black-Gang Chine rise from the shore between Rocken 
End and Black- Gang Chine, and form the uppermost fossiliferous group of the Lower 
Greensand ; they are composed of brown and yellow sand, with layers of ferruginous 
concretions, overlain by a bed of ferruginous sandstone, about five feet in thickness ; the 
group is about twenty feet in all, and is the equivalent of the zone of Lower Greensand at 
Parham Park, and other places in Sussex, and near Sandgate in Kent. The sands in this 
group are fossiliferous throughout, and the species identical with those found in the Perna 
bed and Cracker rocks at the bottom of the section. 



6 GAULT. 

XV. The Tipper Clays and Sand Rock consist of forty feet of dark clay with pyrites, 
separated by eighteen feet of white and green-coloured sand from a mass of clays and 
sands sixty feet thick. The bed 47 of this group is dug near Rocken End for the 
manufacture of glass ; it contains no fossils. 

XVI. Various Sands and Clay constitute the remainder of the section ; they measure 
about 120 feet in thickness, and are overlain by the Gault. 

The Lower Greensand represents the upper portion of the rocks known as the 
Terrain Neoconiien of MM. Thurmann and d'Orbigny ; Terrain Jurassique superieur of M. 
Matheron ; Couches adosse'es au Jura of Von Buch ; Formation Waldienne et Neocomienne 
of I\IM. Dufrenoy and Elie de Beaumont ; Calcaire a Sjmtaiiyues, L'Argile ostreene, of 
M. Cornuel ; Arr/iles tegulines et gres vert and " Terrain Neocomien " (Wealden) of M. 
Leymerie. The French geologists consider the Wealden clay and Hastings sand as the 
inferior, and the Lower Greensand the superioi-, portion of their Neocomien, whilst English 
geologists describe the Wealden and Lower Greensand as distinct formations. 



THE GAULT. 

In several coast-sections the Gault is seen separating the Lower from the Upper 
Greensand ; this bed of dark clay is called " the blue slipper," from the tendency of the 
overlying strata to form landslips by gliding over its surface. The charming scenery of 
the Undercliff has been in a great measure produced by the foundering of the'Upper 
Greensand and Cretaceous rocks over the Gault clay ; the rain-water having saturated these 
porous beds, bursts forth in springs, which wet the surface of the clay, and occasions 
slips of the superincumbent strata. A rich fertile soil is thus formed upon a broad terrace 
of stiff clay, exposed to the south, and sheltered from the north by a high mural 
escarpment of Upper Greensand. Under these favourable physical conditions vegetation 
springs up in great luxuriance, on a natural terrace high above the sea, producing a 
coast-scene unequalled in beauty in the British Isles. 

The Gault is about 100 feet in thickness, and in the Isle of Wight contains few fossils, 
as Inocerainus sulcatus, Sow., and/, concentricus. Sow. ; near Folkstone and Charmouth it 
lias yielded many beautifid shells in high preservation. I shall figure some rare Echinidce 
from this bed at Folkstone. 

The Bed Chalk is a remarkable stratum, supposed to be the equivalent of the Gault ; 
it is limited both in thickness and extent, for if we take, says the Rev.^T. Wiltshire, one 
hundred feet as its maximum and four feet as its minimum thickness, and 100 miles as its 
extreme length, we shall not be far from the truth. It is said to be peculiar to the English 
Chalk. It is well exposed at Speeton, near Filey, on the Yorkshire coast, and at Hunstanton 
Cliff, near Lynn, Norfolk ; in both localities it is a red calcareous rock, deeply coloured by 



RED CHALK. 



the peroxide of iron, and containing minute siliceous grains, and small pebbles of chal- 
cedony, quartz, flint, &c. This rock from Hunstanton yielded by analysis carbonate of 
lime, with a little alumina, 82'3 ; peroxide of iron, 6"4 ; silica, 11'3 = ; 100. 




Hunstanton Cliff',^ of which the annexed woodcut gives an idea, consists of five 
different beds — 1st, the uppermost, or white chalk, is forty feet thick ; 2nd, bright-red 
chalk, four feet ; 3rd, yellow sandy bed, ten feet ; 4th, a dark brown pebbly stratum, forty 
feet ; and 5th, a dark-coloured bed, almost black, twenty feet. 

These divisions at Hunstanton, the Rev. T. Wiltshire states, do not run into each other, 
but are quite distinct ; the red chalk is as clearly separated from the white as though the 
one had been covered by a broad band of paint, and the same remark holds true of the others. 
When the sun shines upon the cliff, and lights up the bright white, bright red, the pale 
yellow, and the dark brown and black, and casts a shadow over the mass of gaily tinted 
materials at the base, a picture is produced not easy to be surpassed in beauty, and 
certainly not to be fully appreciated unless it is seen. 

The Red Chalk is very fossiliferous, containing Ammonites, Belemnites, Brachiopoda, 
Echinidse, and Corals. 

In compliance with my request, ray friend the Rev. T. Wiltshire, F.G.S. has kindly 
sent me the following note, embodying his latest observations on the Red Chalk at Speeton.' 

" In answer to your inquiry respecting the natural section of the Red Chalk at the 

1 For ample details, see the Rev. Thos. Wiltshire, on the 'Eed Chalk of England.' 
' To this gentleman's kindness I am likewise indebted for the above woodcut, copied from a water- 
colour drawing ii his collection. 



S SPEETON CLAY. 

most northern extremity of that bed in England, viz., in the neighbourhood of the little 
Yorkshire village of Speeton, I send you a few scanty notes. On my first visit to 
Speeton, some years since, I imagined, as I suljsequcntly described in the second volume 
of the 'Geologist Magazine,' and in the 'Proceedings of the Geologists' Association' for 
1859, that the Red Chalk in Yorkshire consists of a couple of bands of a highly coloured 
marl, of about thirty feet in thickness from top to bottom, and that its fossils are of such 
forms as to imply a close relationship with Gault species. This opmion I derived from seeing 
the section in a gulley to the east of the village ; but subsequent investigations made upon 
the shore under the clifT, at a mile or more from the ravine, showed me that my former ob- 
servations were slightly incorrect, and that the Red Chalk, in that part of Yorkshire at least, 
contains two more additional coloured bands, and that its total thickness from top to bottom 
is not less than 100 feet, and that its upper portion belongs to the Lower Chalk series. 

" The highest bed of Red Chalk at Speeton may be seen rising from the beach at a 

very gentle inclination, at about a mile and a half to the south-east of the gulley. This 

bed, which is of varying thickness throughout its course, may be estimated as being on 

an average about five feet thick ; it is of a pale pink colour, very hard, and presents a 

strongly marked appearance from the white chalk, above and below, with which it 

is in contact. The fossils found in it are Bhjnchonella Mantelliana, Gri/ph(ea vesicu- 

laris, Biscoidea cylindrica, Holader subglobosus, Spines of Cidaris, Spines of Dindema 

small vertebrae and teeth, together with a considerable number of Terebratulin^ graciles. 

Above this bed, in the white chalk, are found Holaster subglobosus and Ammonites 

peramplus. The pink band just mentioned is followed by a greenish-yellow chalk, about 

forty feet thick, almost destitute of organic remains, except fragments of Inocerami, and 

marked by numerous thin layers of marl, not unlike those met with in the Lower Chalk of 

Sussex. The next bed in descending order is one of a light pink colour, about three feet in 

thickness, likewise destitute of fossils, with the exception of fragments oi Inocerami. This 

is followed by another stratum of greenish-yellow chalk, about nine feet thick, containing 

small GryphcBce, and Terebratulce semiglobosa, and PeUasles, but, like the two preceding 

beds, generally unfossiliferous. The greenish-yellow chalk is succeeded by five feet of 

white and red chalk, in thin bands, very deficient in organic remains, and this rests 

upon a pale-red band, about seven feet thick. Li the upper part of this last seven feet 

of red material are many Vermicularicp. umbonatce, and in its lower portion many 

small TerebratulcB and Inocerami. About ten feet of greenish-white chalk, somewhat 

hard, is the next bed, in which few fossils are to be noted except a Terebratula and a 

bone or two of a Star-fish. \\\ all these strata enumerated there is a marked absence of 

Belemnites, but in the succeeding and last bed, one of a bright-red colour, and more than 

thirty feet thick, they become exceedingly abundant. This red band -is the one from which 

most of the Red Chalk fossils from Speeton are derived ; it is exceedingly fossiliferous. Ii] 

its uppermost portion very large Terebrafido: may be obtained, and generally inany of an 

ordinary size; at about twenty feet below its commencement, Belemnites, Pentacrim, 



SPEETON CLAY. 9 

and sjMiies of a Cidaris occur, wliicli appear to be distinct from the Cidaris spines, ninety-four 
feet above, in the pink band. There are, moreover, no traces of IMastcr suhyhhosm nor 
Discoidea cylindrica in this bright-red bed ; and Ammonites cannot be seen, though so 
numerous in the Speeton Clay, upon whicli it rests. This red band gradually becomes 
nodular, and of a bluish cast, and gradually merges into the Speeton Clay. 

" Inland the Yorkshire beds put on a somewhat difierent appearance, for on the escarp- 
ment of the Wolds, as at Great Givendale, the beds of Red Chalk abound in pebbles 
and in Terehratitla bipUcafce, a feature that is absent at Speeton, though conspicuous at 
Hunstanton, in Norfolk. 

"A careful inspection of the fossils derived from the Red Chalk series of Yorkshire and 
Norfolk shows that the two extremities of the bed are very distinct in character, and have not 
much in common, and that the southern stratum is a moi'e littoral deposit than the northern." 

l\Iy friend John Leckenby, Esq., E.G.S., of Scarborough, having studied critically the 
fossils of the Speeton Clay, has kindly supplied the following note on that formation, from 
which it appears that until now the true relations of this deposit have not been clearly 
understood. 

" The Speeton Clay of Yorkshire, besides many minor subdivisions, presents two 
important and well-marked sections ; well-marked lithologically, still more so by their 
fossils. The line of separation midway, or nearly so in the series, is also distinct and clear, 
with no passage-beds indicating a transition from one set of conditions to another. Its 
entire thickness cannot be less than 400 feet, but in consequence of the denudation of the 
inclined edges of its beds it nowhere presents a continuous section of more than 150 feet. 

" The lower division is characterized in its upper beds by Ammonites and Gas- 
teropods, which I at one time felt inclined to refer to the O.xfordian system, and many 
palaeontologists yet contend that the thick coronated Ammonites v/hich here abound 
belong to the Oxfordian group. Without, however, doing violence to our preconceptions 
of stratigraphical relations, we shall find that they approach much more nearly to 
Portlandian types, as figured by d'Orbigny; &\\(\Aiii. (Jraye-w/z^^s cannot be distinguished 
from a common, but unpublished form, in the Speeton Clay. In the lowest beds of 
this lower division are found Am. inpUcatus, Am. cxcavatus (var. aUernatus, Von Buch), 
with univalve and bivalve shells identical with species which I have obtained from the 
Kimmeridge Clay of Lincolnshire, in a railway-cutting near Brigg. The line of demarcation 
before referred to is characterized by a thickish band of pseudo-coprolites, and by many 
remains of Saurian animals ; it would appear that here there has been a period of repose, 
during which the Saurian dwellers upon a shallow reef disported themselves, and that we 
have a well-marked division between the close of the Jurassic and the commencement of 
the Cretaceous period. A large and almost perfect example was lately procured and is now 
in the possession of Right Hon. Lord Londesborough, the lord of the manor of Speeton. 

" The habit of referring the whole of the Speeton Clay of Yorkshire to the Cretaceous 
period, in deference to established authorities, has hitherto prevented a clear reading of 

2 



10 UPPER GREENSAND. 

the evidence furnished by its fossils, and from the fact of so many of its Ammonites of 
the Oolitic type being found, not in situ, but in boulders, has led to the inference of the 
existence, at some remote period, in Filey Bay, of great beds of Oxford Clay similar in 
character to the Oxford Clay of the south of England. 

" The Ammonites can, however, with much more propriety, be referred to Portlandian 
types, and the wasted beds which have furnished the boulders doubtless pertain to the 
•same epoch. 

" Above the line of Saurian remains alluded to, all the fossils belong to the Cre- 
taceous type ; and amongst the exact representations of a Neocomian fauna many others 
are found which in general features closely resemble them. Amongst the former, Ammonites 
Dcshayesii, Leym., and Vermicularia Sowerhii may be mentioned, while Crioceras JBeanii, 
Phil., cannot easily be distinguished, if at all, from C. Cornuelianum, d'Orb. 

" If we seek for the equivalents of the Upper Greensand in the Speeton Clay, we must do 
so rather in the lower beds of Red Chalk which overlie that deposit than in the clay itself; 
and the frequent presence therein of Inoceramiis Coqiiandianus, d'Orb., favours this view. 

" The junction of the lowest beds of Speeton Clay with the Coralline Oolite cannot 
be traced along the coast, but may be seen at some distance inland, near the village 
of Grimstou, one of the stations on the line of railway between Malton and DritTiekl." 

The Gault is the equivalent of the Eta^e Albion of d'Orbigny, and tlie Gaulf of the 
■Germans. 

THE UPPER GREENSAND. 

This formation forms an important feature in the physical geology of the Isle of 
"Wight ; in Compton and Sandown Bays it is seen in its relative position to the Lower 
Greensand below and the Clixilk above, and in the Undercliff it forms a bold, mural, 
light-coloured escarpment, with rugged lines of cherty beds, producing a fine effect above 
the rich foliage which clothes the undercliff. According to H. W. Bristow,^ Esq., F.G.S., 
tlie Upper Greensand under St. Catherine's Down is about 155 feet thick; the lower fifty- 
five feet consist of "bluish, sandy, micaceous beds, throwing out water at their janctiou 
with the Gault, and passing upwards into yellowish-gray sand, also micaceous, with 
sandstone and some chert, forty feet thick. Sandstone and chert imbedded in sand 
make up the greater part of the rest of the section, the middle portion of which is 
mostly blue chert based upon seven feet of sandstone, inclosing a bed of freestone four 
feet thick, whilst the uppermost fifteen or twenty feet consist of calcareous sandstone, 
forming a vertical face at the summit of the cliff." 

In the island the remains of Echinidoe are not abundant in these beds ; the Upper Green- 
sand, near Warminster and Devizes (Wilts) ; Blackdown (Devon) ; and near Charinouth 
(Dorset), and Cambridge, are the best localities for the fossil Echinodermata of this formation. 
1 " Jlemoirs of the Geological Survey," the ' Geology of the Isle of Wight,' p. 24. 



LOWER CHALK, AND CHALK-MARL. 11 

CHLORITIC MARL. 

At the base of the Chalk, and dividing that formation from the Upper Greensaud, is 
a remarkable fossiliferous bed, full of green specks of silicate of iron, and called, in 
consequence, Chloritic Marl, which at St. Catherine's Down measures five feet in thick- 
ness. This Marl is characterized by a suite of fossils, some of which, as Scc/jMtes iequalls, 
Sow., here appear for the first time, and seem to be special to the bed ; with these are 
found Ammonites varians. Sow., Amm. sjjieiidens, Sow. ; several Protozoa belonging to 
the genera Spoiiffia, SipJionia, and Sci/pJda ; Echinodermata, as Ananchjtes lavis, Deluc ; 
Catopijgus carinafus, Goldf. ; and Biscoidea subuculus, Leske ; together with several species 
of MoLLUscA. The same stratum occurs near Chardstock, from whence I have obtained 
many fine specimens of Psciidodiadcma tumidum, Eorbes, P. siibnudim, Ag., Pedinopsis, 
Holedypm, and several other species, most of which are common to this rock and the 
Upper Greensand, of which it probably forms the uppermost bed. 

The Upper Greensand appears to correspond to the Glaucoiiie craycuse of the French, 
the Tourtiu of the Belgians, the Grunsand of the Germans, and the Etagc Cenomanicn of 
d'Orbigny. 

THE LOWER CHALK, AND CHALK-MARL. 

The Chalk formation occupies a large area in the Isle of Wight, and in the southern 
and eastern parts of England. It consists of nearly piu-e carbonate of lime, and in many 
cases is almost entirely composed of microscopic shells, either fractured or entire. My friend 
H. C. Sorby, Esq., F.G.S., by preparing thin slices of chalk on slides of glass for microscopic 
examination, has shown that many beds of that rock consist of from 90 to 95 per cent, 
of the cases of Forcminifera, and of comminuted shells. The chief difference between 
the Upper or soft white Chalk, and the Lower or hard Chalk is caused by the filling up of 
the cavities of the shells by calcite or crystalline carbonate of lime, wlierc it has pro- 
bably been deposited by infiltrating water, which has carried away some of the lime in 
percolating through the higher beds. The Chalk formation is divided into Chalk-marl at 
the base. Lower or hard Chalk without flints, and soft or Upper Chalk with flints. In the 
Isle of Wight the whole formation is 1300 feet in thickness, whilst in England it varies 
from 600 to 900 feet. 

The Lower Chalk near Dover is of a grayish colour, and much indurated in parts. It 
is very rich in Echinida, and contains several new^ species. Unfortunately, many of the 
finest specimens are impregnated with iron, and perish by the decomposition of the 
pyrites. At Lewes, in Sussex, it is a hard, close-grained rock, with an earthy fracture, 
and contains many urchins in fine preservation. 

The following section, by the Rev. W. D. Couybeare, of the Clialk cliff's near Dover, 



12 WHITE CHALK. 

exhibits so well the position and relation of the Gray Chalk, which contains so many 
fine Ecliinidee, that I have introduced it here for reference. The strata lie in the following 
descending order, and are collectively about 820 feet thick. 

1st. The Chalk n-UJt 'niiiiierous fints ; it is about 350 feet thick, and may be thus 
divided : 

I. With few organic remains. 

II. A Ijed consisting chiefly of organic remains in wliich numerous flints of 

peculiar forms are interspersed ; and a iew beds of flints run along it. 

2nd. The Chalk with few Jlhits. This stratum is about 130 feet thick. 
3rd. The Chalk xcithout flints is 140 feet thick, and consists of — 

I. A stratum containing very numerous and thin beds of organic remains, 

90 feet thick. 

II. A stratum about 50 feet thick, witli few organic remains. 

4th. The Graij Chalk. This is estimated to be not less than 200 feet in thickness, 
and is that from which has been collected most of the fine specimens of Cidaris 
Bmccrhankii, Forb. ; Pseudodiadema ornatum, Forb. ; F. fumidum, Forb. ; P. 
variolare, Brong.; P. Brongniarti, Ag. ; P. Mackiei, "Wowd., Salenia Austeni, 
Forb. ; S. Clurkii, Forb. ; S. gihha, Forb. ; S. granulosa', Forb. ; and 5'. peta- 
lifera, Defr., with other specimens of Chalk-marl species. 

The Lower Chalk and Chalk-marl are represented on the Continent by the Untcre 
Kreide and Planer of the Germans, the Craie tuffeau of the Fi'ench ; and tlie Etage 
Turomcn of d'Orbigny. 

THE AVHITE CHALK. 

The uppermost ]5ortion of the Cretaceous formation extends across the island in an east 
and west direction, from the Needles to Culver Cliff, and all its beds are fully exposed in 
several magnificent coast-sections ; as these beds are nearly vertical or highly inclined 
at Alum and Scratchells Bays on the east, and at Culver Cliff's on the west, the sub- 
divisions of the whole Cretaceous formation, and the way the beds pass into each other, 
may be most satisfactorily ascertained. The bands of flints are well displayed in Scratchells 
Bay and Culver Cliffs, and there is a flne exposure of vertical Chalk strata in a pit on 
Brading Down ; in all these localities, and many others which it is imnecessary to 
enumerate, tlie flints appear as parallel layers at certain intervals in the strata, presenting 
a striking contrast from their blackness to the snowy aspect of the Chalk with wliicli they 
are interstratified. 

"In consequence of the high angle at which the Chalk dips throughout the greater 



WHITE CHALK. 13 

part of its range from west to east, the surface occupied by it is very inconsiderable com- 
pared with that of most of the other strata above and below it, but its horizontal extension 
becomes greater in proportion as the inclination of the strata diminishes. For this reason, 
from Alum Bay to Mottestone Down, and from Carisbrook to Culver Cliff, between which 
intervals the Chalk is nearly vertical, it constitutes a mere ridge of high land, which is scarcely 
a quarter of a mile broad in Aston Down ; but between Mottestone Down and Carisbrook, 
where the strata are less inclined, the width of the Chalk exceeds three miles. "^ 

" The flints in the Chalk are for the most part irregular in shape, but they sometimes 
constitute tabular layers coincident with the stratification, or else filling cracks and joints. 
Those flints which occur parallel with the bedding are of a different age from those filling 
the cracks and joints. The former are derived from siliceous matter, frequently, and 
perhaps in most instances, deposited contemporaneously with the calcareous sediment of 
which the Chalk is composed, around sponges and other organized bodies, the forms and 
internal structure of which are still preserved. The latter, on the contrary, are of more 
recent origin, having been carried by percolating water holding silica in solution into cracks 
and joints formed by the Chalk during or after its solidification. The tabular bands 
of flint filling cracks and joints are therefore, and as might be expected on the last suppo- 
sition, unfossiliferous, instead of abounding in fossils, as is the case with the other system 
of flints." " In the upper part of the Chalk, where the beds are the most highly inclined, 
the flints, which appear to be whole when viewed in sifif, are found, on closer examination, 
to be nearly all broken so that when extracted from the quarry they fall to pieces." 
" Shattered flints may be observed in the large chalk-pits south of Newport, and on Avreton 
Down ; also on Ashley Down, where the Chalk is rather hard (as is most frequently the case 
where it is inclined at a high angle), dipping G.j° in a direction slightly east of north. "^ 

The AVhite Chalk contains many species of Echinida% of which the most common are 
Ecldnocorys vul(jariH, Breyn. ; Galerites albo-t/alerus, Lamck. ; Micrasfer cor-anr/uinuhi, 
Klein ; Cidaris davi(/era, Konig ; Cidaris sceptrifcra, Mant. ; Cidaris subvesiculosa, 
d'Orbigny, and several other forms, to be figured and described in the following pages. 

The " Upper White Chalk with flints " of English authors corresponds to the Crair 
Handle of the French, the Obere Kreide of the Germans, and the Etarje Sinonicn of 
d'Orbigny. 

Besides the localities already mentioned, it is well exposed and very fossiliferous at 
Lewisham, Grays, Northfleet, Norwich, Brighton, Dover, and other places in the counties 
Sussex and Kent, and at Flamborough Head, on the Yorkshire coast. 

The following table exhibits at a glance the subdivisions of the Cretaceous formations, 
with their lithological characters, chief localities, and foreign equivalents, so as to afford 
an easy reference to the stratigraphical distribution of the species of Eddaid<B in each of 
the beds. 

1 Eristow, on the " Geology of the Isle of Wight," 'Mem. of the Geol. Suit.,' p. 28. 
^ Brislow, ibid., p. 31. 



14 



CRETACEOUS GROUP. 



A TABLE OF THE CRETACEOUS GROUP OF ENGLAND. 



SUBDIVISIONS. 



LITIIOLOGICAL CHARACTER. 



LOCALITIES. FOREIGN EQUIVALENTS. 



Upper Chalk 



o 

pi 
o 

o 
o 

Eh 

w 
Pi 
o 

H 



Lower Chalk, and 
Chalk-marl. 



Chloritic BIarl 



Upper Green sand 



Nearly pure carbonate of lime, with 
minute fragments of Shells and 
Foraminifera, forming a white or 
yellowish-white, soft Chalk ; the 
upper beds of v/hich are interstra- 
tified with laj'ers of flints, or tabu- 
lar layers of dark silex coincident 
■with the stratification. 

Hard Chalk, without flints, sometimes 
passing into Chalk-marl or hard 
Grav Chalk. 



Light-coloured marl, full of green 
specks of silicate of iron, with 
numerous fossils. 



Siliceous sand, or nearly calcareous 
sand, with grceu grains ; the rock- 
often contains nodules of chert and 
masses of limestone. 



Isle of Wight, 
Lewisham, Grays, 
Northfleet, Nor- 
wich, Brighton, 
Dover, Flam- 
borou2:h Head. 



Crate blanche, French. 
Obere Kreide, Germans. 
■ Etage Sinonien, d'Orb. 



Dover, Folkestone, 
Lewes (Sussex), 
Swafiham, Nor- 
wich. 

Chard, Chardstock, 
St. Catherine's 
Down, Isle of 
Wieht. 



TJntere Kreide,Qiexm&xis, 
. Planer, Germans. 
Craie tnffeau, French. 
Etaye Tiironien, d'Orb. 



crayeuse. 



Gault . 



'l 



Dark-blue tenacious clay, sometimes 
marly, with some concretions. 



Warminster, De- / 
vizes,ChuteFarm, 
Petersfield, Cam- 
bridge, Char- 
raouth, Dorset. 

Isle of Wight, 1 
Folkestone, Char- 
mouth. 



Glauconie 
French. 
\ Tourtia, Belgians. 
GrUnsand, Germans. 
Etage Cenomanien, d'Orb. 



Red Chalk 



A thin bed of hard, red Chalk, deeply a 

coloured by the pero.xide of iron, Hunstanton Cliflf, 
and having numerous small sili- \ -Noriolk ; riley 
ceous grains and pebbles of quartz, 1 "^y' Yorkshire. 
&c., strewed throughout the mass. 



^ Gault, Germans. 
Etage Albieii, d'Orb. 



Speeton Clay. 
[Upper part.] 



^ Lower Green sand . 



'A grayish-coloured clay, the upper 
portion containing Neocomian, tiie 
lower portion Poitlandiau species 
of fossil shells. 

A great areuacous formation, com- 
posed of ferruginous sands with 
green grains, dark-coloured clays 
and clayey sands ; and in some 
localities,bands of limestone known 
as Kentish Rag. 



Filey Bay, York- 
shire. 



Isle of White, 
Folkestone, 
Ilythe, Maid- 
stone. 



Terrain NSocomien sitpc- 
rieur of Swiss and 
French. 
Etage Aptien, d'Orb. 



ECHINODERMATA. 15 



Classification op the ECHINODERMATA. 

The name Echinodermata was given by Klein, in 1734,^ to the shells of Sea- 
iii'cliins called Echini. Brnguicre^ subsequently gave the name Echinodermata to that 
division of the animal kingdom which comprised the Star-fishes and the Sea-urchins. 
Cuvier^ included in his class Eciiinodermes, with Asferias and Echinus, the Holothitria, 
animals destitute of the prickly skin of the more typical forms, and which had many 
external affinities with some Mollusca ; and subsequently, in his ' Regno Animal,'* he 
grouped in this class les Eciiinodermes sans pieds, forming the order Sipunculida, which 
connect the Radiata with the Annulose Articulata. 

The Echinoderms are highly organized animals, for the most part covered with a 
coriaceous integument. In several orders it is strengthened with numerous calcareous 
pieces, which together form a complicated skeleton. The external sm'face of the skin, in 
many families, develops spines of various forms, which serve as instruments of defence 
or locomotion to the creatures possessing them. By far the largest number of these 
animals have a complicated system of vessels for circulating water through their bodies. 
These aquiferous canals are intimately connected with the life and motion of the animal ; 
by means of this vascular water-system most of the typical groups erect those remarkable 
suckers which protrude in rows from different divisions of the body ; in the Echinoidea 
they escape through holes in the poriferous zones, and in the Asfcroidca pass through 
apertures between the small plates forming the middle of the rays ; whilst in the Sipun- 
culida these organs are altogether absent. 

No class of the animal kingdom more clearly exhibits a gradation of structure than 
the Echinodermata ; for, whilst some remain rooted to the sea-bottom, and in this sessile con- 
dition resemble the Poli/pifera, others, clothed in prickly armom*, and exhibiting the true 
rayed forms characteristic of the central groups, conduct, through a series of beautiful 
gradations, to soft elongated organisms, whose outline mimics the Ascidian Mollusca, 
whilst others exhibit the long cylindrical body, annulose condition of the skin, and 
reptatory habits of the Apodous Annelida. 

With so fertile a field for investigation, it is not surprising that the minute anatomy 
of the Echinodermata should have engaged the attention of some of the most distinguished 
zoologists of our age, and have yielded fruits which the physiologist reckons as amongst 
the most marvellous contributions to morphological science. 

1 'Naturalia Dispositio Ecliinodermatum,' Jacobl Theodori Klein, 1/34. 

2 'Tableau Encyclopedique des trois U6gaes de la Nature," 1791. 

^ 'Tableau Elementairc de I'llistoire naturelle des Animaux,' 1798. 
* ' Rfegne Animal destiibue d'apres son Organisation,' 1834. 



16 ECHINODERMATA. 

Tlie class Ecliiiiodermata is divided into eight orders, which, in descending sequence, 
may he thus arranged : 



1. SiPCNCULOIDEA. 

2. HOLOTHUKOIDEA. 

3. EciIlNOIDEA. 

4. ASTEIIOIDEA. 



5. Ophiukoidea. 
C. Blastoidea. 

7. Cystoidea. 

8. CltlXOIDEA. 



Order I. SiruNCULOiDEA — form the apodal Annulose Echinoderms ; they have a 
long cylindrical body, divided into rings by transverse folds of the inlegument; they have 
neither tubular suckers nor calcareous parts developed in their body, nor is it divided 
into a quinary arrangement of longitudinal lobes ; some have horny booklets like the 
feet of many Annulosa, which they much resemble ; their moutli is provided with a 
retractile proboscis, and surrounded by small tentacula, differing both in structure and 
arrangement to the homologous parts in the IMothtria. In them the type of Ttadiaia 
vanishes and that of Annulosa appears. They are unknown in a fossil state. 

Type. Sipuncidus edulis, Pallas. 

Order ii. Holothuroidea. — Body in general elongated ; skin in general soft and 
leathery, in a few genera strengthened by calcareous or horny spines. Five avenues of 
suckers divide the body into as many nearly equal segments ; month surrounded by 
plumose tentacula, the numbers of which are usually multiples of five ; vent at the 
opposite extremity of the body ; digestive organs consist of a large intestine, which makes 
several coils in passing through the body ; respiration performed by internal ramified 
tubes, like a miniature tree; locomotion effected by contractions and extensions of the 
bodv, and bv rows of tubular suckers, similar to those in the Star-fishes and Sea-urchins. 
The softness of their naked integument prevents their preservation in the stratified rocks. 

Type. Cuciimaria froiuhsa, Gunner. 

Order in. Echinoidea. — Body spheroidal, oval, or depressed, enclosed in a test, 
composed of twenty columns of calcareous plates, with ten rows of holes for the passage of 
retractile tubular suckers ; the surface of the test is studded with tubercles, which have 
jointed with them moveable spines, of various sizes and forms in the different families, 
and genera ; at the summit of the test is the apical disc, composed of give genital plates, 
perforated for the passage of the ovarial and seminal tubes, and five ocular plates for 
lodging the five eyes. The mouth, situated always at the under surface, is in many 
genera armed with five powerful, complicated jaws and teeth, and in others the peris- 
tome is edentulous ; the vent occupies various different positions, sometimes within the 
apical disc and surrounded by its elementary parts, sometimes external to the disc, and 
at the upper surface, side, or base, the relative position of the vent to the disc affording 



ECIIINODERMATA. 17 

an important cliaractev for the subdivision of the order into two primary groups. The 
intestine winds rounds the shell, attached by a mesentery, the surface of which, as well as 
the membrane lining the shell, is covered with vibratile cilia. 

Type. The common Sea-urchin, Echinus sjihtera, Milller. 

The EcHiNoiDEA arc represented by one family in the Paljeozoic rocks, and by 
numerous families in the Mesozoic and 'J'ertiary groups, several of which characterize 
these great periods of geological time. They likewise abound in our present seas. 

Order iv. Asteroidea. — Body stelliform, depressed, with five or more lobes or 
hollow arms, forming a continuation thereof, and containing prolongations of the viscera; 
the mouth is always inferior and central, and the intestine often terminates in a vent 
opening at the upper surface; in some genera the vent is absent; rows of retractile 
tubular suckers occupy the ambulacral areas in the centre of the under sarftice of the 
rays. Skeleton complicated, composed of numerous solid calcareous pieces, variable as to 
number, size, and disposition ; skin coriaceous, studded with calcareous spines of various 
forms ; a madreporiform plate on the upper surface, near the angle between two rays ; 
eyes placed at the extremity of the rays ; reptation performed by tubular suckers. 

Type. The common Star-fish, Urastcr rubetis, Linn. 

This order is represented in the Silurian rocks by several genera. The Oolitic, Cre- 
taceous, and Tertiary rocks contain many extinct forms. The existing species are very 
abundant in all our present seas. 

Order v. Ophiuroidea. — Bpdy discoidal, distinct, depressed, provided with long, 
slender arms, in which there is no excavation nor prolongation of the viscera; they 
are special organs of locomotion, independent of the visceral cavity, and have spines, 
and membranous tentacula developed from their sides ; mouth always below and central, 
serving at the same time as the vent. Skeleton complicated, composed of calcareous 
pieces, of which the size and number varies in different genera. Their long, slender rays 
are supported internally on a framework of central vertebra-like pieces ; they form special 
organs of locomotion, independent of the visceral cavity, and numerous plates and spines 
are regularly disposed along their sides to assist in reptation. 

Type. The common Sand-star, Ophiura lewturafa, Lamarck. 

This order is represented by one genus in the Silurian, and several genera are 
found in the Oolitic, Cretaceous, and Tertiary rocks, as well as in our present seas. 

Order vi. Blastoidea. — Body in the form of an oval calyx, composed of solid, 
calcareous plates, provided with five inter-ambulacra and five ambulacra, the latter united 
superiorly, striated transversely, and having a deep furrow down the middle ; ten ovarial 
holes, opening into five at the summit, M-ith a central oral aperture, a short, slender 
stem, and the body destitute of arnis. 

3 



18 ECHINODERMATA. 

Type. Peiiirciniles injlatus, Sow. Carboniferous Limestone. 

Tlie genera are all extinct, and belong to the Palseozoic rocks. One species appertains 
to the Upper Silurian, six to the Devonian, and twenty-four are special to the Car- 
boniferous rocks. 

Order vii. Cystoidea. — Body more or less spherical, supported on a jointed stem ; 
the bursiform calyx is formed of close-fitting polygonal plates, varying in number in the 
different genera, and investing the surface like a coat of mail, except above, where there 
are three openings, one for the mouth, one for the vent, and one with a valve for the 
reproductive organs ; the fourth aperture is below, and continuous with the canal in 
the stem. Some have two or four arms, others are armless; certain forms possess arti- 
culated tentacula and curious comb-like appendages, or pectinated rhombs, in connection 
with the plates. 

Type. Pseudocrinifes qvadrifasciafiis, Pearce. Upper Silurian. 

This order is extinct. All the genera are found in the Silurian and Devonian rocks. 

Order a'iii. Crinoidea. — Body fusiform, distinct, formed of a calyx composed of a 
definite number of plates, provided with five solid arms, independent of the visceral 
cavity, and adapted for prehension; mouth and vent distinct; no retractile suckers; 
ovaries at the base of the arms opening into special apertures. Skeleton complicated, 
calcareous, composed of thick plates closely articulated together ; their number 
and arrangement are determinate in the different families, the multiples of five being 
those which predominate ; the central plate of the .body is supported on a long, 
jointed column, that was firmly rooted to the sea-bottom. The mouth is central, and 
prominent; the vent is situated at its side; the arms are mostly ramose and multi- 
articulate, and when extended formed a net-like instrument of considerable dimensions. 
The mouth is always placed upwards, and retained so by the column being jointed to the 
central plate of the calyx. The normal station of the Crinoidea is the reverse of the 

ASTEROIDEA and ECHINOIDEA. 

Type. Pentacrinus Caput-Medusce, Miller. From the seas of the Antilles. 
Extinct families of Crinoids have lived in all seas from the Silurian upwards, and 
only one or two representatives now exist. 

From the above analysis of the class Echinoderjiata, it appears that, as the Sipuncu- 
loidea and Hohfhuroidea are not found in a fossil state, and the Blastoidea and Cystoidea 
are special to the Palaeozoic rocks, our field of investigation in this Monograph is limited 
to the EcHiNOiDEA, AsTEROiDEA, OpHiuROiDEA, and Crinoidea, which we now propose 
to consider seriatim, commencing with the Echinoidea. 



ECHINOIDEA. 19 



Order — Echinoidea. 



Tlie body is spheroidal, oval, depressed or discoidal, and enclosed in a calcareous 
test or shell, composed of ten columns of large plates, Ihe inter-ambulacral areas, and ten 
columns of small plates, the amhulacral areas, separated from each other by ten rows of 
holesj the poriferous zones. The external surface of the plates is studded with tubercles 
of various sizes, in the different families ; to these the spines are moveably articulated by 
ball-and-socket joints; the spines are of various forms and dimensions, and serve well to 
characterize the species. 

At the summit of the test is the apical disc, composed of five genital plates, perforated 
for the passage of the ovarial and seminal canals, and five ocular plates, notched or 
perforated for lodging the eyes. There are two great openings in the test, one for the 
mouth and the other for the vent ; the relative position of these apertures varies in different 
families, and forms an important character in their systematic classification. 

The mouth in some families is armed with a complicated apparatus of jaws and teeth, 
in others it is edentulous. The internal organs of digestion consist of a pharynx, 
oesophagus, stomach, and intestine, which winds round the interior of the test, attached 
thereto by a delicate mesentery; its surface, as well as the lining membrane of the 
shell, is covered with vibratile cilia ; these cause currents of water to traverse the 
interior of the body, and perform an important part in the function of respiration ; 
the blood is circulated in arteries and veins, aided by a central pulsating organ or heart. 
The five ovaries and testicles occupy the ambulacral divisions, and open externally through 
holes in the genital plates. Locomotion is performed by the joint action of .the 
tubular retractile suckers and the spines. Many sea-urchins attach themselves to rocks 
by their tubular feet, and some bury themselves in limestone and sandstone, or even 
granitic rocks, by the abrading action of the spines. 

The nervous system consists, according to M. Van Beneden, of a circular cord, which 
surrounds the entrance to the digestive organs, and sends branches into the divisions of 
the body. Professor Agassiz, and the late Professor Edward Eorbes, regarded the organs 
situated in the ocular plates as eyes, but M. Dujardin^ denies them even a nervous 
system. In the absence of more direct anatomical evidence on the point, the following 
observation, related by M. Alcide d'Orbigny," has an important bearing on the question, 
and supports it affirmatively : 

Captain Ferdinand de Cande, who commanded the ' Clcopatre' in the Chinese seas, 
told M. d'Orbigny that he had captured, on the coast of that region, an urchin with long 
spines, probably a Diadtma, which he examined in a vessel of water, "I hastened to 

1 Lamarck, ' Animaux sans Vertebres,' 2nd ed., torn, iii, p. 200. 

2 ' Paleontologie Fran9aise, Terrain Cretace,' torn. y\, p. 12. 



20 ECHINOIDEA. 

seize it," he observed, " when it instantly turned all its spines in the direction of my 
hand, as if to defend itself. 

" Surprised at this manoeuvre, I made an attempt to seize it on the other side, when 
immediately the spines were directed towards" me. 

" I thought from this that the urchin saw me, and that the motion of the spines was 
intended as an act of self-defence ; but, to prove whether the movement of the animal 
was produced by my approach, or merely by the agitation of the water, I repeated the 
experiment very slowh^, and even over the water with a stick. The urchin, whether in 
the water or out of it, having always directed its defensive spines towards the object which 
approached it. From these observations I arrived at the conclusion that these urchins 
see, and that their spines serve them as defensive instruments." 

It is worthy of remark, that Captain Cande, at the time he watched this urchin, was 
ignorant of the anatomical fact that eyes had been detected in the Echinidae, and his 
inference was the conclusion drawn from carefully made observations. 

The calcareous test of the Echinoidea is the only part of the structure of these animals 
preserved in a fossil state. It has hitherto failed to attract that amount of atten- 
tion from the palaeontologist which the importance of its study demands ; although in a 
stratigraphical point of view this skeleton is not inferior to that of any other class of the 
Animal Kingdom. The fact seems to have been almost entirely overlooked by paltcon- 
tologists, that most of the generic characters of the different groups of Echinidce are more 
indelibly impressed on the separate pieces of their test than in the skeletons of any other 
class of the Invertebrata. 

Unlike the shells of the Mollusca, the test of the Echinoidea constitutes an internal and 
integral portion of the animal, being secreted by, and enclosed within, organized mem- 
branes, it participates in the life of the organism, and certain parts of the skeleton are 
intimately connected with the organs of digestion, respiration, and generation, as well as 
with those of vision and locomotion. 

As it is intended to give an analysis of the test of the Echinoidea, M'itli anatomical 
details of the structure of the skeleton in the Echinodermata in general, in the General 
Introduction to these Monographs, it is at present unnecessary to enter minutely into the 
subject ; but, as many of our readers are doubtless unacquainted with the terminology 
employed in the description of the test, and the characters on which a diagnosis of the 
species is made, it is desirable now to preface our description with brief explanations of 
the same, illustrating the terminology by a reference to the plates for accurate figures of 
different parts of the test, and magnified details of the anatomical characters thereof.^ 

' In connection with the physiology of the Echinodermata, the following discovery, made by Dr. 
WalHch, i.s most important : 

"Thirteen living star-fishes, differing in no important particular from a species common on our own 
and most northern coasts, were brought up from a depth of 12G0 fathoms, or very nearly a mile and a 
half, at a point midway between the southern extremity of Greenland and Ttocknll, and 250 miles distant 
from ih.e nearest land. Tiiesc star-fishes, however, cnnnot be said to have been captured by the sounding- 



TERMINOLOGY. 21 

TERT^IINOLOGY, 

Or a descriptive analysis of the comjioiici)f elements of the test of the Echinoidea. 

The test of the Echinoidea is composed of tlie following parts : 

a. Five ambulacral areas. 

b. Five inter-ambulacral areas. 

c. Ten poriferous zones. 

d. Vent- opening and anal plates. 

e. Month-opening, peristome, buccal membrane and plates. 
/. Five jaws when organs of mastication exist. 

(/. Tubercles of various sizes, developed from the outer surface of the plates. 
//. Spines of different forms and dimensions, jointed with the tubercles. 

These are the essential parts to be known ; others, of secondar}^ importance, will be 
described in their proper place in the Monograph. 

The hodt/of the Echinoidea is divisible into three parts : — 1st. The calcareous envelope, 
or skeleton, which has a globular, circular, oval, pentagonal, hemispherical, conoidal, or 
discoidal form, and is composed of a framework of hexagonal, pentagonal, or polygonal 
calcareous plates. This testaceous box is called the test; it is the/o/w, the test, of 
Agassiz ; the (jeneral form, the test, of Desmoulins ; h coquitle, d'Orbigny. 

machine, for they came up adhering by their spine-covered arms to the last fifty fathoms of the sounding- 
line, not as voluntary exiles from below, but owing to their having coiled themselves around a material 
from which they found it impossible afterwards to disengage themselves. Now, apart from all other 
evidence, the facts in connection with this particular sounding were sufficient to indicate that the star- 
fishes had been raised from the sea-bed itself, and had not grasped the line whilst floating in some stratum 
of water intermediate between it and the surface. But, by a singular piece of good fortune, the question 
as to their last resting-place admitted of definite determination on evidence that they bore along with 
them. To comprehend the value of this, it is necessary to mention that, by means of a separate observa- 
tion taken upon the same spot, the bottom was found to consist almost entirely of the minute shell-covered 
organisms (Foraminifera) already referred to ; and faking into consideration the fact that many of the shells 
were completely filled with the gelatinous substance of which their bodies are composed, and, lastly, the fresh 
appearance of this substance, the probability is very great that they, in common with the star-fishes, had 
lived and multiplied at the bottom. But the only circumstance which ought to be accepted as direct proof 
of their vitality, namely, motion after reaching the surface, was wanting ; as it well might be, since 
the passage through the vertical mile and a half of water occupied nearly an hour, and the change of 
conditions to which the creatures became subjected during that period must necessarily have been very 
great. Nevertheless, the chain of circumstantial evidence was rendered complete ; for, on examining the 
stomachs of the star-fishes, they were found to contain the minute shelled creatures in abundance, thus 
clearly establishing the fact of the star-fishes having attached themselves to the sounding-line whilst it 
rested on the bottom, and adding the strongest confirmation to the view that the minute creatures referred 
to were brought up from their natural habitation." (Dr. Wallich, " On the Deep-Sea-Bed of the Atlantic, and 
its Inhabitants;" ' Quarterly Journal of Science,' No. 1, p. 40.) 



22 ECHINOIDEA. 

2nd. The visceral cavity, containing the organs of digestion, respiration, circulation, 
and generation, is formed entirely by the interior of the test. 

3rd. The external surface of the test is covered with spines, which are moveal^ly 
articulated, with the tubercles seen on the surface. 

The normal position of the hody. — In describing the different parts of the test of the 
Echinoidea, it is assumed that an urchin, the common purple heart-urchin, Sjjatangus 
purpureus, Miiller,^ for example, is placed before the observer. The side with the single 
ambulacrum lodged in the anteal sulcus, and the mouth in that third of the base, is the 
anterior ret/ion. The side having the single inter-ambulacrum in the middle and the vent- 
opening in the upper part of the border is the posterior region. The four other ambu- 
lacra are disposed in pairs, and correspond to the right and left sides of the observer's 
body ; there is, therefore, a right antero-lateral and a right postero-lateral, a left antero- 
lateral and left postero-lateral, ambulacral area. The four other inter-ambulacra, besides 
the single one in which the vent is situated, are likewise disposed in pairs, two of 
these, with the single ambulacrum, forming the anterior part, the other pair, with the 
pairs of ambulacra, the sides, and the single inter-ambulacrum the posterior part of 
the test. 

All Echinoidea3 have the mouth situated at the under side of the body ; the surface in 
which the opening is placed is the base, that region of the test opposite the base is the 
up2)er or dorsal surface. 

The most convex part of the margin, border, or sides, between the base and upper 
surface, is the circumference, or ambitus of some authors ; it is round, flat, convex, angular, 
or carinated, according to the general form and thickness of the test. 

The length or antero-posterior diameter is the distance between the anterior and 
posterior regions, and corresponds to the middle line of the body. 

The breadth or transverse diameter is the distance between the greatest lateral 
convexity of the circumference in the direction of a line cutting the line of length at 
right angles. 

The height is the distance between the most convex part of the upper surface and the 
plane on which the base of the test rests. The apical disc is generally situated at the 
vertex, but it is not always so ; the height has always reference to the highest point of the 
test, quite irrespective of any other consideration. The test has invariably two openings, 
one for the mouth, the other for the vent. 

The mouth-opening is always situated at the under surface ; to its circumference is 
attached the buccal membrane, and through the central aperture thereof protrudes the 
five jaws (PL V, fig. 1 ; PI. VII, fig. 1) ; when they exist, the buccal, like the anal mem- 
brane in many families, is clothed with numerous small plates. 

In the Cidaris, Rabdocidaris, Goniocidaris, Diplocidaris, and probably in all other 

' Tlie common Chalk-urchin Miraster cor-anginum, Klein, -will answer equally well. 



TERMINOLOGY. 23 

Cidaridce, the mouth-opening is central, circular, or slightly pentagonal (PI. IV, fig. 16) ; 
but in Hcmicidaris, Pseudodiadema, Ilemipcduia, Pedina, Echinus, and other Echi?iideB, the 
mouth-opening is more or less decagonal, its margin being divided by notches {eniaiUes) 
into ten lobes ; the lobes, in general, are unequal in size, those corresponding to the 
base of the ambulacra being the largest ; they are called the amhilacral lobes ; corre- 
sponding to the base of the inter-ambulacra are the inter-ambulacral lobes. The margin of 
the mouth-opening is called the j-jc^mYo^wc, to it the buccal membrane which closes the 
base of the test is attached. 

The mouth-openinf/ is central and armed with jaws in the Cidarid.e, Echinid/E, 
Salenid^, Gai.eritid^, and Clypeasterid^. It is more or less excentral and edentulous 
in the Echinonid^, Collyritid^, EchinolampidjE, EchinocorydjE, and Spatangid^; 
in them it is round, oval, or pentagonal; sometimes its margin is ring-like, or surrounded 
by five prominent lobes ; in others it is distinctly bilabiate. 

The ve)it, or anal oj)ening, is always in the upper surface, in the centre of the genital 
and ocular plates, directly opposite to the mouth, and is either central or subcentral in 
the CiDARiDiE, EcHiNiDiE, and Salenid^ (PI. VI, fig. 1). In other families its position 
varies much ; sometimes it opens on the upper surface, as in some Galeritid^ and 
Cassidtjlid^. Sometimes it opens on the margin or is siqyra-marglnal, marginal or 
infra-marff'uial; often it opens at the base between the mouth and the border. During the 
life of the animal this opening is closed by an anal membrane and a series of small angular 
anal plates ; their number and disposition varies in the different genera. The anal plates 
are seldom preserved in fossil species, and the term anal opening is given to all that part 
of the test occupied by them and the vent. PI. VI, fig. 1 a, is a magnificent specimen of 
Cidaris scejjlrifera, Mant., belonging to the British Museum, in which the anal plates are 
finely preserved in situ. 

The Ambulacral and Inter-ambidacral Areas. 

The test is composed, 1st, of twenty columns of calcareous plates of different sizes, the 
plaquettes, Tdfekhen, Assulce of authors ; they are pentagonal in form, and united by 
harmonial sutures to form rays, which proceed from the mouth, where they have their 
greatest breadth, to the apical disc, where they are narrowest. 2nd. Of a series of hexagonal 
or polygonal plates, forming a disc, which occupies the upper surface of the test. 3rd. Of 
ten rows of small plates, notched on their margins to form holes; these form the 
poriferous zones. 4th. Of moveable spines, that are jointed with eminences on the outer 
Surface of the columnar plates. 

The ambulacral plates form two narrow columns, which are bounded by two poriferous 
zones. The space thus circumscribed is the ambulacral area. There are five of these areas 
in the test of the Echinoidea. In the Cidarid^ the ambulacral areas are very narrow, 
and support only granules (PI. VI, fig. 1, a, b, c, d). In the Echinid^, they are much 



24 ECHINOIDEA. 

wider, and liave large tubercles on their surface. The comparative width of the ambulacra 
as compared with the inter-ambulacra has led some authors ^ to divide the family Cidnrldcc, 
including therein the EchinUhe, into two tribes, the Angustistell.^, or Cidaridse with 
narrow ambulacra, and the Latistell^e, or Cidarida^ with broad ambulacra. These two 
tribes nearly represent our two families ; the Cidarid.e are equal to the Angustistell.e, 
and the Echinid^ are nearly equal to the Latistell^e. 

One of the ambulacral areas is single, and always represents the anterior region in the 
spheroidal Ecldnkla: and Bulcnidce. 'Jliis is detected by its relation to the apical disc, 
as the right antero-lateral plate always carries the madreporiform body; in the oval, 
pentagonal, or elongated forms, its position and relation to the mouth renders it unmis- 
takeable. The four other ambulacra are disposed in pairs. 

The iuter-amhvJacrul jiiates form two broad columns, composing the inter-ambulacral 
areas ; of these, like the ambulacral, there are five, which alternate with them in the archi- 
tecture of the test. The poriferous zones form the line of demarcation between these two 
classes of columnar plates. The plates are all pentagonal, and many times larger than 
the ambulacral ; they carry on their surface the large primary tubercles. Of the five inter- 
ambulacral areas, one is single and posterior, and in all the Echinoidese which have the anal 
opening external to the apical disc it is in the single inter-ambulacrum that the vent ter- 
minates. The other four inter-ambulacra are disposed in pairs, and form the greater 
part of the anterior and lateral parts of the test ; they are the anterior pairs and poitcrior 
pairs, respectively, to distinguish them from the odd area, which is the siri^le inter- 
ambulacrum. 

PI. VI, fig. 1, shows the form and structure of the inter-ambulacra in the CidaridcB. 

In the Cidaridce the inter-ambulacral areas have only two rows of primary tubercles ; 
but in many of the Echinida' there are four, six, eight, or ten rows of primary tubercles 
in these areas. 

Tlie Poriferous Zones. 

Tlie poriferous zones are situated on each side of the ambulacral areas (PI. VI, fig. 1) ; 
they are composed of a very great number of small pieces, articulated together in such a 
manner as to form a series of holes. The corresponding edges of the plates remaining 
rnicalcified, at certain definite intervals produce foramina, which are destined for the 
passage of retractile tubular suckers. The form and structure of the poriferous zones form 
a good generic character. As there are two poriferous zones bordering each ambulacral 
area, it follows that there are ten zones. Some authors give the collective name ambulacra 
to the zones and the area; but for obvious reasons, I consider them distinct sections of 
the test, and treat them as such. 

1 Albin Gras, 'Description dcs Oursiiis Fossiles du depaiteuieut de I'lsere,' p. 20. E. Dt'sor, 'Synopsis 
ties Ecliinides Fossiles,' p. 2C. 



ter:minology. 25 

The pores are round, oblong, or elongated ; the pores forming a pair may be equal or 
unequal ; in relation to each other, they raay be transverse or oblique, contiguous or 
remote, and when united by a transverse sulcus they are said to be conjugate. 

The pores are differently arranged in the zones in the different families : when they are 
disposed in single pairs, they are said to be unigeminal (PI. VI, fig. 1, d); when in double 
pairs, bigeminal ; when in triple oblique pairs, trigeminal ; and when grouped in a greatei' 
number, as in many living species of the genus Echinus, they are polygeminal . 

When the zones extend in a straight uninterrupted line from the mouth to the apical 
disc, they are said to be simjile, as in the Cidarida, Echiiiidte, Salenida, Galerilida, 
EchinonidcB ; when the zones, after parting from the apical disc, expand, and again 
contract, thereby forming a leaf-like figure on the upper surface of the test, they are said 
to be pefaloidal, as in the ClypeasteridcB ; wlien the petal is not so complete, as in the 
CassidulidcB, it is subpetaloidal. The zones are complete when they extend without inter- 
ruption from the mouth to the disc ; they are interrupted when they terminate on the 
upper surface, and reappear again at the base near the mouth ; they are limited when 
they form only a star on the dorsal surface. These terms represent generic characters 
of greater or less value, and require to be carefully noted in the description of the 
species. 



17ie Apical or Genital Disc. 

The apical disc occupies the centre of the summit of the test, and is composed in 
most genera of ten plates, namely, five genital plates and five ocular plates (PI. VI, 
fig. 1, «). In the Salenidce there is one or more additional plates introduced. The five 
genital or oviductal plates correspond to the sunnnits of the inter-ambulacral areas ; two 
plates form an antero-lateral pair, two a postero-lateral pair, and the single plate is 
placed behind. On the right antero-lateral genital plate (PI. VI, fig. 1, a) is a spongy, 
prominent mass, called the madreporiform body ; the plate supporting this body was 
supposed by Agassiz and Desor always to represent the posterior part of the test, but I 
have shown that it is invariably placed on the right antero-lateral plate. 

The ocular plates are at the summit of the ambulacral areas ; they are small, heart- 
shaped bodies (PI. VIII, fig. 4, b), wedged into the angles of the genital plates around 
the circumference of the disc. 

The suranal plates are found only in the Salunid^; they consist of one or many 
elements placed in the centre of the genital circle, and always before the anal 
opening. 

The anal plates (PI. VIII, fig. 4, b), are very small bodies, and variable as to number ; 
they clothe the membrane of the anal opening, and are well seen in recent urchins ; but 

4 



26 ECHINOIDEA. 

are seldom preserved in fossil species ; they are admirably shown, however, in the fine 
specimen of Cidaris subvesiculosa (PI. VIII, fig. 4), from the collection of our kind 
friend, Dr. Bowerbank, F.R.S. 



The Tnherchs. 

The plates composing the test of the Cidaridx, Echimdce, and Salenidce, have 
large tubercles developed on their surface; they are divided mia primary tubercles, semi- 
tubercles, secondary tubercles, minute tubercles, granules, and miliary granulation. In the 
other families the tubercles are smaller, more numerous, and less complicated. 

The primary tubercles form two rows in the inter-ambulacral areas of the Cidaridce, 
(PI. I and II), and four, six, eight, ten, or twelve rows in many Echinida. 

The semi-tubercles are found at the base of the ambulacral areas of the genus Hemi- 
cidaris. In a section of the genus Hemipedina they likewise are found at the base of the 
ambulacra. 

The secondary tubercles are found in many of the EcTiinidee, ranged, in general, on the 
ambulacral side of the primary tubercles. They are found likewise on the centro-sutural 
side of the primary rows of many Pseudodiademu, Pedina, Hemipedina, and Echinus. 

The minute tubercles are the small tubercles found on the margins of the ambulacral 
areas of the genus Cidaris (PI. VIII, fig. 1) ; and they sometimes fill up spaces at the base 
of the inter-ambulacral areas. In sonae Pseudodiademata they are raised on Tittle 
eminences, and perforated like the secondary and primary tubercles. In this respect 
they are distinguished from the granules. 

The granules are small, round, hemispherical elevations, scattered more or less regularly 
over diftei-ent parts of the plates of the test. In some species of the genus Cidaris they 
are arranged in rows in the centre of the ambulacral areas, or form circles around the 
circumference of the areolas of the primary tubercles (PL VIII). 

The miliary granulation is formed by a number of small granules closely set together 
in the centre of the ambulacra, or on the inter-tubercular surface of the large plates 
composing the inter-ambulacra (PI. VIII, fig. 1). 

The priniai'y tubercles of the genera Cidaris, Hemicidaris, Psevdodiadema, 
Hemipedina, Pedina, &c., consist of the following parts : 

The hemispherical tubercle, or mamelon, is sometimes perforated in the centre, some- 
times imperforate, as in many Echinidce (PI. VII, fig. 3 r). 

Tlie loss, or mauimillary eminence, is tlie conical prominence on the surface of the 
tubercular plate ; its summit supports the tubercle, and the margin thereof is crenulated 
in Hemicidaris and Pseudodiadema, and smooth in Hemipedina and Pedina. 

These characters are important for generic distinctions. 



TERMINOLOGY. 27 

The areola, or scrobicule (PI. VI, fig. 1, d), is the round, oval, or eUiptical, smooth, 
excavated space which surrounds the base of the boss. This space is sometimes narrow, 
and its margin elevated into a ridge, that completely encircles it, when the scrobicule 
or areolar circle is said to be complete ; if the upper and under sides of the circle are 
wanting, it is incomplete, and the areolas are then said to be confluent. 

The row of granules encircling the areolas is called the areolar or scrobicular 
circle. 

The miliary zone is the space comprised between two ranges of primary tubercles, 
it is in general covered with a close-set granulation ; Avhen destitute of miliary 
granules, it is said to be naked ; the ambulacral and inter-ambulacral miliary zones 
occupy these different regions of the shell. 

When the granules are microscopic, and closely clustered together within certain 
narrow, circumscribed bands, or fascioles, intersecting the general tubercular surface, and 
occupying fixed positions on the test, they are ceiWed fasciolar. 

Fascioles are only found in two families, in one genus of the Echinocoridee, and in 
almost all the genera of the Spatanc/idce. The form, width, structure, and position of these 
bands must be carefully noted, as they afford important characters, both positive and 
negative, for the diagnosis of the genera. 

When a fascicle surrounds the circumference of all the petaloidal portions of the am- 
bulacral areas, it 1% peripetalous ; if it encircles the single ambulacrum alone, it is internal ; 
when it extends along the flanks, it is lateral ; if it passes in whole, or in part, along 
the circumference, it is marginal ; and when it surrounds the base of the single inter- 
ambulacrura, it is suhanal. Sometimes there is only one., sometimes there are two or 
three, of these fascioles in different genera. 

Each family has a special arrangement of the tubercles, granules, and fascioles ; a 
detailed account of these will be found in the general outline of the structural characters 
prefixed to the description of each natural group. 

The sutural impressions are the lines along which the plates are united together ; some- 
times they are mere lines ; or the impressions amount to excavations out of the borders 
of the plates, and give rise to cavities therein, as in the genus Temnopleurus. 

The angular or sutural pores are small impressions, situated in some genera at the 
angles of the plates, upon the median line of the miliary zones. 



The external Appendages of the Test. 

The spines, or radioles, as they were called by Plott, Lang, and other old authors, are the 
calcareous appendages that are moveably articulated to the tubercles of the test ; they 
present numerous modifications as to size, form, and sculpture, which are all intimately 



28 ECHIXOIDEA. 

connected with specific characters ; some are shorter elongated, flattened, cylindrical, fusi- 
form, or subulate ; others are compressed, spatuliforra, or triangular ; others, on the contrary, 
are expanded, pyriform, or claviform. The surface of the spines is smooth or striated with 
fine or coarse longitudinal lines ; some have verticillate processes at regular intervals, others 
have asperities, prickles, or granules, disposed with more or less regularity over the surface. 
The different parts of the spine have received the following names : 

'J'he articular cavity, or acetabulum, is the socket by which the spine articulates with the 
tubercle ; its margin is smooth orcrenulated, according as the summit of the boss is smooth 
or crenulated (PI. VI and VII) ; in all the genera with perforated tubercles there is 
a corresponding pit in the socket of the spine, for the attachment of the round ligament 
which passes from the tubercle to the spine. 

The head is that part of the spine containing the articulating cavity, and is united to 
the stem near the necl^ (PI. VII, fig. 4). 

The milled riiiff surrounds the head ; it is a prominent ridge, more or less deeply 
crenulated, around which the muscular fibres that move the spine are firmly attached. 

The neck is the smooth space between the line of jiuiction above the milled ring and 
the rugose body of the spine (PI. VII and VIII). In long, slender, tapering spines, it is 
often finely striated with longitudinal lines, and cannot be distinguished from the body into 
wliich it jiasses. 

The stem or boch/ of the ftpiiie is the part that exhibits the greatest variety of forms, 
smooth and muricated varieties are figured in PI. I, II, IV. 

The organs of mastication forming " the lantern of Aristotle " are rarely preserved in 
fossil species; they consist of five jaws, each carrying a long tooth (PI. V and VII). As 
these parts form a complicated mechanism, their analysis and description wall be given at 
length in the anatomical part of the introduction. 



On tite relative value of the e.rternal organs in the classification of the Echinoidea. 

The mouth is always basal, central, subcenti'al, or excentral, but the excentricity is 
invariably towards the anterior border. This opening does not, therefore, afford a charac- 
ter of primary importance, although, in connection with others, it is valuable in the definition 
of families. The month is .«ometimes armed with jaws, but it is oftener edentulous. 

The position of the anal opening affords a character of primary importance. In one great 
section the vent opens icithin the centre of the apical disc, surrounded by the genital and 
ocular plates. The relation, therefore, of the digestive organs to those of generation and 
\ision, is an important primary character for the zoologist. In another section the vent 
opening is without the apical disc, and is more or less external to, and at a greater or less 
distance from, the genital and ocular plates. The physiological importance of the external 
relation of the organs of digestion, generation, and vision, to each other, imparts great 



CLASSIFICATION. 29 



A 



alue to the position of the anal opening ; and hence it forms the basis of the subdivision 
of this order into two sections, which are thus defined : 



EcJdnoidea endocydica. 

A. Test circular, spheroidal, more or less depressed, rarely oblong ; mouth in the centre 
of the base. Vent in the centre of the upper surface, directly opposite to the 
mouth, surrounded by five perforated genital plates, and having external to them 
five ocular plates. Mouth always armed with five powerful calcareous jaws, formed 
of many elements, disposed in a vertical direction. 



Echinoidea exocyclica. 

B. Test sometimes circular and hemispherical ; ofteuer oblong, pentagonal, depressed, 
clypeiforra, or discoidal ; mouth central or ex-central. Vent external to the circle 
of genital and ocular plates, never opposite the month, and situated in different 
positions in relation to that opening : four of the genital plates are generally 
perforated. The mouth is sometimes armed with five jaws, oftener it is 
edentulous. The elements of the lantern are disposed in a more or less horizontal 
.direction. 

The structure of the ambulacral areas, and poriferous zones, afford good characters 
of secondary importance for grouping the genera into natural families, especially when 
taken in connection with the position of the vent, which varies in its relation to that of 
the mouth-opening in different families. 

The form, number, and arrangement of the tubercles, and the spines that are jointed 
with them ; the miliary granulation ; the bands of microscopic granules forming the fas- 
cioles, having permanent positions on the test ; also the size and number of the 
elements of the apical disc, and the position of the vent, afford collectively good characters 
for defining the genera. 

The minute details of the structure of the plates ; the form, size, and number of the 
tubercles on each of them ; the arrangement of the pores, their proximity or remoteness 
from each other in the zones ; the general outline of the test, which has only certain 
limits of variation ; the form of the areolas; the presence, absence, size, and distribution, 
of the granules forming the scrobicular circle ; the completeness or incompleteness of the 
same ; the length of the spines, their form and sculpture, are points affording good specific 
characters, as they are persistent details that are developed on every considerable fragment 
of the test and spines of the Echinoideae. 



30 



ECHINOIDEA. 



Taking these general principles for my guidance, I subdivide the Echinoidea into 



the followins: thirteen natural families 



Order— ECamOlDE A. { 



Echinoidea endocyclica. 

Vent within the genital plates, 
always opposite the mouth. 



Echinoidea exocyclica. 

Vent without the genital plates, 
never opposite the mouth. 



Cidaridse. 

Hemicidaridse. 

Diademadse. 

Echinidae. 

Salenidse. 

Echinocouidse. 

Collyritidse. 

Echinonidse. 

Echinobrissidse. 

Echinolampidae. 

Clypeasteridse. 

Echinocoridse. 

Spatangidse. 



Famili/ \. Cidarid^. — ^Test thick, spheroidal; iiiter-ambulacral areas very wide; 
primary tubercles large, perforated ; bosses crenulated or uncrenulated, spines large, 
thick, mostly claviform ; ambidacral areas very narrow ; poriferous zones narrow, pores 
nnigeminal, rarely bigeminal ; mouth-opening large, inferior, central, circular or penta- 
gonal ; peristome destitute of notches, always armed with large, powerful jaws. Vent- 
opening wide, superior, opposite the mouth, surrounded by five large genital plates 
perforated for the ovarial canals, and five small ocular plates excavated for lodging the 
eyes ; buccal and anal membranes covered with scales. 

Types. Cidaris clavigera, Ktinig (PI. IV). Cidaris scepfrifera, Mantell (PI. VI). 

Family 2. Hemicidarid^. — Test thick, spheroidal, or more or less depressed ; ambu- 
lacral areas narrow or wide, with semi-tubercles at their base only, or extended throughout 
the area ; inter-ambulacral areas with two rows of primary tubercles, rarely more than 
eight in each row ; tubercles of both areas perforated, and bosses deeply crenulated ; 
poriferous zones narrow and undulated ; pores unigeminal throughout, except near 
the peristome, where they are bigeminal and trigeminal. Mouth-opening large ; peristome 
decagonal, and divided more or less deeply by notches into ten lobes ; jaws large and 
powerful ; apical disc small, opposite the mouth, composed of five genital and five 
ocular plates. Spines long, thick, cylindrical, tapering, claviform, or stout, compressed, 
or angular; surface smooth, or covered with fine longitudinal lines, as far as known, 
neither prickles nor asperities are developed thereon. 

Types. Hemicidar is intermedia, Fleming. Acrocidaris formosa, Agassiz. 



Family 3. Diademad^. — Test thin, circular, or pentagonal, more or less depressed ; 



CLASSIFICATION. 31 

aiiibulacral areas wide, with two or foiu' rows of primary tubercles ; inter-ambulacral areas 
with two, four, six, or more rows of tubercles, nearly of the same size and structure as 
those of the ambulacra; tubercles perforated or imperforated, crenulated or uncrenu- 
lated, in different genera ; apical disc small, opposite the mouth, composed of 
five genital and five ocular plates ; poriferous zones narrow ; pores unigeminal or 
bigeminal. Mouth-opening large and decagonal ; peristome divided into ten lobes by 
deep notches ; spines long, cylindrical, more or less slender, either tubular or solid ; 
sometimes encircled by spiral verticillate processes, or their surface is sculptured with fine 
longitudinal lines. 

Types. Astropyga radiata, Leske. Cyphosoma Kcenigii, Mantell. Pseudodiadema 
tumidi/iH, Forb. 

Family 4. Echinid.e. — Test thin, spheroidal ; inter-ambulacral areas, with small 
primary tubercles, of various sizes, perforate or imperforate; bosses crenulate or un- 
crenulate ; ambiilacral areas wide, always supporting two or more rows of primary 
tubercles ; poriferous zones narrow or wide, pores unigeminal, trigeminal, or polygeminal, 
and disposed in arcs ; spines short, mostly subulate. Mouth-opening large, inferior, 
always decagonal ; peristome divided into lobes by notches more or less deep. Vent 
small, superior, opposite the mouth, surrounded by five genital and five ocular plates ; 
buccal membrane naked. 

Types. Echinus sphcera, Miiller. Codiopsis Donia, Desmarest. 

Family 5. Salenid^. — Test thin, spheroidal; inter-ambulacral areas wide, with few 
primary tubercles, either perforate or imperforate, crenulate or uncrenulate ; ambulacral 
areas narrow, carrying secondary tubercles. Mouth-opening small or large, inferior, 
decagonal ; peristome more or less notched. Vent superior, surrounded by the plates of 
a large apical disc, composed of more than ten pieces, occupying a wide aperture in the 
superior part of the test. Poriferous zones narrow, pores unigeminal, except near the 
peristome, where they are trigeminal. Spines long, subulate, circular, or flattened. 
Species all extinct ; the genera distributed in the Oolitic, Cretaceous, and Tertiary 
rocks. 

Types. Salenia peialifera, Defrance. Acrosalenia hemicidaroides, Wright. Gonio- 
phorus lunidatus, Agassiz. Hyposalenia Wrigldii, Desor. 

Family 6. EchinoconiDjE. — Test thin, circular, elongated or pentagonal, elevated or 
depressed ; inter-ambulacral areas wide, ambulacral areas narrow ; external surface of 
the plates covered with numerous small, perforated, and crenulated tubercles ; pori- 
ferous zones narrow, pores unigeminal, except near the base, where they are trigeminal. 
Mouth-opening inferior, central, circular, or pentagonal, armed with five jaws ; peristome 



32 ECHINOIDEA. 

notched, dividing the circumference into ten nearly equal lobes. Apical disc central, 
superior, composed of tive genital and five ocular plates; madreporiform body large, 
extending from the right antero-lateral genital plate into the centre of the disc. Vent 
situated at the upper surface, in the margin, or at the inferior surface of the test. Spines 
small, short, subulate. Species all extinct ; genera distributed in the Oolitic and 
Cretaceous rocks. 

Types. Ecldnoconus alho-galerus, Klein. Tygaster seviisulcatus, Phillips. Discoidea 
cylindrica, Lamarck. 

Family 7. Collyritidjj;. — Test thin, circular, or oval ; ambulacral areas meeting at 
two points, more or less apart, on the upper surface ; poriferous zones narrow, pores 
unio-erainal ; tubercles small, numerous, perforated, and crenulated. Mouth-opening ex- 
central, small, round, oval ; peristome feebly fissured ; jaws unknown. Vent round, 
oval, supra-marginal ; elements of the apical disc detached ; four genital holes. Species 
all extinct, and distributed in the Oolitic and Cretaceous rocks. 

Types. CoUyrites ringens, DesmouHns. Collyrites ovalis, Parkinson. 

Family 8. EcHiNONiDiE. — Test thin, oval ; poriferous zones narrow, meeting at the 
apical disc ; pores unigeminal ; tubercles of both areas nearly equal, neither perforated 
nor crenulated ; spines stout, subulate. Mouth-opening nearly central, irregularly penta- 
gonal, and edentulous. Vent oblong or pyriform, basal or marginal, closed by anal 
plates ; apical disc nearly central ; four genital pores. One group living in tropical seas ; 
another fossil in the Cretaceous rocks. 

Types. Echinoneus cyclostomics, Leske. Pyrina Desmoulinsii, D'Archiac. 

Family Q. Echinobrtssid.e. — Test thin, circular, oblong, sub-pentagonal or clypeiform, 
covered with microscopic perforate tubei'cles, surrounded by excavated areolas ; ambulacra 
narrow, enclosed by poriferous zones, more or less petaloidal ; pores set at different distances 
apart, and united by connecting sutures. Mouth-opening small, nearly central, pentagonal, 
edentulous, in general surrounded by five lobes. Vent, opening in a sulcus, in the 
upper surface of the single inter-ambulacrum, or in a marginal depression thereof; apical 
disc small, four genital plates ; madreporiforra body extending into the centre of the 
disc. Species living and extinct, the latter distributed in the Oolitic, Cretaceous, and 
Tertiary rocks, the former in the seas of New Holland, and the Antilles. 

Types. Ecliinohrissus clutiicularis, Llhwyd. Clypeus Plotii, Leske. Catopygus carinafus, 
Goldfuss. Pygaulus cylindricus, Desor. 

Family 10. Echinolampid^. — Test thin, oblong, oval, elevated, or sub-discoidal ; 
ambulacra large, petaloid ; poriferous zones wide ; pores apart, and united by 
suture ; zones extending near to the margin. Mouth small, surrounded by five lobes. 



TERMINOLOGY. 33 

Vent transversely oblong, and infra-marginal ; apical disc small, excentral, with four 
genital holes. Some species are now living in warm seas, but the greatest number are 
extinct, and distributed in the Oolitic, Cretaceous, and Tertiary rocks. 

Types. Conodypus Leskei, Goldfuss. Echinolampas orientalis, Gray. Pygurus 
Koeniyi, Gray. 

Family W. Clypeasterid^. — Test thick, elevated or depressed, circular, elliptical, or 
pentagonal; surface closely covered with small, nearly equal-sized tubercles, sunk in 
the plates, and surrounded by ring- like areolas, tubercles carrying short hair-like spines. 
Mouth large, central, and pentagonal, armed with five strong jaws, containing the 
same number of teeth. Vent posterior, marginal or infra-marginal ; interior of the 
test divided by pillar-like processes, formed of the inner layer of the plates. The dorsal 
portions of the ambulacral areas have a petaloid form, circumscribed by large poriferous 
zones ; the basal portions are narrow, rectilineal, or branched ; the five genital 
plates form a circle round the madreporiform body, and between these are wedged the 
five ocular plates. This family includes the genera Cli/peaster, Lamk., Layanum, Klein, 
Echinarachnius, Van Phels., Araclmoides, Klein, Scutella, Lamk., Bendraster, Agass., 
Lobophora, Agass., Encope, Agass., Echinodiscus, Breynius, Mellita, Klein, Buna, Agass., 
Moulinda, Agass., ScuteUina, Agass., Echhiocyamus, Van Phels., Fibularia, Lamk., 
Lenita, Desor. 

Types. Clypeader rosaceus, Lamarck. Scutella suhrotunda, Lamarck. Ecldnarach- 
nius placenta, Gmelin. 

Family 12. EcHiNOcoRiDiE. — Test thick, oval or cordate, and sometimes conoidal; 
ambulacral areas contracted ; poriferous zones narrow, pores unigeminal ; test covered with 
small perforated and crenulated tubercles. Mouth small, excentral, tranversely oblong. 
Vent nearly of the same size, oblong, marginal or supra-marginal. Apical disc elongated, 
nearly central, with four genital pores ; the cordate forms have an anterior central depres- 
sion, and one genus has a marginal fasciole. The species are all extinct, and limited to 
the Cretaceous rocks. 

Types. Echinocorys vulyaris, Breynius. Ilulaster subglobosus, Leske. Cardiaster 
granulosus, Goldfuss. 

Family 13. Spatangid^. — Test thin, oval, oblong or cordiform, exhibiting the bila- 
teral symmetry of the Echinoidea. Vent posterior and supra-marginal, closed by a com- 
phcated series of small plates. Apices of the ambulacral areas united at the summit of 
the test. The single ambulacrum has a different structure from the antero- and postero- 
lateral pairs, and is lodged in general in a depression of the test, which extends to the 
anterior border, and forms the anteal sulcus; test extremely thin, and covered with 
small tubercles, which support hair-hke spines. Besides these there are some larger 

5 



34 ECHINOIDEA. 

crenulated and perforated tubercles for supporting large spines. There are two or four 
genital pores, placed close together in some genera, but apart in others. The eye- 
plates, five in number, are situated at the apices of the ambulacra, in a pentagonal form, 
around the genital plates. On the surface of the test of some Spatan(/id(B certain delicate 
lines are observed, having a smoother appearance than the tubercular surface of the test ; 
these are the /asc?o/(?s, which are strewed with microscopic tubercles, and destined to carry 
very delicate spines. The fascicles have a different disposition in each genus, and afford a 
good character in making definitions of the same. When the fasciole surrounds the 
ambulateral petals like an undulating groove, as in Hcmiaster, Schizaster, &c., it is jjeri- 
petalous ; when it surrounds the single ambulacrum, as in Amjjhidetus, it is internal; 
when it extends along the sides, as in ScMzaMer, it is lateral ; when it surrounds the 
circumference of the test, as in Pericosmus, it is marginal ; when it is limited to the base 
of the anal opening, it is sub-anal. Sometimes, in the same genus, more fascioles than one 
exist ; thus tlie sub-anal and peri-petalous are frequently associated together. 

Types. SjMtangus purpureas, Miiller. Brissu^ lyrifer, Forbes. Brissopsis Duciei, 
Wright. 



CIDARIDJE. • 35 



Family 1 — Cidarid^. 

Test thick, turban-shaped, more or less depressed at the oral and anal apertures. 
Mouth-opening wide, central ; peristome circular or pentagonal, without notches ; 
aperture closed by a buccal membrane, covered with small spines, metamorphosed into 
imbricated scales, upon which the pores from the zones are prolonged. 

Opening for the apical disc very large ; disc composed of five large, equal-sized, 
angular, genital plates, and five ocular plates ; vent opening in the centre, directly opposite 
the mouth ; anal membrane clothed with small angular plates, unequal in size, and variable 
in number. 

Ambulacral areas extremely narrow, composed of a great number of very small plates, 
having only minute tubercles, or rows of small granules on their surface, and never 
supporting tubercles with primary spines. 

Inter-ambulacral areas very wide, composed of large plates, rarely more than from six 
to eight in a column ; the external surface of each plate carries a large perforated 
tubercle, raised on a prominent boss, and encircled by a round or oval areola, having 
an elevated margin, on which are a circle of granules, usually larger than those filling the 
miliary zone. 

Poriferous zones narrow, extending without interruption from the margin of the buccal 
membrane to the apical disc ; pores in general unigeminal, in one genus bigeminal ; pores 
contiguous, or separated by septa more or less thick. 

Jaws, five in number, forming a very powerful lantern, moveably connected with, and 
supported by, a series of calcareous processes or auricles, arising from the inner surface 
of the test ; the teeth are more simple, and the lantern less complicated than in the 
Ecldnidce. 

The spines in this family exhibit a great variety of forms, they are large, strong, cylin- 
drical, fusiform, prismatic, club-shaped, or flattened; and their surface is covered with 
fine longitudinal lines, or with prickles or granules, having in general a linear arrange- 
ment, or a more or less irregular disposition ; the form and sculpture of the spine has a 
specific value, as its dominant characters appear to be persistent.* 

The Cidaridis are the most ancient type of the Echinoidea. The remains of different 
forms of this family are found in the Palaeozoic rocks, as well as in those of the Secondary 

* The form and general character of the spine should, in every case, be examined with scrupulous 
attention, and, whenever in fossil species the spines are found attached to their test, the facts connected 
tiierewith should be noted with the greatest accuracy. The neglect of this caution has been the cause of 
much confusion, and led to some serious errors. 



36 CIDARIS 

and Tertiary epochs. In his valuable Synopsis, M. Desor describes six genera in this 
family : these are Cidaris, Klein ; Rabchcidaris, Desor ; Diplocidaris, Desor ; Porocidaris, 
Desor ; Goniocidaris, Desor ; Palceocidaris, Desor. Of this number three are extinct — 
Bijilocldaris, Porocidaris, and Palceocidaris ; two contain both extinct and living forms 
— Cidaris and Babdocidaris ; and one is only found living — Goniocidaris. 



A. — Species from the Gault. 

Cidaris Gaultina, Forbes, MS. PI. I, fig. 2, a, b, c, d, e ; fig. 3, a, b ; fig. 4 a, b, c. 

CiDAEis Gaultina, Forhes. Morris's Catalogue of Britisli Fossils, 2nd ed., p. 74, 
1854. 
— — Woodward. Memoirs of the Geological Survey, Decade v, e.xpl., 

pi. V, 1856. 

The specimen figured in PL I, fig. 2, belongs to the British Museum, and was kindly 
communicated by my friend, S. P. Woodward, Esq., F.G.S. It consists of five inter- 
ambulacral plates, and a trace of an ambulacral area, with a number of spines. Detached plates 
of this urchin resemble those of Cidaris vesiculosa, Goldf. In the large plate (fig. 2, b), 
magnified two and a half times, the depth is greater than the breadth ; the wide circular 
areola is nearer the lower border, its margin is elevated, and surrounded by a circle of thirteen 
small tubercles, each set upon a distinct base ; the boss is flat, its summit smooth, and 
the tubercle large and distinctly perforated ; the rest of the plate is covered with a fine 
clo.se-set granulation (fig. 2, a, b). 

The remaining fragment of the ambulacral area is too imperfect for description. 

The spines vary in form ; they are in general long and slender, and taper slightly 
(figs. 2 and 3). The surface is covered with longitudinal ridges, the edges are distinctly 
serrated (fig. 2, a, and fig. 3, b), and the stem represents a miniature fluted column. The 
truncated summit shows a star-like structure (fig. 2, e), produced by the serrated ridges 
meeting around the circumference of a central circle. The neck is smooth, short, and 
thick (fig. 2, d, and fig. 3, b) ; the milled ring broad and flat, and covered with very fine 
lines ; the head is short, and the acetabulum surrounded by a line (fig. 2, d). 

In one of the broken spines that accompanies the plates the upper extremity is 
expanded and cup-like (fig. 4, a, b, c), whilst in the other spines the extremities are 
contracted and truncated (fig. 2, a, c). 

Affinities and differences. — This urchin very closely resembles Cidaris vesiculosa, Goldf., 
found in the Chalk-marl of Essen and Ruhr. The resemblance is so great between the 
German and English forms, that without a comparison of specimens a correct diagnosis 



FROM THE G/VULT AND GREENSAND. 37 

cannot be given. In Cidaris vesiculosa, Goldf., the marginal circle of areolar tubercles 
is not so prominent as in Cidaris Gaulfina, Forb., but the general character of the 
ornamentation on the plates is the same in both. The spines figured by Goldfuss 
closely resemble those of C. Gaidtina ; they have the same slender, elongated form, and 
fluted structure ; most of them are spindle-shaped, and some have an expanded cup-like 
termination, like the spine fig. 4, a. 

Locality and Stratigraphical Position. — Cidaris GauUina is a very rare urchin. I 
only know the specimens contained in the Museum of the Royal School of Mines, and the 
subject of our figures, which belongs to the British Museum ; both these fossils were 
obtained from the Gault at Folkstone. Cidaris vesiculosa, Goldf., on the contrary, has 
been collected from the Chalk-marl of Germany, and the Grey Chalk at Dover. 



B. — Species from the Upper Greensand. 

Cidaris velifera, Bronn. PI. II, fig. 2 a, b, c, d, e,f; fig. '6 a, b ; fig. 4 a, b. 

Cidaris VELirERA, Bronn. Jahrb., p. 154, the name only, 1835. 

— pisiFERA, Agassiz. Catalogus Systematicus, p. 10, 1840. 

— VELiFER, Bronn. Index Palceontologicus (" = iSa/e^iVe sp."), 1848. 
— ■ MicHELiNi, Sorignet. Ours. Foss. de I'Eure, p. 18, 1850. 

— GLOBICEPS, Qwenstedt. Handbuch der Petrefactenkunde, p. 577, pi- 49, 

fig. 17, 1852. 

— VELIFERA, Woodward. Mem. Geol. Surv., Decade v, pi. v, 1856. 

— Heberti, Besor. Synopsis des Echinides Fossiles, p. 12, 1858. 

— velifera, Desor. Ibid., p. 34, 1858. 

— — Cotieau. Paleont. rran9aise ; Echinides, pi. 1054, figs. 14 — 21, 

p. 241. 

Test small, circular, depressed ; ambulacral areas narrow and sinuous, with four rows 
of granules; inter-ambulacral areas wide, tubercles large and prominent, gradually 
increasing in size from the peristome to the apical disc, where they are globose and con- 
spicuous ; spines short, stems large and globular, surface covered with longitudinal rows 
of pustular elevations. 

Dimensions. — Height, three tenths of an inch ; transverse diameter, eleven twentieths 
of an inch. 

Bescriptioti. — This beautiful little Cidaris is one of the oldest representatives of the 
group possessing claviform spines, Sadioli j/latidarii, for all doubt about the identity of the 



38 CIDARIS 

test, and the spine appertaining thereto, is removed by the discovery of the interesting 
specimen fignred in PI. II, fig. 4, a. The spines of this species were first discovered in 
the Craie chloritce of Essen and Frohnhansen, and were named by Bronn veJifcr ; as the 
asperities on tlieir globnlar stem impart a pecuhar character to them, and that autlior, in 
his 'Index Palseontologicus,' referred them to a Salenia. M. Desor described a small 
Cidaris Heberti from the Craie chloritee of Cap la Heve, Avhich I believe to be the test of 
this species. The short diagnosis given in the ' Synopsis ' agrees so well with the speci- 
mens before me that I have no hesitation in conclnding it to be the same: — "Petite espece 
a scrobicules petits et serves, mais a tahercules trcs-r/ros, surtout a la face siijjerieure. 
Quafre rangees cle granules ambulacraires." 

The ambnlacral areas are slightly sinnous, and furnished with four rows of small 
granules (fig. 2, e) closely set together, the marginal rows being the most uniform in their 
arrangement. The narrow poriferous zones lie in a deep groove formed by the prominence 
of the adjoining granules ; the pairs of small holes are obliquely inclined, with thickened 
septa, each having a small tubercle (fig. 2, e) between thein. 

The inter-ambulacral areas have two rows of tubercles placed so near the poriferous 
zones that the inter-tubercular space in the middle of the area is about the same width as 
the ambulacra, whereby the ten rows of tubercles are situated nearly equidistant from each, 
thus imparting a regular appearance to this species (fig. 2, c, b). There are five tubercles 
in each row, which increase gradually in size from the peristome to the disc ; the three 
basal tubercles are small and set closely together (fig. 2, b), whilst the two upper tubercles 
are large and wide apart (fig. 2, f); the mammillary eminence is depressed, the areolae are 
narrow (fig. 2, e), and their margin surrounded by a circle of well-defined granules 
(fig. 2,/). The tubercle is large and prominent, and the narrow boss on which it rests 
is destitute of crenulations (fig. 2, e,f) ; the summits of all the tubercles are perforated, those 
on the upper part of the test are, however, best preserved. A broad band of granula- 
tions separates the two rows of tubercles ; five or six rows of granules are closely placed 
together ; and the granules in the band and those in the ambulacra are nearly of the same 
size. 

In the specimen figured at 4, a, there are seven spines attached to the test in their 
natural order. The spines (fig. 3, a) have a very short neck and a large globular stem, 
covered with rows of pointed elevations (fig. 3, b) rising from the midst of an apparently 
villous surface. The milled ring (fig. 4, b) is close to the acetabulum, it is moderately 
prominent, and crowded with fine lines. From the manner in which these globular spines 
are arranged on this small test, very little individual motion was possible among them, 
and yet the delicate surface of the spines, when examined with a lens, gives no evidence of 
abrasion, from the friction of moveable bodies laid so closely together as these spines were 
placed. 

Affinities and differences. — The test of this beautiful little Cidaris is nearly related to 



FROM THE GREY CHALK. 39 

Cidaris davigera, Koiiig, both in the form of the tubercles and the narrowness and depth 
of the areolae ; but in the structure of the spines there is a manifest difference, which will 
be more fully appreciated by comparing PI. IV, fig. 1, exhibiting a series of spines of 
C. clavigera, with PI. H, fig. 3, b, showing a magnified view of the spine of C. velifera. 

Locality and Stratigrapldcal Position. — W. Cunnington, Esq., F.G.S., of Devizes, to 
whom I am indebted for the loan of specimens of this species, obtained them from the 
Upper Greensand near Warminster ; I had seen the plates of the test and portions of the 
spines, but never before have I seen these parts " in situ.^' 

» The foreign distribution of this urchin is as follows : — The spines are found in the 
Craie chloritee of Essen, Prussia, and of Frohnhausen, Hesse-Cassel, and the test, 
described under the name Cidaris Ileberti, Des., was collected from the Craie de 
Vendorae, from the Craie chloritee du Cap la Heve and la Madeleine, near Vernon 
(Eure) in I'Etage Cenomanien, where it is very rare. 



C. — Species from the Greg Chalk. 

Cidaris Carteri, Forbes. PI. I, fig. 1, a, b, c, d, e,f. 

Cidaris Carteri, Forbes. Memoirs of the Geol. Survey, Decade v, pi. v, 1854. 

— — Morris. Morris's Catalogue of Brit. Fossils, 2tid ed., p. 74, 1856. 

— — Desor. Synopsis des Echinides Fossiles, p. 12, 1858. 

Test small, inflated, subconical; ambulacral areas narrow, winding, with two marginal 
rows of moniliform granules, and a deep median sulcus ; inter-ambulacral areas wide ; 
tubercles small, remote ; areolae at the equator narrow, complete, those on the upper plates 
small, elongate, and obsolete. 

Dimensions. — Pleight, eight lines ; transverse diameter, ten lines. 

Description . — Should subsequent discovery confirm the opinion that this is an adult 
test, it will be the smallest Cidaris in the English Chalk. It very much resembles, in 
many points of structure, Cidaris sceptrifera, Mant., from which it differs, however, in 
size and figure, and in the development of the tubercles and their areolae, especially those on 
the upper plates. The ambulacral areas are narrow and winding ; they have two rows of 
prominent moniliform granules on the extreme margins of the areas (fig. 1, c) ; and in the 
depth of one equatorial inter-ambulacral plate I have counted sixteen of these ; between 
them is a deep sulcus, on which two indistinct central rows of microscopic granules are 
sparsely distributed. 



40 CIDA.RIS 

The inter-aml:)ulacral areas are wide, and consist of large, deep plates (fig. 1, c), about 
four or five in each row, those at the equator are the largest ; the tubercle is small 
and perforated ; the boss is flat, with a smooth summit ; the areolae are narrow and 
complete, and encircled by a moniliform circle of sixteen small granules, raised on 
scale-like plates (fig. 1, <?) ; from the equator to the mouth the tubercles and their 
areolae gradually diminish in diameter, and on the upper surface the plates tbey are very 
deep, and their areolae small, elongated, and entirely obsolete ; the inter-tubercular surface 
of the plates is covered with close-set miliary granulations. 

The poriferous zones are narrow and deeply sunk, in consequence of the thickness of 
the plate-ornamentation ; the holes are small, the pairs oblique, and there are sixteen 
pairs opposite one large inter-ambulacral plate, one pair of holes being opposite one of the 
large marginal ambulacral granules. 

The apical disc is wide, occupying all tlie summit of the test (fig. 1 , a, b) ; the 
ovarial plates are large (fig. 1, c/), and of an irregular rhomboidal figure ; their surface is 
covered with small granules sparsely distributed thereon, and the oviductal holes are 
perforated at the outer third of the plates. The oculars are small and heart-shaped, and 
intercalated between the angles formed by the ovarials ; the orbits appear to have been 
marginal. 

Affinities and differences. — This species resembles Cidaris scejjfrifera, Mant., but the 
depth of the inter-ambulacral plates and the limited number in a column, together with 
the sraallness of the areolae and the obsolete character of those on the upper plates, prove 
that this urchin is quite distinct from that form. 

Locality and Stratigraphical Position. — The only specimen at present known was 
collected by James Carter, Esq., F.G.S., of Cambridge, from the Grey Chalk of that 
neighbourhood ; and it belongs to his collection. In Morris's ' Catalogue ' it was stated by 
mistake to have come from the White Chalk, and in M. Desor's ' Synopsis,' from the Ores 
vert superieure d'Angleterre. 

Hislorij. — This species was first figured in the ' Memoirs of the Geological Survey,' 
in plate v of the Fifth ' Decade of British Organic Remains.' The original specimen 
formed the subject of Mr. Bone's drawings for this work. 



FROM THE GREY CHALK. 41 



CiDARis VESICULOSA, Golclfms. Plate II, fig. 5, a, b, c, d ; Plate III, fig. 1, a, b, c, d, e. 

CiUARis VESICULOSA, Goldfuss. Petref. Germanise, t. i, p. 120, pi. xi, fig. 2, 1826. 

— — Agassiz. Prod. Me'm. Soc. Nat. de Neuchatel, torn, i, p. 188, 1836. 

— — Desmoulins. Etudes sur les Echiiiides, p. 332, No. 23, 1837. 

— — Bronn. Lethsea Geognostica, p. 607, pi. xxix, fig. 76, 1837. 

— — Geinitz. Charakter der Schichten und Petrefacten Kreide- 

gebirges, p. 89, pi. -xxii, fig. 1, a, b, c, d, 1839. 

— — Roemer. Norddeutschen Kreidegebirges, p. 28, 1840. 

— — Bujardin, in Lamarck, Anim. sans Vert., 2e ed., t. iii, p. 338, 

1840. 

— — Revss. Versteinerungen der Biilim. Kreideform., p. 57, pi. xx, 

fig. 14, 1845. 

— — Agassiz et Desor. Catal. rais. des £ch. Ann. des Sc. Nat., 

3e serie, t, vi, p. 328, 1846. 

— _ Broyxn. Index Palfcont., p. 301, 1848. 

— — Quenstedt. Handbuch der Petrefacktenkunde, p. 575, pi. xlviii, 

fig. 47, 1852. 

— SPINULOSA, Guh-anger. Essai d'un rep. pale'ont. de la Sarthe, p. 40, 1853. 

— VESICULOSA, Desor. Synopsis des Echinides Fossiles, p. 11, pi. v, figs. 24, 

25, 1855. 

— EffiMERi, Cotteau, in Davoust, Note sur les Fossiles speciaux a la Sarthe, 

p. 49, 1855. 

— VESICULOSA, Pictet. Traite de Paleont., 2nd ed., t. iv, p. 254, 1860. 

— — Cotteau et Triger. Echinides de la Sarthe, p. 133, pi. xxv, 

figs. 1—6, 1860. 

— — Cotteau. Note sur les Echinides recueillis en Espagne, par MM. 

Verneuil, Triger, et Collomb., Bull, de la Soc. Ge'ol. de France, 
2e serie, t. xvii, p. 375, 1860 

— — Cotteau in D'Orbigny's Paleontologie Fran9aise, t. ii, p. 222, pi. 

1050, and pi. 1051, figs. 1—6. 

Test circular, inflated, nearly equally depressed at both poles ; ambulacral areas flexed, 
depressed in the middle, and filled with from six to eight rows of close-set, nearly equal- 
sized granules, diminishing to two or four rows near the disc and peristome ; poriferous zones 
very narrow, and flexuous ; pores small, having a moniliform line of granules separating the 
pores ; inter-ambulacra wide, four to five plates in each column ; tubercles moderate in 
size, perforated, and uncrenulated, set very wide apart on the upper half of the test; 
areas round, superficial, much inflated at the border, and surmounted with a circle of 
prominent, mammillated granules. Near the disc the tubercles on the alternate columns 
become dwarfed, are destitute of areolae, and occupy the middle of a long granular plate ; 
miliary zone large, much depressed, and filled with small equal-sized granules ; discal and 
oral apertures about the same diameter. 

6 



42 • CIDARIS 

Dimensions. — Height, nine tenths of an inch ; transvei'se diameter one inch and a half. 

Description. — This urchin, which forms so characteristic a species in the Lower Chalk 
of the Continent, as shown in the table of synonyms, has hitlierto escaped the notice of 
English geologists. The species from our Upper Chalk, en'oneously referred to this form, 
being quite distinct from the true Cidaris vesiculosa, Goldf., from the Gray Chalk and 
Upper Greensand ; specimens from each of these formations I have figured in Pis. II and III. 

The test is of moderate size, much inflated at the sides, and nearly equally depressed 
at both poles ; the ambulacral areas are flexuous, depressed in the middle, and filled 
throughout with numerous rows of small, regular, close-set, equal-sized granules ; at the 
equator there are eight rows, which, near their terminations, diminish to two or four rows 
(PI. Ill, fig. 1, d) ; the inner rows are those which gradually disappear, whilst the outer 
rows are persistent throughout. 

The poriferous zones are very narrow, following the flexures of the ambulacra ; they 
are composed of small round pores, separated by a granule, the series forming a moniliform 
line down the middle of the zone, fig. 2. d. 

The inter-ambulacral areas are composed of very large plates, those in the upper half 
of the columns being the largest and most inflated ; there are from four to five plates in 
each series. The areas are circular and superficial, with very prominent borders sur- 
rounded by a circle of distinct regular mammillated granules (PI. Ill, fig. 1, d) ; on the 
under half of the test the tubercles are approximated (PI. Ill, fig. 1, b); whilst on the 
upper half they are set wide apart, from the increased height of the plates (PI. Ill, fig. 1, 
a and c) ; near the summit the uppermost tubercles on the alternate columns are imperfectly 
developed, and often destitute of areolse, and placed in the middle of a long granular plate 
(PI. Ill, fig. 1, a and c). The tubercles are moderate in size, and perforated ; the summits 
of the bosses are quite smooth, and without any trace of crenulations (PI. Ill, fig. 1, e). 

The miliary zone is large and much depressed, and provided with numerous flat, 
uniform granules, closely set together on the entire surface of the plates (fig. \, d). 

The peristome is circular (fig. 1 b), and the opening for the apical disc (fig. 1, a) is 
nearly the same diameter as the oval aperture. 

The spines of this species, according to M. Cotteau, are elongated, cylindrical, sub- 
fusiform, with compressed longitudinal ribs, more or less spinous, and denticulated, the 
processes being always at regular distances apart. Towards the base, the ribs diminish 
and disappear, and the stem is provided only with fine, close-set striae. The neck is short 
and striated, the milled ring prominent, the articular head smooth, and surrounded by a 
small groove. 

Length, twenty-five to thirty millimeters ; thickness, five millimeters. 

Variety, sj)inulosas, Agassiz : length, forty-seven millimeters ; thickness, six millimeters. 

Affinities and differences. — This species is distinguished from Cidaris sceptri/era, 



FROM THE GREY CHALK. 43 

Mant., of the White Chalk, by having fewer tubercles in the columns, which are wider 
apart in the upper portion of the test ; the areolas are likewise shallower, and the border 
more prominent. In Cidaris scepMfera the tubercles are largely developed (PI. VI, VII), 
with deep areolas surrounded by a circle of prominent granules, and with a narrow sinuous 
miliary zone. The spines likewise are large and fusiform, having their surface covered with 
prominent spiny granules. Cidaris vesiculosa, Goldf., differs from C. subvesiculosa, d'Orbig., 
in having the test flatter, the tubercles smaller, less numerous, and more apart. 

The specimens of this urchin, collected from the Upper Greensand of Wiltshire, were 
by the late Professor Forbes^ referred to Cidaris insiffiiis, Gras. Through the kindness of 
my friend W. Cunnington, Esq., F.G.S., I have been enabled to examine the beautiful 
series of this species in his collection, and in PI. II, fig. 5, have figured his largest and 
finest specimen. A careful study of these fossils has satisfied me that they are not the 
species described by Dr. Albin Gras,' and which he thus characterized : — " Aires ambula- 
craires ondulees, paraissant presenter deux rangees verticales de granules tres serrees et 
rapprochees les unes des autres ; probablement cinq tubercles inter-anibulacraires non 
creneles dans chaque rangee (quatre paraissent seulement dans notre exemplaire, dont la 
partie superieure n)anque). Sur les cinq tubercles, les trois inferieurs augmentent pro- 
gressivement de grandeur en allant de bas en haut ; leurs scrobicules et leurs cercles scro- 
biculaires ronds, saillants et formes de granules serres, sont tres-prononces, tangents entre 
eux et avec ceux de la rangee voisine ; ils sont au contraire presque effacee dans le petit 
tubercle qui vient ensuite, lequel diminue brusquement et repose pourtant sur une tres- 
large plaquette couverte de norabreux granules." The ambulacral areas in C. vesiculosa, 
Goldf., have, at the equator, six rows of small, equal-sized granules, closely arranged in 
parallel lines, and diminishing to four rows at the narrowest parts. This persistent 
structure affords a character by which the species is distinguished from C. insignis. 

The British Museum contains a fine specimen of C. vesiculosa, G(M.L, from the Gray Chalk 
of Dover (PL III, fig. 1). This test I have carefully compared with Mr. Cunnington's 
Upper Greensand specimens, and the examination has convinced me that they belong to 
the same species ; the test of the specimen from the Gray Chalk is that of a larger, and 
older individual; some of the plates, however, in the upper part of the columns, are 
proportionally more inflated ; but in all other respects its characters are identical with 
those of the Upper Greensand forms. 

The test is spheroidal, of medium size, and nearly equally depressed at both poles ; the 
ambulacral areas form narrow, flexuous, granular bands, which decline towards the 
central suture ; they are entirely filled with small, close-set, equal-sized granules, arranged 
in regular parallel rows, of which there are from six to eight at the equator, diminishing 
to four in the narrowest parts, near the peristome and apical disc ; the poriferous zones 

1 Morris, ' Catalogue of British Fossils,' 2ncl ed., p. 74. 

2 'Description des Oursins Fossiles du departemeiU de I'ls^re,' p. 21, 1848. 



44 CIDARIS 

ai'e very narrow, and the small pores are placed close together, each septum being sur- 
momited by a little granule; there are 23 pairs of holes opposite one of the large plates. 

The inter-ambulacral areas are formed of large deep plates, the limits of which are 
very distinctly defined by well-marked sutural lines ; there are four or five plates in each 
column, those at the lower part of the test are small and regular (fig. 1, b), and those at the 
upper part of the column are large, deep, and rather irregidar in figure, from the extreme pro- 
minence of the areolar margin (fig. 1, a, c); each plate, with the exception of the uppermost 
in each alternate column, supports a large primary tubercle ; it is surrounded by a shallow 
circular areola ; the boss is not prominent ; and the summit is smooth, without a trace of cre- 
nulation ; the tubercle is large, sessile, and perforated (fig. \, e); the margin of the areola is 
very prominent, which, in the larger plates especially, produces an inflation of their surface, 
and probably suggested the specific name vesiculosa (fig. \,a). A complete circle of mammil- 
lated granules, larger than those on other parts of the test, surrounds the margin of the areolae, 
and forms a prominent boundary thereto (fig. 1, d). The uppermost plate in each alternate 
column, in most specimens, is either destitute of a tubercle, or represented only by a rudi- 
mentary warty body, without areola, and situated in the midst of a long, narrow, 
imperfectly developed plate, on all sides surrounded by granules. 

The mouth is small and circular, and of the same diameter as the aperture for the 
apical disc, which is likewise entirely circular. 

Locality and Strafiffraphical Position. — The specimen figured in Plate III, fig. 1, be- 
longing to the British Museum, was collected from the Gray Chalk, at Dover, and the one 
figured in PL II, fig. 5, belongs to my friend W. Cunnington, Esq., F.G.S., Devizes, and was 
obtained from the Upper Greensand of Wilts. The specimen in my own collection is 
from the Gray Chalk of Dover. I believe this urchin is very rare, as I have seen very 
few specimens in the different collections of Cretaceous fossils. The Rev. T. Wiltshire, 
F.G.S., has communicated a fragment, collected from the Red Chalk of Hunstanton Cliff, 
together with three detached spines, of the same species. 1 am inclined to refer to this 
species the specimen, figured in PI. Ill, fig. 3, collected by C. B. Rose, Esq., F.G.S,, 
from the Red Chalk, and kindly communicated for this work. The test is much defaced 
by friction, but still many of the more remarkable characters of the urchin are well 
preserved. 

History. — This urchin was figiu-ed and described for the first time by Goldfuss, from 
some isolated plates and spines collected from the creta margacea of Westphalia; that 
author cites, as identical with Cidaris vesiculosa, a fragment from the White Chalk of 
England figured by Parkinson, but which belongs to another species, probably Cid. 
perornata, Eorb. This error has led to much confusion, for we find Cid. vesiculosa, Goldf., 
cited in many English lists as having been obtained from the White Chalk of Kent, Sussex, 
and Wilts ; whereas the new form now figured and identified with Goldfuss's species has 



FROM THE GREY CHALK. 45 

been collected only from the Gray Chalk of Dover and the Upper Greensand of Wilts. 
Cidaris vesiculosa, Forbes, is a very different form from the true C. vesiculosa, Goldf. ; and 1 
must refer the reader to the article on that species for more ample details. This species 
has been beautifully figured and well described by M. Cotteau, both in his Monograph on 
the Echinidee of Sarthe, and his continuation of D'Orbigny's Echinides de Terrains 
Cretaces, in the Paleontologie Fran9aise, a vi^ork which has profited so much by M. Cot- 
teau's extensive knowledge of this subject. This species has now been identified and 
figm'ed as British for the first time. 



CiDARis BowERBANKii, Forbcs. PI. II, fig. 1, a — d. 

Cidaris Bowerbankii, Forbes, in Dixon's Geol. and Fossils of Sussex, pi. xxix, fig. 4, 

p. 330, 1850. 
— — Forbes, in Morris's Cat. of Brit. Foss., 2nd ed. p. 74. 

Test spheroidal, depressed, ambulacra! areas with four or six rows of nearly equal- 
sized granules ; inter-ambulacral areas wide, five or six large spinigerous tubercles, with 
small areolae in each column ; miliary zone wide, filled with small, close-set, 
equal-sized granules. Spines very large, thick, and inversely conical, stems short, the 
surface covered with irregular, longitudinal rows of granulated spines. 

Dimensions. — Transverse diameter one inch ; height unknown. 

Description. — The body of this Cidaris, which is very nearly allied to C. clavigera, is 
more compressed above and below than in that species. 

The ambulacral areas are occupied by four or six small, nearly equal, granular 
tubercles in each transverse row, and the poriferous zones are narrow and slightly 
sinuous. 

The inter-ambulacral areas are wide ; the spinigerous tubercles, five or six in each 
column, have small areolae, without prominent margins ; the miliary zone is flat, and 
undepressed ; and the entire surface is thickly covered with minute nearly equal-sized 
granules, of which a circle of larger ones surround the border of the areolae. 

The primary spines, seen in situ on the test (fig. 1, a), are thick, almond- 
shaped, inversely conical bodies, with a shoi-t neck, into which the body suddenly 
contracts (fig. \, b) ; the milled ring is broad and prominent (fig. 1, c), and the acetabulum 
has a narrow rim close to the ring ; the surface is minutely granulated with small spinous 
points, arranged in regular longitudinal rows (fig. \,b); the spines which clothe the 
granular tubercles are small, compressed, conical bodies, with a striated surface (fig. \,d); 
several of these are found in situ on the plates of the test. 



46 CIDARIS 

Affinities and differences, — This species most nearly resembles C. davigcra, Kouig ; it 
is distinguished fiom that species, according to Professor Forbes, by having " the ambulacral 
segments slightly broader in proportion to the inter-ambulacrals, and instead of their 
breadth being occupied by transverse series of about four granular tubercles, two of which 
are very small and inconspicuous, there are four, or, centrally, even six, nearly equal 
granular tubercles in each transverse row. The large spinigerous tubercles of the ambu- 
lacral plates are placed in areolae, much smaller in proportion to the entire body than in 
C. clavigera, and the tubercles themselves are also smaller. The spaces between the 
rows of spinigerous tubercles are wider ; they are thickly studded with nearly equal 
granules." 

The spines of C. Bowerhankii resemble those of C. clavigera ; but the club-shaped 
head occupies the entire stem in the former, whereas in C. clavigera the club-shaped head 
is carried on the long stem. Compare PI. II, fig. 1, with PL IV, fig. 1 — 3. 

Localitg and Stratigraphical Position. — This species has been found only in the Gray 
Chalk of Dover. The fine specimen I have figured is unique, and belongs to the 
cabinet of our kind friend Dr. Sowerbank, F.R.S. 

Eistory. — First figured by Prof. Forbes, in Dixon's ' Geology and Fossils of Sussex,' 
■who likewise established the species in that work. The same specimen has been kindly 
lent by Dr. Bowerbauk to figure in this Monograph. 

CiDARis DissijiiLis, Forbes. PI. Ill, III a, figs. 1 and 2. 

CiUAEis scEPTRiFERA, Forbes, in Dixon's Geology of Sussex, pi. xxv, fig. 3. 

— DissiMiLis, Forbes, iu Morris's Cat. of Brit. Fossils, 2ud ed., p. 74. 

— — Woodward. Mem. Geol. Survey, Decade v, e.vpl. pi. v. 

Test small, depressed, ambulacral areas narrow, flexuous, with six rows of small 
granules ; inter-ambulacral plates, four to five in a column ; areolae circular, wide apart, 
surrounded by distinct secondary tubercles ; principal tubercles prominent, bosses slightly 
crenulated, the inferior oral tubercles minute, the uppermost discal, rudimentary, and 
without areolae ; miliary granules large and prominent ; spines slightly fusiform, surface 
covered with longitudinal lines of prickles. 

Dimensions. — A. Transverse diameter eleven lines ; height six and a half lines. 
B. Transverse diameter, one and one fifth inches. 

Description. — This urchin resembles Cidaris sceptrifera in its general characters, but 
was separated from that species by Professor Forbes in his MS. notes on this Cidaris. 



FROM THE GREY CHALK. 47 

The test is small and depressed at both poles ; the arabulacral areas are narrow, with six 
rows of granules at the equator, diminishing to two rows at the discal and oral apertures 
(PI. Ill a, fig. 2, c). 

The inter-ambulacral areas are wide, and the plates large, from four to five in a column . 
the areolae are circular and wide apart, the margins prominent, and surrounded by 
distinct secondary tubercles ; the boss is prominent and slightly granulated ; the tubercle 
is moderate in size and perforated ; the tubercles near the peristome are small (fig. 2, b), 
and those nearest the apical disc rudimentary (fig. 2, a), and destitute of true areolae 
(fig. 2, c). 

The miliary zone is wide and zig-zag, aud covered with large prominent granules 
(fig. 2 c), among which smaller granules are irregularly strewed. 

I have given in fig. 1 a a drawing of the fine specimen of this species from the late 
Mr. Taylor's collection, now in the British Museum, and in fig. 2, a, b, a larger specimen 
from the cabinet of the Rev. T. Wiltshire, F.G.S. 

The spines, according to Mr. S. P. Woodward, are of two kinds, " the largest above 
twenty-four lines in length, slightly swelling above the collar (two and a half lines in 
diameter), and then tapering to a fine point ; collar short, striated finely ; shaft granulated 
in hues ; spines of the lower surface very slender, three- to six-sided, serrated at the 
angles ; spines of the areolar circles two lines in length, compressed and striated." 

Fig. 1, 5, is a spine of C. dissimilis belonging to the British Museum. 

Fig. 2, d, e,f, are spines from the collection of the Rev. T. Wiltshire. 

Affinities and Differences. — This urchin so closely resembles C. sceptrifera that it was 
identified as such by Professor Forbes in Dixon's Geology of Sussex ; in his manuscript 
notes on more perfect examples he had separated it under the name C. dissimilis. All 
the best specimens known to me I have figured in PI. Ill a. 

Locality and Stratigrapliical Position. — This species was collected by Messrs. Clarke, 
Dixon, Taylor, and the Rev. T. Wiltshire, from the Gray Chalk at Dover ; the finest of 
these specimens I have now figured for the first time. Fig. \, a, b, belonged to the 
late Mr. Taylor's collection, and is now in the British Museum. Fig. 2, a, b,f, and figs. 
3 to 5, belong to the Rev. T. Wiltshire's cabinet. 

History. — This Cidaris was referred to C. sceptrifera by Professor Forbes in his 
description of that species in Dixon's Geology of Sussex. The subsequent discovery of 
more perfect specimens induced him to separate it from that fomi under the name of 
C. dissimilis in the MS. notes he left on the Cretaceous urchins. 



CIDARIS 



CLAVIGERA, 



. — PiiOFiNQUA (pars) 

CLAVIGERA, 



D. — Species from the White Chalk. 

Cll>AKIS CI-AVIGEKA, Kd)U(/. PI. IV, PI. V, figS. 1 15. 

Be Luc. Jlem. siir un Echinide singnlicr Mem. Acad. 

Roy. des Sciences, t. ix, p. 467, pi. xii, 1763. 
Andrea, J. G. R. Briefe aus der Schweiz nach Han- 
nover Geschr. in dem Jahr., 1763. 
CiDAKis PAPILLATA, vor. Leslie. Klein, Nat. disp. Eclunoderm, p. 134, pi. xlvi, 

figs. 2 and 3. 

— spiNis C1.AVICULAT1S, Parhinson. Organic Remains, t. iii, pi. iv, figs. 1 and 

21, 1811. 
Konig, in Mantell's Geo), of Sussex, p. 194, pi. xvii, 

figs. 11 and 14, 1822. 
Konig. Icoues Fossilium Sectiles, 1825. 
Agassi:. Prod. Mem. Soc. des Sc. Nat. de Neuchatel, 

t. i, p. 188, 1836. 
Besmoulins. Etudes sur les Echinides, p. 383, No. 34, 

1837. 
Besmoulins. Ibid., p. 332, No. 22, 1837. 
Geinite. Charakter der Schict. und Petref. Kreide- 

gebirges, p. 90, 1839. 

— — Agassiz. Catal. Syst. Foss., p. 10, 1840. 

— — Hisinger. Lethsea Suecica, pi. xxvi, figs. 5, 6, 1840. 

— — Roeiner. Norddeutschen Kreidegebirges, p. 28, pi. vi, 

fig. 7, 1840. 

— — • Morris. Cat. of Brit. Fossils., p. 49, 1843. 

— — Agassi: et Besor. Cat. rais. des £ch. Ann. Sc. Nat., 

3e serie, t. vi, fig. 327, 1846. 

— — Rettss. Versteinerungen der Bohmischen Kreideform., 

p. 57, pi. XX, figs. 17—20, 1846. 

— — Graves. Essai sur la top. Ge'og. du dep. de I'Oise, 

p. 692, 1847. 

— — Bronn. Index Paleeontologicus, p. 298, 1848. 

— — B^Orhigny. Prodrome de Paleont., t. ii, p. 273, Et. 22, 

No. 1246, 1850. 

— — Sorignet. Ours, de I'Eure, p. 1, 1850. 

— — Forbes, in Dixon, Geol. of Sussex, p. 338, pi. xxv, figs. 

10, 11, 14, 18, 19, 20, 1852. 

— Quenstedt. Handbuch der Petrefackt., p. 575, pi. xlviii, 

fig. 46, 1852. 
— Forbes, in Morris's Cat. of Brit. Fossils, 2nd ed., p. 74, 

1855. 
— Besor. Synopsis des Echinides Fossiles, p. 12, pi. vi, 

fig. 15, 1855. 

— Hf.berti, Besor. Ibid., p. 12, 1855. 



FROM THE WHITE CHALK. 49; 

CiDARis CLAVIGEEA, Fictet. Traite de Paleoiitol., 2nJ ed., t. iv, p. 254, 

pi. xcviii, fig. 8, 1857. 

— — Cotfeau. Palcontologie FMD^aise ; Ter. Cretac^, t. vii, 

pi. I06y, 1070, 1071, p. 285, 1862. 

— — Dujardin et Hup^. Hist. Nat. des Zooph. ; Echino- 

dermee, p. 480, 1862. 

— Heberti, Bujardin et Ilupe. Ibid. 

Tfest circular, moderately inflated, of medium size, and nearly equally depressed at 
both poles. Ambulacral areas narrow, slightly flexed, with four rows of mammillated 
granules, the inner being smaller than the outer rows ; inter-ambulacral areas wide, 
five very large tubercles in each row ; nreote deep, circular, and complete ; margin 
surrounded by a circle of mammillated granules; tubercles large and imperforate, boss 
.smooth ; miliary zone wide, not depressed, fiirnislied with large granules ; peristome 
small, subpentagonal ; apical disc large, subcircular ; spines large, clavate, crowded with 
longitudinal, prickly ribs. 

Dimensions. — Transverse diameter, one inch and three tenths ; height, seven tenths 
of an inch. 

Description. — The finest examples of this urcliin extant arc those now figured in 
Plates IV and V, the one belonging to my friend. Dr. J. S. Cowerbank, PI. IV, the 
other to the British Museum, PI. V, fig. 1 ; both these specimens were collected and 
developed by the late Mr. Taylor, and formed part of his collection of CretaceoUs Echino- 
dermata. Having had abundant materials at my disposal for the illustration of this species, 
I have endeavoured to give accurate figures of all parts of the test, as well as of the 
remarkable spines which armed it. An examination of the series I have figured will 
show how very much the spines, from difiierent parts of the test, differ from each, and how 
cautious we ought to be in founding species of Cidaris on the spines alone. 

The test is of medium size, circular, moderately inflated, and nearly eqxially depressed 
at both poles. The ambulacral areas are narrow, sliglitly flexed, and provided with four 
rows of granules ; the external are the largest, and most regular, and are elevated on 
mammillated summits close to the border of the poriferous zones; the internal rows are 
composed of smaller granules, irregular in size, arrangement, and extent ; towards the 
ends of the areas they diminish in size, and gradually disappear whilst the external 
rows are persistent throughout. A number of microscopic granules are irregularly 
scattered among the internal rows, and form a regular series at the angle of the external 
granules, on the border of the poriferous zones, and opposite each pair of holes. 

The poriferous zones are narrow, depressed, and slightly flexed ; the pores are large, 
round, and open, closely approximated to each other, and having small elevated granules 
on the septa (PI. IV, fig. I, b). 

7 



50 CIDARIS 

The inter-ambiilacral areas are wide (PI. IV, fig. 1 ; PI. V, fig. 2, a, b), Avith five very 
large, prominent tubercles in each row; the areolas are narrow, deep, and circular, closely 
approximated near the peristome (PI. V, fig. 2, b), and wide apart at the upper surface 
(PI. V, fig. 2, a) ; the margin is surrounded by a circle of small mammillated granules 
(PI. IV", fig. 1 , b, c), a little larger than those which fill the miliary zone ; the boss is 
small, and not prominent, and its summit quite smooth (PI. IV, fig. b, c) ; the tubercle 
is very large and prominent (PI. V, fig. 2 ; and PI. IV, fig. \,b, c);\i forms three fourths 
of a sphere, and the surface is imperforate ; the tubercle nearest the disc is sometimes 
surrounded by a rudimentary areola (PI. IV, fig. 1, a ; PI. V, fig. 2, a), and placed 
wide apart from its penultimate fellow. The areolas at the under surface are so closely 
approximated that many of them are separated only by a single row of granules. 

The apical disc (PI. V, fig. 3) is wider in diameter than the peristome ; the five ocular 
plates are large, with prominent orbits surrounded by a radiated structure; the ovarial 
plates have a rhomboidal figure, with the hole distant from the border ; the anal plates 
are well preserved in the specimen fig. 3, in which sixteen plates remain i7i situ; the 
surface of all the elements of the disc is covered with small granules, set well apart from 
each other; fig. 3 shows the disc and its elements magnified two and a half times. 

The jaws and teeth are in situ in the specimen belonging to the British Museum 
(PI. V, fig. 1) ; the peristome is small (fig. 2, b) ; and more than half the opening was 
filled by a buccal membrane, on which two or three rows of scale-like plates are disposed 
in an imbricated manner. PI. V, fig. 4, exhibits the buccal membrane and its plates 
magnified two and a half times. 

The form of the spines varies in different parts of the test. In general they are 
claviform, more or less developed, with massive bodies, elongated necks, and small 
articular heads. The body and neck are ornamented with numerous longitudinal ridges ; 
those on the massive body develope a denticulated, spiny margin, as seen in PL IV, fig. 5, 
and in other series of spines figured in this jjlate. The denticulated ridges are sometimes 
prominent and regular, unequal, oblique, and rudimentary ; on the neck the ridges are in 
general smaller, longitudinal, and with finer denticulations on the margin ; at the inferior 
third of the neck they diminish in size and disappear, and are replaced by granules, which 
likewise fill up all the intermediate space between the ridges, both on the neck and 
massive head. In some spines, with a large head and short neck, the weight of the 
spine is diminished by a series of canals, which extend into the head beneath the spaces 
between the ridges; the head is sometimes traversed by a large channel, opening at the 
sumn)it, as in a specimen (PI. V, fig. G) from the Eev. T. Wiltshire's collection. The 
collar is very small, and finely striated ; the milled ring is narrow, and separated from the 
collar by a depression ; both ring and depression being finely milled ; the acetabulum (fig. 
2) is moderately deep, with a well-defined ring round the margin. In Plate IV, I have 
figured the finest specimen extant of this species ; it belongs to my friend Dr. Bowerbank, 
and shews two tests with their spines attached in situ. This specimen exhibits the various 



FROM THE WHITE CHALK. 51 

forms of the spines in different regions of the shell, and the series of figures between 
3 and 23 shows some of the extreme shapes these appendages assume. 

Affinities and Differences. — This urchin is readily distinguished from other species of the 
White Chalk by its small test, equally depressed at both poles, narrow areolae, prominent 
imperforate tubercles, and large claviform spines, more or less elongated, and covered with 
spinous ridges. In this respect it resembles C. Bowerbankii, Forb., PI. II, fig. 1, from 
which it is distinguished chiefly by the character of the spines, and the larger size of the 
inter-ambulacral tubercles. Compare PI. II, fig. 1, a, with PI. IV, fig. 1. 

LocaJity a7id Sfrafiyrapliical Position. — This is the most common Cidaris in our 
White Chalk ; it is found at Woolwich, Gravesend, Lewes, Brighton, and in the same 
formation in Wilts and Dorset. The specimens figured in Pis. IV and V were found 
near Woolwich, and developed by the late Mr. Taylor. The grand s[)ecimen figured in 
PI. IV is in the possession of Dr. Bowerbank, that in PI. V, showing the dental apparatus, 
peristomal plates, and apical disc, belongs to the British Museum. 

It is very abundant in the Etage Senonien of France, and found, according to M. 
Cotteau, at Dieppe, Fecamp, Tancarville (Seine-Inferieure) ; Falaise (Somme) ; Vernonnet, 
Giverny, Clachaloze, Petit-Andelys, Pinterville pres Louviers, Hougue-marre, Sinneville 
(Eure) ; Notre-Dame-du-Thil, Mory la Herelle, le Mesnil-Saint-Fermin, Pouilly La- 
boissiere (Oise) ; Maintenon, Chateau- GaiUard (Seine-et-Oise) ; le Mesnil-Saint-Thomas 
(la Poterie) (Eure-et-Loire). 

History. — This urchin was first figured and described by De Luc in 1763, and after- 
veards by Leskeand Parkinson ; in 1823 by Mr. Koenig, in Mantell's ' Geology of Sussex,' 
who named it C. davigera. The first accurate description of the test and spines was made 
by M. I'Abbe Sorignet, who pointed out the size and imperforation of its tubercles as 
important diagnostic characters. It has recently been well figured by M. Humbert for 
M. Cotteau in the ' Paleontologie Fran9aise ;' and Mr. Bone has given most ample details 
from all the best English specimens that I am acquainted with. 

Cidaris serrifkra, Forbes, 1850. PI. XI, fig. 1, a, b, c, d, e,/, r/, h, fig. 6. 

CiDAius CLAVIGERA, Revss. Versteinerungeii der Bohmischen Kreidef., p. 57, pi. 
x.\, fig. 21, 1845. 

— SEiiRirERA, Forbes, in Dixon's Geo), and Foss. of Sussex, p. 338, pi. xxiv, 

figs, 15 — 19, and pi. xxv, fig. 2, 1850. 

— PUNCTILLUM, Sorignet. Oursins Foss. de I'Etire, p. 9, 1850. 

— SEKEIFERA, Forbes, in Morris's Cat. of Brit. Foss., 2nd ed., p. 75, 1854. 

— PUNCTILLUM, Desor. Synopsis des Echinides Foss., p. 15, 1856. 

— — lhijari/i?i et Hup^, Zoophytes ; fichinodermes, p. 481, 1862. 

— SEKRTFERA, Cotteau. Paleontologie Fran9ai8e ; Ter. Cret. ; Ecbinides, torn. 

ii, p. 293, pi. 1071, figs. 5—15, 1863. 



52 CIDARIS 

Test small, circular, convex above, flat below, poriferous zones narrow, depressed, 
slightly flexed, pores oval, approximated, separated by a small granule ; ambulacral areas 
sinuous and depressed in the middle, with from six to eight rows of small, round granules ; 
inter-ambulacral areas wide and inflated above, with four to five small perforated tubercles 
in each row, placed wide apart, with a miliary zone between them ; spines long, slender, 
cvlindrical, covered with longitudinal, compressed, spiny ribs, having a wide valley and 
uranulated surface between them. 

Dimensions. — Transverse diameter, one inch and one sixth; height, six tenths of 
an inch. 

Description. — '^I'his beautiful urchin was distinguished by Professor Forbes from 
C. clavigera, for which it had been mistaken by Reuss, and was first figured in Dixon's 
' Geology of Sussex;' it forms a well-marked species, which is very rare in our Cretaceous 
rocks. The test is small, and circular ; inflated at the equator and upper surface, and 
flattened below; the poriferous zones are slightly flexed, narrow, and depressed; the pores 
are small, oval, and approximated ; there is a granule between them on the septum ; and 
an oblong transverse ridge between each pair. The ambulacral areas are narrow, and 
slightly undulated ; the plates incline gently towards the median suture, and are provided 
with from four to six rows of small, close-set granules, of which the external rows are the 
largest, and raised on mammillated eminences ; the smaller and shorter middle rows 
disappear near the disc and the peristome, where there are only the two external rows 
of mammillated granules ; there are from fifteen to seventeen files of granules opposite 
one of the large plates. The wide inter-ambulacral areas are slightly inflated above and 
near the equator, and have from four to five deep plates in each series ; the areolae are 
small, and gradually increase in diameter from the peristome to the uppermost tubercle ; 
on the uppermost plate of each alternate series the tubercle is nearly obsolete ; the border 
of the areola is a little elevated, and surrounded by a circle of small, spaced-out, mammil- 
lated granules (fig. 1, d), a little larger than those which fill the miliary zone; the boss 
is small, the summit smooth, and the tubercle perforated in all the specimens I have 
seen ; the inter-tubercular spaces and central miliary zone are filled with a fine, uniform, 
close-set granulation ; on the upper part of the shell the tubercles nearest the disc are 
small, imperfectly developed, and surrounded by the merest trace of an areola; the 
sutures of the plates are depressed and conspicuous; the peristome (fig. \,h)vi small, 
circular or subpentagonal ; the discal opening is larger than the peristome, and sub- 
pentagonal ; a portion of the disc, concealed in the specimen (fig. 1, a), exhibits a finely 
granulated surface. 

In a fossil I collected twenty years ago at Lewes, in Sussex, many of the spines 
are preserved in situ on the fragment of the test (fig. 1, e,f,g)\ they aie long, slender, 
and cylindrical, having seven or eight compressed ridges, with a denticulated border; the 



FROM THE WHITE CHALK . 53 

valleys between the ridges are concave, and the surface of these is very finely granulated ; 
the neck is long and smooth (fig. 1,/, and fig. 2); it is bounded by a fine line, and 
beyond this is a narrow circle with microscopic lines conducting to a milled ring, which is 
prominent and finely sculptured (fig. \,f, and fig. 2); the head is small, and the rim of 
the acetabulum striated; the small secondary spines are flat and conical (fig. 1, li), and 
have the surface ornamented with fine longitudinal lines. 

Affinities and Differences. — This species is allied to Cidaris vesiculosa, Goldfuss, but 
distinguished from that form by having the test more regularly convex, the plates of 
the inter-ambulacra less inflated, and fewer tubercles in each series. The spines of the 
two species are likewise different. It resembles Cidaris sceptrifera, Mantell, but has smaller 
areolas, less prominent scrobicular circles, fewer tubercles in each column of plates ; and the 
spines are very distinct (compare for example PI. VII, fig. 1, with PI. XI, fig. 1 ). According 
to Professor Forbes, it differs from Cidaris snhvesicuhsa, d'Orbigny, in having the inter- 
ambulacra composed of large plates with impressed areolae around the spiniferous 
tubercles, four to six in the perpendicular row. Tubercles larger in proportion to the 
areolae than in the last species. Superior plates with indistinct tubercles, but not so 
obsolete as in C. subvesicidosa. Granulated portion of the plates finely grained ; the 
sutures are not impressed ; the avenues of pores, of which about fourteen correspond to 
the largest plate, are broader in proportion to the ambulacra. There is a tubercle 
between each pore, and an oblong transverse ridge between each pair. 

Locality and Stratigraphical Position. — I collected, about twenty years ago, a 
specimen of this urchin with the spines attached to the test, in the Upper Chalk, at Lewes, 
in Sussex ; the example of this species figured in Dixon's work was obtained from the 
same locality. The fine fossil which I have figured in PI. XI, fig. 1, was kindly com- 
municated for this Monograph by Henry Willett,Esq.,F.G.S., Brighton. This specimen 
appears to be the original fossil which was figured before by Sowerby in Dixon's ' Geology 
of Sussex ;' if so, it formed the subject of Professor Forbes' observations. 

In France this urchin is very rare ; it was found in the Etage Senonien at Civieres, 
Giverny (Eure) ; Royan (Charente-Inferieure). 

History. — This species was first well figured as Cidaris serrifera by Professor Forbes 
in Dixon's ' Geology of Sussex' in 1850. The same year M. I'Abbe Sorignet described 
it under the name C. punctillum in his work on the Fossil Urchins of the Department of 
the Eure ; as this account was not accompanied by a figure, I have retained the name 
of the figured specimen. In 184. "3, Prof. Reuss figured this Cidaris in liis fine work on 
the Fossils of the Bohemian Chalk-formation, and erroneously referred it to Cidaris 
claviyera, Konig, from which it differs in many important details both in the structure 
of the test and spines. 



54 



CIDARIS 



CiDARis scEPTRiFERA, Muntell. PI. V, figs. 16, 17; PI. VI; PI. VII, figs. 1, 2; PI. 

VII a, figs. 1, 3. 



CiDAKIS CUCUMERINA, 
— SCEPTRIFERA, 



— CRETOSA, 

— VESICULOSA, 

— SCEPTRIFERA, 



Parkinson. Organic Remains, vol. iii, pi. iv, fig. 2, 1811. 
Mantell. Geol. of Sussex, p. 194, pi. xvii, fig. 12 (spine), 

1822. 
Agassiz. Catal. Syst. Ectyp. Foss., p. 10, 1840. 
Ranter. Norddfiitscheu Kreidegebirge, p. 28, 1840. 
Morris. Catalogue of Brit. Foss., p. 49, 1843. 
Agassis et Desor. Catal. rais. des Echinides ; Ann. Sc. 

Nat., 3e ser., t. vi, p. 328, 1846. 
Renss, pars. Versteinerungen der Bohmisclien Kreidefor- 

nialion, p. 57, pi. x.t, fig. 15, 1846. 
Graves. Essai sur la Topogr. Geo), dii Dep. de I'Oise, 

p. 688, 1847. 

— — Bronn. Index Palaeontologicus, p. 298, 1848. 

— — d'Orbigny. Prod, de Pal. Strat., t. ii, p. 2/4, 1850 

— — Sorignet. Ours, de I'Eure, p. 6, 1850. 

— — Forbes, in Dixon, Geol. of Sussex, p. 338, pi. xxv, figs. 3 — 7, 

1850. 

— — Forbes, in Morris, Catal. of Brit. Foss., 2nd edit., p. 74, 1854. 

— — Desor. Synopsis des Echinides Foss., p. 13, pi. v, fig. 28, 

1855. 

— — Woodward. Mem. of the Geol. Survey, Dec. v, expl. to 

pi. V, fig. 12, 1856. 

— — Leymerie et Raulin. Stat. Geol. dii Depart, de TYoune, 

pp. 510—620, 1858. 

— — Coquand. Synops. des Foss. Form. Cret. du Sud-Ouest de 

la France; Bull. See. Geol., 2e ser., t. xvi, p. 1013, 
1860. 

— — Cotteau et Triger. Ech. du Dep. de la Sarthe, p. 253, 

pi. xlii, figs. 1—8, 1860. 

— — Cotteau. Paleont. Fran9aise, p. 251, pi. 1056-57-58, 

1863. 

— — HupL Hist. Nat. Zooph. ; Eehinoderraes, p. 480, 1862. 

Test moderately large and inflated ; more or less elevated, and nearly equally flattened 
at both poles ; ambulacral areas narrow, depressed, flexuous, with six rows of grannies in 
the middle, diminishing to four rows above and below ; poriferous zones narrow, winding, 
and depressed ; inter-ambnlacral areas wide ; plates very large, five to six in a column ; 
areolae deep, circular, with an elevated, prominent, scrobicular margin, encircled by a 
series of small granules, scarcely larger than those of the miliary zone ; boss not prominent, 
summit feebly crenulated in young, and smooth in old shells; tubercle moderate in size 
and perforated ; proximal discal plate in each column with a rudimentary tubercle, and an 
elongated obsolete areola; miliary zone filled with small, equal-sized granules, much 



FROM THE WHITE CHALK. 55 

depressed along the line of all the sutures ; apical disc wide ; ovarial plates thick, large ; 
ocular plates heart-shaped ; spines long, cylindrical, fusiform, enlarged at the inferior third, 
and tapering gently to the summit ; surface covered with regular, longitudinal rows of 
spiny, projecting granules, the intervening space being finely shagreened. 

Dimensions. — Height, one inch and four tenths ; transverse diameter, one inch and 
three tenths. 

Description. — A very good figure of a fragment of the test and spines of this urchin 
was given in Parkinson's ' Organic Ren)ains,'^ pi. iv, fig. 2, and a fair drawing of the 
upper surface of the shell in pi. i, fig. 11 ; both were, unfortunately, unaccompanied by 
any description. 

This beautiful species attains a considerable size ; the test is circular, and nearly 
equally depressed at both poles (PI. VI, fig 1, c) ; the ambulacral areas are very narrow 
and flexuous, with six rows of granules at the equator, diminishing to four rows at both 
poles ; the external rows are the largest and most persistent, and the internal rows are 
found only in the wide portion of the area ; in large shells there are many smaller granules, 
dispersed among the regular rows (PI. VT, fig. 1, d) ; the poriferous zones are very narrow 
and depressed, following the flexures of the areas ; the pores are small, round, closely 
approximated, and disposed obliquely, having a minute granule on the septum, and there 
are twenty-four to twenty-six pores opposite one of the larger plates (fig. 1, r/). 

The inter-ambulacral areas are very wide, and there are from four to five large plates in a 
column ; in consequence of the prominence of the scrobicular circle, each plate is thickened 
at the middle, and the lines of sutures between the plates are all very much defined, in 
consequence of the plate sloping away from the scrobicular circle to the suture ; the areolas 
are wide and circular, and surrounded by a thick, prominent border (fig. 1, d), encircled by a 
series of seventeen granules, each raised on a distinct, shield-like, mammillated plate ; the 
boss is not prominent, its summit is feebly crenulated in young shells, and smooth in old 
ones (PI. VI, fig. 1) ; the tubercle is moderately large and perforated ; the plates near the 
peristome (PL VI, fig. 1, b) are disproportionately small compared with those of the 
equator (fig. 1, c, d) ; and the last plate of each column in old shells (fig. 1, a, e,f) has 
an elongated form, with a rudimentary tubercle, and curious elongated furrow, representing 
an obsolete areola. Mr. Bone has given most accurate drawings of this remarkable plate 
from the fiue specimen in the British Museum ; the singular star-like structure which 
these plates form on the upper surface of the test, surrounding the large apical disc, forms 
a remarkable character of this species, fig. 1, a. 

The miliary zone is narrow, zig-zag, depressed in the middle, and provided with fine,close- 
set, nearly equal-sized granules, very much smaller than those surrounding the areolas. 

1 ' Organic Kemaius,' vol. iii, pi. iv, fig. 2, 



56 CIDARIS 

The apical disc is very wide (PI. VI, fig. 1, a) ; the ovarial plates are large, thick, 
irregular pentagons (fig. 1, y), and the ocular plates are heart-shaped; the surface of 
both series is covered with a close-set granulation ; the ovarial and ocular holes are very 
conspicuous in this species ; within the ovarials the external circle of anal plates are found 
i// siiu (fig. 1, a,ff, //). 

The mouth-opening (PI. VI, fig. 1, b) is nearly circular, and smaller than the anal 
opening; the jaws are strong and powerful, as seen in PI. VII, fig. 1, a, b. 

The spines are long, cylindrical, and fusiform, thickest at the lower third, and tapering 
gently from thence to the point (PI. VI, figs. 2 — 5) ; they are covered with small, spiny, 
equal-sized granules, the points of which are directed outwards ; they are arranged in 
regular, longitudinal rows, with a valley between them ; the prickles diminish in size near 
the collar, and at the summit of many of the large spines the rows of granules form a 
stellate termination (PI. VI, fig. 3, a, b, c) ; the valleys are covered with a finely corriigated 
surface, the eminences forming microscopic longitudinal lines. The neck is very short 
and delicately striated (fig. 4, b), the head moderately large, and the milled ring not 
prominent ; the rim of the acetabulum is feebly crenulated, and its concavity contains 
a deep depression for the round articular ligament ; the length of the large spines, figured 
in PI. VI, figs. 3 and 4, contained in the British Museum, is two inches and nine tenths. 
One figured by ^I. Cotteau, from the French Chalk, is three inches long. 

Affinities and Differences. — Cidaris sceptrifera so closely resembles, in many points of 
structure, Cidaris subvesiculosa, d'Orbigny, that by some they have been thought to be 
varieties of one species ; the facts on which their distinctness may be maintained are the 
following : Cidaris subvesiculosa has a more elevated test, with a greater nimiber of plates 
in a column, the areolas are smaller and less depressed, the circle of scrobicular granules 
is less prominent, and the obsolete tubercles on the upper plates of the columns are 
smaller, more numerous, and differently formed ; the grannies covering the miliary zone 
are smaller, and more regularly disposed in rows radiating from the areola. The grand 
distinction is found in the spines, which are much smaller in C. sceptrifera, tapering, but 
not fusiform, and covered with longitudinal serrated lines. Compare the different excellent 
figures of Cidaris subvesiculosa, d'Orbigny, in PL VIII, with the admirable drawings of 
Cidaris sceptrifera, Mantell, in PI. VI and VII. 

Locality and Stratigrapldcal Position. — Cidaris sceptrifera is found in the Upper 
"White Chalk of Kent, Sussex, and Wilts. The truly magnificent specimens figured in 
Pi. VI, fig. 1, and PI. Vllrtf, fig. I, belong to the British ]Museum; the specimens figured in 
PI. VI, fig. 2, and PI. VII, fig. 1, belong to the Museum of the Royal School of Mines. 
I need scarcely add they are the finest known. 

In France, M. Cotteau enumerates the following localities in which this species is 
found : Dieppe (Seine- Inferieure) ; la Faloisc (Somme) ; Vernonnet, Giverny, Civieres, 



FROM THE WHITE CHALK. 57 

Petit-Anclelys, Pinterville pres Louviers, Senneville, Evreux (Eure) ; Notre-Dame-du-Thil 
Frocourt, les Blamonts, Thcrdonne, Pouilly, Reims, Eroyes, la Herelle, le Mesnil-Saint- 
Finnin, Mory (Oise) ; Clialons-sur-^Manie (Manic) ; la Fertc-Loupiere (Yonne) ; Claclialoze, 
Maintenoii (Seine-et-Oise) ; Marion (Sarthe) ; Villedieu, Limeray (Loir-et-Cheij ; le 
Menil-Saiiit-Tliomas (la Poterie) (Eure-et-Loir) ; Anbeterre (Charente) ; Talmont, Saint- 
Georges, Royan (Charente Inferieure). Etage Senonien. Saiut-Paterne (Sarthe) ; Etage 
Tiironien, zone Terebratella Bourgeoisii. 

History. — First figured by Parkinson in 1811; the test and spines arc both well 
drawn, so that no doubt as to the species intended can exist, although no description of 
the urchin was given. In 1823, Mantell figured one of the spines, and gave it the 
name which it still retains. This species was not indicated in France until 1840, when 
it was entered in M. Agassiz' Catalogus si/sfemaficus ; since then its test and spines have 
been found in the localities enumerated above. 



CiDARls SUBVESICULOSA, (V Orhigny. PI. VIII, figs. 2, 4, 5, G. 

CiDARES PAPILLAT.E, Parliinson. Organic Remains, vol. iii, p. 39, pi. iv, fig. 3, 

1811. 
CiDARis CKETOSA, Mantell. Geol. of Sussex, Trans. Geol. Soc.,vol. iii, p. 205, 

18:55. 

— PAPiLLATA, Mantell. Geol. of Sussex, p. 194, pi. xvii, fig. 13, 1822. 

— CKETOSA, Morris. Catal. of British Fossils, p. 50, 1843. 

— VESICULOSA, Morris. Ibid,, p. 51, 1843. 

— PAPILLATA, Reiiss. Die Versteinerungen der Bohmischen Kreideforma- 

tion, p. 57, pi. XX, fig. 22, 1846. 

— CRETOSA, Graves. Essai suf la Topog. Geog. du Departement de 

rOise, p. 688, 1847- 

— — Bronn. Index Palaeontologicus, p. 298, 1848. 

— SUBVESICULOSA, cfOrhigny. Prod, de Paleontol. Strat., t. ii, p. 274, 1850. 

— OVATA, Sorignet. Ours. Foss. de I'Eure, p. 9, 1850. 

— AMBIGUA, Sorignet. Ibid., p. 10, 1850. 

— VESICULOSA, Forbes, in Dixon's Geol. of Sussex, p. 338, pi. xxv, figs. 

1—4, 1850. 

— — Quenstedt. Handbuch der Petrefactenkuude, p. 375, pi. 

xlviii, fig. 49, 1854. 

— — Forbes, in Morris's Catalogue of British Fossils, 2nd ed., 

p. 75, 1854. 

— SUBVESICULOSA, Desor. Synopsis des Echinides Foss., p. 13, pi. v, fig. 27, 

1855. 

— GRAKULO-STRIATA, Desor. Ibid., p. 14, pi. v, fig. 26, 1855. 

— OVATA, Desor. Ibid., p. 14. 

— AMBIGUA, Desor. Ibid., p. 15. 

8 



58 CIDARIS 

CiDABis SUBVESICDLOSA, Coqiiatid. Bull. Soc. Ge'ol. de France, 2e serie, tora. xvi, p. 

1013, 1860. 

— — Cotteau et Triger. £chin. du dep. de la Sarthe, p. 250, pi. 

xli, figs. 1—9, 1860. 

— — Cotteau. PaleoDtologie Fran9aise, Ter. Cretace, tome vi, p. 

257, Pis. 1059—1061, 1863. 

Test large, circular, inflated, nearly equally depressed at both poles ; ambulacral areas 
slightly flexed, wide, with six rows of nearly equal-sized granules at the equator, 
diminishing to four and two rows at the poles, the external series being the largest and 
most persistent ; poriferous zones narrow, depressed, and composed of simple oval pores, 
separated from each other by an elevation of the septum ; inter-ambulacral areas wide, si,x 
or seven large plates in a column ; the three equatorial plates with large areolae, those 
near the peristome small, and the two upper plates near the disc with small rudi- 
mentary tubercles ; areola) circular, depressed, surrounded by a ring of mammallated 
granules, boss flat, with a smooth summit, tubercle moderate and perforated ; miliary zone 
wide, filled with fine close-set homogeneous granules, disposed in very regular horizontal 
lines, radiating from the scrobicular circle to the border of the plates ; peristome small 
and pentagonal ; apical disc large, ovarial plates wide, narrow, and perforated at a 
distance from the border ; ocular plates heart-shaped, with marginal orbits. Two con- 
secutive series of cuboidal anal plates arranged within the pentagonal area formed by the 
ovarials ; vent small and sub-central. 

Spines slender, elongated, and cylindrical ; surface covered wjth longitudinal elevations, 
having a fine serrated or spinous border gradually becoming attenuated towards the base ; 
neck short, with longitudinal lines ; milled ring prominent, articular surface without 
crenulations. 

Dimensions. — Specimen fig. 5 — height, one inch and one tenth ; transverse diameter, 
one inch and seven tenths. 

Description. — This urchin has been mistaken for Cidaris vesiculosa, Goldf., from 
which it difiers, however, in many important characters ; the.se have already been indicated 
in the description of that species (p. 41). The test is in general of moderate size, and 
nearly equally depressed at both poles ; the ambulacral areas are slightly flexed, with six 
rows of granules at the equator ; the external rows have larger mammillated granules than 
the inner rows, which gradually disappear as the area becomes narrower near the peristome 
and disc ; the poriferous zones are narrow, depressed, and sub-flexuous ; the pores are 
oval, and oblique as they approach the disc, and the septa have small elevated granules 
between the holes. The inter-ambulacral areas are large, the plates wide and deep, six or 
seven in a column (PI. VIII, figs. 4, 5), the areolas are circular and moderately depressed ; 
they are widely spaced out at the upper surface, and placed closer together at the infra- 



FROM THE WHITE CHALK. 59 

marginal region and near the peristome ; the margin is surrounded by a complete circle of 
large mammillated granules raised on sliield-like plates. On the two uppermost plates of 
each column the areolae are very narrow, or altogether obsolete (fig. 4, a). The boss has a 
flat smooth summit (fig. 1, c), and the large tubercle is deeply perforated (fig. 1, c and d). 
The miliary zone is very wide at the equator, and becomes narrower near the peristome 
and the disc. It is more or less depressed in the middle, along the line of the sutures, 
and covered with fine homogeneous granules set closely together; the granules are 
arranged in regular horizontal lines (fig. 1, c, d, e), which radiate from the circumference 
of the areolae to the border of the plate. 

The apical disc is large and pentagonal (fig. 4, a, b), and well preserved in situ in the 
fine specimen, fig. 4, a. The five large ovarial plates have an irregular rhomboidal form, 
with the ductal holes near the border ; the oculars are heart-shaped, and have marginal 
orbits ; the anal plates form a double series within the discal circle, and the vent (fig. 4, b) 
is a small e.xcentral aperture with a third series of small plates on its anterior part only. 
All the elements of the disc are closely covered with the same style of grannies that fill 
the miliary zone. 

The peristome, smaller than the discal opening, is of a pentagonal form ; in none of 
our specimens are the dental pyramids preserved. 

The spines are long, slender, cylindrical, with longitudinal ribs having a spinous 
border (fig. 2, a, b) ; the valleys between the elevations have a finely chagreened surface ; 
the neck is short and striated, the head moderately large, and the milled ring prominent 
(fig. 2, c). The acetabulum has a smooth rim. One spine must have measured 2^ inches 
in length. The large mammillated granules surrounding the areolae supported small, fiat, 
triangular spines (fig. 6), having their surface ornamented with longitudinal microscopic 
lines, and articulated to the tubercle by a semicircular depression at the base. I have 
figured one of these scrobicular spines at fig. 6, where the line shows the natural size, and 
the figure is enlarged four diameters. 

Affinities and differences. — This species has long been considered to be the Cidaris 
vesiculosa, Goldf., but is distinguished from that urchin in having the ambulacra less 
flexed, a greater number of plates in the inter-ambulacral colnmns, the upper tubercles' 
of both series rudimentary, and in having the granvdes in the miliary zone arranged in 
horizontal rows. Cidaris vesiculosa, Goldf., has a smaller test, the ambulacra much more 
flexed, the plates in a column fewer, the tubercles consequently wider apart, the upper 
tubercles largely developed, and the grannies in the miliary zone not arranged in hori- 
zontal rows. The spines in C. snbvesiculosa are long, slender, and tapering ; those in C. 
vesiculosa are shorter and thicker. This urchin so closely resembles C. perlafa, Sorignet, 
and C. Vcndocinensis, Ag., that they appear to me to be only varieties of C. subvesiculosa, 
d'Orbig. ; the spines of the latter likewise closely resemble those attributed to C. serrata, 
Desor. It is possible that if a collection of good type-specimens of these different reputed 



60 CIDARIS 

species were compared with each other, they would be found to be only so many cognate 
varieties of one forui. 

Locality and Stratigraphical position. — Tliis species is found in the Upper Chalk of 
Kent, Sussex, and Wilts. 

In France M. Cotteau gives the following localities in which it is very common in the 
Etages Turonien et Senonien : Bolbec (Seine-Inferieure) ; Houguemarre, Vernonnet, Petit- 
Andelys (Eure) ; Notre-Dame-du-Thil, Tartigny (Oise) ; la Ealoise (Somme) ; Saint- 
Eraimbault, IMar^on, les Menus (Sarthe) ; Yilledieu, Villiers (Loir-et-Cher) ; Semblancay, 
Limeray (Indre-et-Loire) ; Briolay (Maine-et-Loire) ; Barbezieux, Aubeterre, Lavalette, 
Salles (Charente) ; Royan, Saint-Georges Talmont, Saintes, Cognac (Charente-Inferieure) ; 
Perigueux, Tretissac, Neuvic (Dordogne) ; Bugarach, Soulatge (Aude). 

History. — This urchin was first figiu-ed by Parkinson in 1811. The test and spines are 
sufficiently well drawn, in the absence of a description, to enable us to identify the species. 
In 1822 Mantell described, under the name C. cretosa, a Cidaris represented by Parkin- 
son ('Organic Remains,' Vol. Ill, PL I, fig. 11), and united to fig. 3, PI. IV, of the 
same work, which served as the type of C. snhvesicidosa. Professor Eorbes identified this 
species with the C. vesiculosa, Goldf., and figured it under that name in Dixon's ' Geology 
of Sussex.' In 1850 M. d'Orbigny, in his 'Prodrome de Paluontologie,' separated it from 
that form under the name subvesiculosa, which has been adopted by MM. Desor, Cotteau, 
and other authors. 



Cidaris Merceyi, Cotteau. PI. VIII, figs. 1, 2, 3. 

Cidaris Merceyi, Cotteau. Paleont. Fran9aise, Ter. Cretace Ecbinoderraes, toin. vii, 
p. 281, pi. 1068, 1862. 

Test large, circular, and elevated above, inflated and depressed below; ambulacra 
narrow, depressed, and slightly flexed ; two rows of small regular mammillated granules 
on the external border, and four rows of smaller, irregular granules on the central portion 
of the area ; poriferous zones narrow, flexed, composed of round pores in oblique pau's ; 
inter-ambulacra wide, six or seven large plates in a column ; tubercles well developed at 
the base and equator, but small and obsolete on the upper surface ; areolae circular, 
depressed, margin surmounted by a circle of regular mammillated granules. 

Dimensions. — Height, two inches ; transverse diameter, two and a half inches. 

Description. — This remarkable urchin, which appears to be an elevated variety of 
Cidaris subvesiculosa, has been described by j\I. Cotteau as a distinct species under the 



FROM THE WHITE CHALK. 61 

name C. Mcrceyi. The test is large and circular, elevated at the upper surface, inflated at 
the equator, and flat at the base (fig. 1, a, b). The arabulacral areas are narrow and 
slightly flexed, much depressed at the medium suture, and furnished at the widest part 
with six rows of granules. The two marginal rows have larger granules, very regular in 
size and arrangement, and raised on small plates (fig. 1, c) ; the four inner zones are 
much smaller and less regular (fig. 1, c) ; the poriferous zones are narrow, deeply sunk, and 
slightly bent ; the small round pores are disposed in oblique pairs, of which there are 
twenty-one, opposite one large equatorial plate (fig. 1, c). 

The inter-ambulacral areas are wide and largely developed ; there are from six to 
seven plates in each column, of which the four or five lower plates have large areolae, with 
moderately sized tubercles ; the two uppermost plates are destitute of areolae, and have 
small rudimentary tubercles (fig. 1, a and b). The areolae at the base and equator are 
narrow and deeply depressed, well spaced out from each other at the equator, and set 
closer together at the base. The scrobicular margin of one of the equatorial plates is 
surrounded by a circle of eighteen regular mammillated granules, larger than those filling 
the miliary zone (fig. 1, c) ; the boss is prominent, the summit smooth, and the tubercle 
moderately large and widely perforated (fig. 1, d). Above the equator the two or three 
upper tubercles entirely change their character, the areolae become extremely narrow or 
disappear (fig. 1, b), and the tubercle becomes a mere rudiment in the midst of the miliai-y 
granulation. The plate of this series nearest the equator, the third from the discal end, 
supports a very narrow areola (fig. 1, e) with a small tubercle, and on the two uppermost 
plates the tubercles are mere warty rudiments suiTounded by granules. 

The inter-ambulacral plates are large, convex, and inflated (fig. \, c, d, e) towards the 
middle, and slope gently towards the sutures, which are very well marked in this species. 

The miliary zone is wide and well developed, depressed in the middle and between 
the plates; the granules are fine, abundant, and homogeneous, and arranged in regular 
lines that radiate horizontally from the areolae to the borders of the plate (fig. 1, c, d, e), 
resembling in this respect C. subvesiculosa. 

The mouth-opening is small, and the peristome pentagonal ; the upper surface of the 
test is fractured, and the disc absent. M. Cotteau, who has figured a very complete 
specimen of this Cidaris, says that the periproct is pentagonal and star-shaped, and the disc 
solid and inflated, and larger than the peristome ; the ovarial plates are thick and angular, 
their internal surface smooth and marked by three facettes for articulation with the 
external row of anal plates ; the ocular plates are small, subpentagonal, deeper than wide, 
and not notched at the summit of the ambulacra. 

The spines have not been found in relation with the test. 

Affinities and differences. — This species resembles in so many important particulars 
the preceding species, that I hitherto considered it to be a conoidal variety of that form. 
M. Cotteau says this is one of the most curious species of Cidaris. Its form is in 



62 CIDARIS 

general inflated and sab-conical, its superior inter- ambulacral plates are entirely deprived 
of tubercles, the structure of its periproct and apical disc impart a peculiar physiognomy 
to it, and clearly distinguish it from its congeners. It is distinguished from C. sub- 
vesiculosa by its greater size, its inflated sub-conoidal form, its straighter ambulacra, and 
smaller and less regular granules. Its inter-ambulacral plates are more numerous, and 
the three uppermost plates in each column are entirely deprived of tubercles in the 
specimen figured by M. Cotteau, and they are small and rudimentary in the urchin figured 
in our PI. VIII, fig. 2. 

Locality and StratiyrapMcal position. — Collected from the White Chalk, where it is 
very rare. The fine specimen figured by Mr. Bone belongs to Dr. Bowerbaiik's collection. 
That figured by ]M. Humbert for M. Cotteau was collected at La Faloise pres Breteuil 
(Somme) ; in the Etage Senouien, where it is very rare. It belongs to M. Tombeck's 
collection. 



CiDARis PERORXATA, Forbes, 1850. PI. VII a, fig. 2. 



CiDAEis PERORNATA, Forbes, in Dixon's Geol. of Sussex, p. 339, pi. sxv, fig. 8. 

1850. 

— LOXGISPINOSA, Sorignet. Ours. Foss. de I'Eure, p. 19, 1850. 

— Sarthacensis, rf'Or%wy. Prod, de Tal. Strat, t. ii, p. 274, 1850. 

— perornata, Forhps, in Morris's Catal. of Brit. Fos.sils, 2nd edit., p. 74, 

li^54. 

— — Cotteau. Paleontologie Frangaise, t. vii, p. 274, pi. 1065, 

figs. 3—14, 1862. 

Test elevated, melon-shaped. Ambulacra nearly straight, narrow, depressed. Six 
rows of small granules, the marginal the largest and most regular, the inner small, with 
intermediate smaller ones. Inter-ambulacra wide, seven or eight large plates in each 
column ; areolai wide, circular, with a marginal circle of very small granules ; boss smooth 
or slightly crenulated ; tubei'cles small and perforate ; sutures well marked, depressed. 
Spines long, cylindrical, several-ridged ; ridges irregular towards the base, and serrated, 
the interstices granulated. 

Dimensions. — Height, one inch and eight tenths ; transverse diameter, two inches. 



Description. — The test of this fine urchin is high and melon-shaped, and reminds me 
of C. mawimus, from the Coral-rag of Germany. The ambulacral areas are narrow, 



FROM THE WHITE CHALK. 63 

nearly straight, and provided with six rows of small granules ; the marginal series are the 
largest, the inner ones are small, and between them are some still smaller granulets 
scattered about the area. The poriferous zones are only gently waved, the holes round, 
and placed transversely; there are fifteen pairs opposite each of the equatorial plates. 
The inter-ambulacral areas are very regularly formed ; the plates, about eight in each 
column, are large and uniform ; the areolae are wide and circular, and occupy the entire 
depth of the plate; the margin is surrounded by a circle of very small mammillated 
granules, about twenty-one in number, and well spaced out from each other ; the boss is 
not prominent, and only some of the summits are feebly crenulated, whilst the others are 
smooth. The tubercle is small, and deeply perforated (fig. 2, a, b). The miliary zone is 
wide, and depressed in the middle ; the granules are fine, homogeneous, and nearly equal- 
sized, and arranged in regular horizontal rows, which follow the angles of the median 
sutures. As the areolae occupy the centre of the plates, there is a considerable granular 
space between the ambulacral side of the areolae and the poriferous zones. The sutures 
are all very distinctly marked, and the median inter-ambulacral is much depressed. The 
peristome is sub-pentagonal and large. The spines are long, cylindrical, and sub-acumi- 
nated at the summit (fig. 4, a). The stems are provided with long, narrow spines, projecting 
at. intervals from many regular, longitudinal ridges, and having the interstices finely 
granulated (fig. 4, c). For the most part these spines are equally and uniformly disposed; 
sometimes, however, they lose their homogeneity, and vary in their height and in pre- 
serving a longitudinal disposition. The valleys between the ridges on the stem are 
throughout covered with fine, delicate, microscopic, sub-granular, longitudinal striae, which 
are only visible by the aid of a lens (fig. 4, c). The neck is without ridges and spines; 
the collar is long and finely striated, and separated from the stem by a distinct line (fig, 
4, b). The head is large, the milled ring prominent, with thicker striae than those on the 
collar, and the rim of the acetabulum is smooth (fig. 4, ^). . 

JJJinifies and differences. — The melon-shaped test, very regular inter-ambulacral areas, 
areolae and tubercles gradually increasing from the base to the upper surface, added to the 
long, slender spines, with prickly ridges, serve to distinguish this species from its congeners 
of the "White Chalk. The spines resemble those attributed to C spinigera, Cott., of the 
Neocomian stage, from the middle of France, but they manifest differences which are 
sufficiently distinctive of each. In C. perornata the spines arise from ridges at regular 
intervals, which are absent in C. spinigera. 

Locality and Stratigrapldcal 'position. — This species was collected from the White 
Chalk of Kent and Sussex. The specimens figured are from the cabinets of Dr. Bower- 
bank and Rev. T. Wiltshire. 

The foreign localities of this urchin are, according to M. Cotteau, Vernonnet, 
Giverney, Pinterville, ITouguemarre (Eure), Epagny (Somme), Tartigny (Oise), La Fleche, 
(Sarthe); where the spines are common in the Etage Senonien. 



64 CIDARIS FROM THE WHITE CHALK. 

msfo>y.—T\\e late Frederick Dixon, Esq., F.G.S., and Professor Forbes, first figured, 
in 1850, the test and spines of this species from tlie White Chalk of Sussex, and the latter 
described it as a new species under the name C. perornata. M. I'Abbc Sorignet described 
the spines which he collected in the department of the Eure imder the name C. loiif/ispiiwsa, 
and Professor d'Orbigpy those found in the Sarthe as C. Sarf/iacensis. As Professor 
Forbes first figured and described the urchin, and the other authors only described it, the 
name of the figured specimen is for this reason retained. 



CiDAiiis HiRTJDO, Soriffnet, 1850. PI. X, figs. 1 — 5 ; PI. IX. 

CiDARis HiRUDO, Soriffnet. Ours. Foss. de I'Eure, p. 17, 1850. 

— SCEPTUIFEEA, Forbes, in Dixon's Geol. of Sussex, p. 338, pi. xxv, figs. 32 and 33, 

— — var. spiNis TRUNCATis. 1850. 

— SULCATA, Forbes, in Morris's Catal. of Brit. Fossils, 2nd edit., p. 75, 183-1. 

— — Woodward. Mem. of Geol. Surv., Decade v, explanation of pi. v, 

p. 3, 1856. 
• — HIRUDO, Cotteau. Paleontologie Fran9aise, torn, vii, p. 2-1-4, pi. 1054, 

figs. 6 — 16. 

• 

Test, in general, of moderate size, sometimes large, slightly depressed equally at both 
poles ; ambulacial areas narrow, flexed, with six rows of granules at the equator, dimin- 
ishing to two at the apertures ; in the two external rows the granules are larger and mara- 
millated, in the inner rows they are very regularly disposed, but smaller and unequal; 
poriferous zones very narrow, depressed, and flexed, and formed of small round pores, 
the intervening septum having a slight divisional elevation ; inter-ambulacral areas wide ; 
columns with five or si.K large plates; areola moderate, depressed, margin elevated, and 
surroimded by a circle of mammillated granules, well spaced out apart ; boss with a 
smooth summit ; tubercle moderate in size and perforated, the areolae and tubercles in- 
creasing gradually in magnitude from the peristome to the upper part of the colimuis ; 
miliary zone depressed in the middle, and filled with equal-sized granides ; line of the 
sutures well marked thronghout. 

Spines elongated, cylindrical, subfnsiform ; stem enlarged at the middle, and tapering 
at the upper third, summit truncated and presenting a stellate figure ; the longitudinal 
ridges on the stem have a granuliform structure, and the intervening valleys are finely 
chagreened ; the neck is short, distinctly defined, and marked with longitudinal microscopic 
lines ; the head is small, the milled ring prominent, and the acetabulum has a smooth ring 
around the brim. 

i)M«e;Mvo«s.— Specimen PI. X, fig. 2 — height, nine tenths of an inch ; transverse 
diameter, one inch and four tenths. Specimen PI. IX — height, one inch, and three 
tenths; transverse diameter, one inch and nine tenths (?). 



THE 



PALiEONTOGRAPHICAL SOCIETY, 



INSTITUTED MDCCCXLVII. 



VOLUME FOE 1867. 



LONDON 




MOCCCLXVIII. 



A MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODERMATA 



FROM 



THE CRETACEOUS FORMATIONS. 



BY 



THOMAS WRIOHT, M.D., F.R.S. Edin., F.O.S., 

CORRESPONDING MEMBER OF THE BOYAL SOCIETY OF SCIENCES OF LIEGE, THE SOCIETY OF 

NATUEAX SCIENCES OF NEUFCIIATEL, AND SENIOR SURGEON TO 

THE CHELTENHAM HOSPITAL. 



VOLUME FIRST. 

PART SECOND. 
ON THE CIDARIDtE AND BIADEMAD.E. 

Pages 65-113; Plates IX, X, XII— XXL, XXI a, XXI b. 

LONDON: 

PRINTED FOR THE PAL/EONTOGRAPHICAL SOCIETY. 

1868. 



PRINTED EY J. E. ADLAKD, BARTHOLOMEW CLOSE, E.C. 



CIDARIS FROM THE WHITE CHALK. 65 

Description. — This beautiful Cidaris, formerly identified by Professor E. Forbes as a 
variety of C. sceptri/era, and afterwards catalogued by him as a distinct species, under the 
name C. sulcata, had been previously considered by the Abbe Sorignet, from its spines 
alone, as a new form, and described in 1850 as C. hirudo in his work on the ' Oursins 
fossiles du departement de I'Eure,' and this name has the priority. 

The test of the fine specimen belonging to Henry Willett, Esq., F.G.S., and 
fully illustrated in PI. IX., fig. 1 a, h, c, attains a moderate size, is inflated at the 
equator, and equally flattened at the poles. The ambulacral areas are narrow, sinuous, 
and band-like, forming prominent, wefl-marked segments in the test, filled with small, 
close-set, regularly arranged rows of granules ; there are six rows at the equator, 
four rows in the upper and lower thirds, and two rows only near the discal and 
oral apertures. The most prominent granules are in the external rows; they are 
slightly mammillated and extend throughout the entire area. PI. IX, fig. 3 b, is an equa- 
torial inter-ambulacral plate, with the ambulacral area attached, magnified three diameters. 
In the second row the granules are nearly as large, and extend through eight tenths of the 
area ; the third rows extend through the height of two large plates ; the granules are 
set very closely together, and regularly arranged in transverse rows. The poriferous zones 
are narrow, depressed and flexuous, fig. 2 (5 ; the pores are small and round, and the septum 
supports a small round granule ; the entire series of septal granules forms a moniliform 
line between the pores, which gives an apparent lateral extension to the width of the area ; 
and opposite one of the large plates there are twenty-three pairs of pores. 

The inter-ambulacral areas are wide, the plates composing them being deep and broad, 
five or six in each column ; the areolas are circular and moderately depressed ; they are 
closely approximated on the under side, wider apart at the equator, and still further apart 
above. 

PI. IX, figs. 1 and 3, PI. X, figs. 1,3, 3, show the character of t'he areolae ; the margin 
is slightly elevated (PI. IX, fig. 3 H) and encircled by a row of larger mammillated 
granules ; the uppermost plate in each alternate column has a rudimentary wart-like 
tubercle without areola (PI. IX, fig. 1 a, h) ; and in the other column the tubercle is small, 
but complete, and surrounded by a narrow shallow areola (fig. \ a, b) ; the base has a 
smooth flat summit, with only rare indications of crenulations ; those in fig. 3 b, are 
strongly drawn : the tubercle is large and perforated. The miliary zone is wide, depressed 
along the middle of the area, and along the transverse lines of the sutures : the granula- 
tions on the surface of the plates arc large in size and uniform in arrangement thereon. 

The apical disc (PI. IX, fig. 3 a) is large, and composed of five ovarial and five 
ocular plates ; the rhomboidal ovarials are widely perforated, and the cordate ocidars have 
small marginal orbits in the disc (fig. 3 c) ; the aperture is pentagonal, and there are in- 
dications of the outer series of small anal plates. 

The mouth-opening (PI. IX, fig. 3, and PI. X, figs. 1 a, and 3 b) is small, and the 
peristome slightly pentagonal ; in PI. IX, fig. 3, there is a rudiment of a jaw and tooth. 



66 CIDARIS 

The spines exhibit a considerable variation of form ; in some they are elongated and 
cylindrical, as in PI. IX, fig. 1 ^ ; or elongated and subfusiform, as in fig. 5, and PI. X, 
fig. 1 h, and figs. .5, 6. In all the stem is slightly enlarged in the middle, and tapers 
towards the upper third. The surface in some specimens is sculptured with fine longi- 
tudinal lines, as in PI. IX, fig. 1, and Pi. X, figs. 1, 4, 6; or has granulated ridges with 
intervening valleys, as in PI. IX, fig. 5, and PI. X, fig. 5. The summit is truncated more 
or less in all the specimens, and exhibits a stellate figure with several central convexities as 
in PI. IX, figs. 4 a, and 4 c, 5, the radii being formed by the development of the longi- 
tudinal ridges. 

In the more finely sculptured spines the longitudinal lines on the stem have a granuliform 
structure; the intervening valleys are finely shagreened throughout, and provided with 
delicate subgranular striae. The neck is short, distinctly defined, with a finely sculptured 
line above the ring (PI. IX, figs. 4, 5, PI. X, figs. 1, 4, 6). 

The milled ring is moderately prominent, with coarser lines than those on the neck ; the 
articular cavity is smooth, or has some feeble crcnulations on its margin (PI. IX, figs. 4, 
5, PI. X, figs. 1, 4, 6). 

Affinities and Differences. — This form has long been considered to be a mere variety of 
C. sceptrifera ; the proximal discal plate, liowever, has generally a rudimentary tubercle 
of larger size and rounder shape than that found on C. sceptrifera. The second discal 
plate (counting downv^'ards) has the upper three quarters of the boss much more strongly 
crenulated than in the other species (at p. G4 the upper bosses of C. hirudo were 
accidentally stated to be not crenulated). The large size of the areolas, their comparative 
continuity, the prominent raammillated granules upon their circumference, and the 
circumstance of the highest areola bearing a perfect tubercle being distant from the anal 
margin by not more than half its diameter, easily separate this species from C. sceptrifera, 
in which the areolas have more sloping borders, smaller and more numerous mam- 
millatcd granules, and in which the highest areola bearing a perfect tubercle is generally 
distant from the anal margin by the length of its diameter. The spines are much 
shorter and more uniform in diameter than in C. sceptrifera, having their greatest 
swelling midway between the acetabulum and summit, instead of towards the former ; 
their extremities are more truncated, often becoming stellate, as on Plate IX. fig. 
4 c; their surface is covered with longitudinal ridges, armed with very much shorter 
piny projections, often almost obliterated ; the collar is shorter, and the acetabulum is 
marked with stronger crcnulations. C. hirudo is a rather small species, less than 
C. sceptrifera, and not so common. An average size wiU be about one inch and one 
tenth in transverse diameter, height six tenths, length of spine one inch, greatest 
diameter of spine three twentieths. 

Locality and Strafir/raphical Position. — The specimens I have examined have been 
collected from the White Chalk of Sussex and Gravesend. In France M. Cotteau 
gives the following localities where this Urchin is common — the Etage Cenomauien, de Havre 



s 



FROM THE WHITE CHALK. 67 

(Seine-Inferieure), Fourneaiix la Madeleine (Eure), Saint-Parres pres Troyes (Aube), Eltage 
Senonien Inferieure, Etretat (Seine Inferieure), Tartigny (Oise), Chalons-sur-Marne 
(Marae). 

History. — The Abbe Sorignet in 1850 described a spine of this species under the 
name C. hirudo. The same year the test was well figured with its spines attached 
by the late Mr. F. Dixon, and described by the late Professor Forbes as C. sceptrifera 
var. spinis trtmcatis ; subsequently it was found that Mr. Dixon had given it the MS. 
name C. sulcata, under which name it appeared in the second edition of the ' Catalogue of 
British Fossils/ and in Dr. Woodward's notes on Cidaris in the Fifth Decade of the 
'Memoirs of the Geological Survey.' The Abbe Sorignet's name has been properly 
retained by M. Cotteau in his continuation of D'Orbigny's Paleontologie Fran^aise. 

Cidaris Dixoni, Cotteau. PI. XI, fig. 4 ; PI. XII, fig. 6. 

CiDAKis. Bixon, Geol. of Sussex, p. 339, pi. xxiv, fig. 25, 1850. 

CiDABis Dixoni, Cotteau. Paleontologie Fran9aise, torn, vii, p. 238, pi. 1051, fig. 78, 1862. 

The test of this fine Urchin is unknown. 

Description. — Spine very large ; stem thick, oblong, glandiform, much enlarged in the 
middle, and tapering towards the neck and apex ; the lower part is covered with convex, 
scale-like plates, arranged without much regularity ; in the middle part they are larger, 
and have much the same character ; at the upper third they are less closely set together, 
become ridged, and form granulated lines, which pass towards the summit ; the intervening 
valleys are covered with fine longitudinal lines. 

The neck is short and smooth, altliough there are traces of longitudinal lines ; the 
milled ring is not prominent, and the articular cavity indicates a small tubercle ; the rim 
of the acetabulum is smooth. 

Dimensions. — Length of the entire spine, from acetabulum to apex, l^ths of an inch ; 
length of neck and head ^^ths of an inch; length of stem Ijiths of an inch; thickness of 
stem, at widest part, ^ths of an inch. 

Locality and Stratiyraphical Position. — Found in the Grey Chalk near Folkestone 
by the Rev. T. Wiltshire, F.G.S., whose cabinet contains a very fine specimen. Mr. 
Dixon's type, which formed the subject of fig. 4, PI. XI, is in the collection of Henry 
Willett, Esq., F.G.S. M. Cotteau records two specimens from the Etagc Cenomanien, 
at Havre (Seine Inferieure), where it is very rare. 

Cidaris pxeracantha, Agassiz. PI. XI, fig. 5 ; PI. XII, fig. 5. 

CiDAKIs PLERACANTHA, Jyassi:. Catal. Syst. Ectyp. Foss., p. 10, 1840. 
— — Sorignet. Oitrsiiis foss. dc I'Eure, p. !, 18.")0. 



68 CIDARIS 

CiDABis PLEEACAKTHA, IfOrhigny. Prodrome de Pal. Strat., t. ii, p. 2/4, ^Et. 22, 1850. 

— — Dixon. Geology of Sussex, tab. xxiv, fig. 23, 1850. 

— — Besor. Synopsis des Echinides foss., t. vi, fig. 7 — 10, 

p. 14, 1855. 

— — Woodward. Mem. Geol. Siirv. Decade V, Expl., pi. v, 

p. 3, 1856. 

— — Cotteau. Paleontologie Franc., Ter. Cret., torn, vii, tab. 1075, 

fig. 1 — 13, p. 310, 1865. 

Test unknown. 

Bescrijjtioii. — Spine very large, inflated, pyriforra, with an obtuse and unequally 
rounded summit ; stem ornamented with longitudinal striae, very fine or subgranular, and 
visible near the lower part, the upper part is smooth ; the stem suddenly contracts to form 
a very short neck and a small head ; milled ring a little elevated and marked by fine lines ; 
acetabulum small with a smooth ring. 

Spines of this species are very rare indeed in the English Cretaceous rocks. The 
specimens collected at Meudon, near Paris, and at Civieres (Eure), vary much in form 
and dimensions; some are short, thick, or pyriform, and have the stem round or depressed 
at the summit, or inflated, subcylindrical, accuminated, or truncated ; and in a large 
specimen before me from France the stem is bifiu'cated. 

Locality and Stratigraplucal Position. — Mr. Di.xon's specimens were said to have been 
found in the Grey Chalk of Sussex. It occurs also in the Lower Chalk of Dorking. The 
specimen figured, Plate XII, fig. 5, in the Cabinet of J. R. Capron, Esq., F.G.S., came 
from that locality. 



CiDARis Earringdonensis, Wright. PI. II, figs. 6, 7, and 8 a, b, c. 

Test known only by isolated plates. 

Description. — Spines long, slender ; lower portion of the stem smooth, upper portion 
ornamented with longitudinal rows of granules forming tuberculated lines or ridges in 
different spines, and terminating in a star-shaped summit at the apex. The proportional 
length of the smooth to the granulated ornamentation of the stem varies in different spines 
— in some w^ith a long smooth portion the line of separation is defined by an annular 
elevation, in others with a shorter smooth portion the granulations arise without any such 
ridge. The valleys between the longitudinal ridges have a finely shagreened surface ; the 
head is moderate in size, the milled ring prominent, and the small acetabulum has a 
well-defined marginal rim. 

The isolated plates of the test are much worn by friction ; the primary tubercle is 
small, the areola wide and smooth, and the margin surrounded by a circle of large well- 
defined granules, resembling the plates of Cidaris vesiculosa. 

Affinities and Differences. — The spines of Cidaris Farringdonensis differ so much from 



FROM THE GREY CHALK AND FARRINGDON BEDS. 69 

all other forms at present known that they cannot be mistaken for any other species, the 
long smooth lower portion of the stem forming such a conspicuous specific character of 
this spine. 

StratiprqjJiiccd Position. — The specimens I have figured were collected from the 
Sponge-gravel near Farringdon, in Berkshire, associated with Pscudodiadema rotulare, Ag., 
Hyposalenia Wri(/htii, Desor, Hyposalenia Lardyi, Desor, Salenia areolata, Wahlb., and 
two new species of Echinobrissus, together with the Amorphozoa and MoUusca that 
characterise this remarkable formation. 

My kind friend the Rev. T. Wiltshire, F.G.S., at my request, has contributed the 
following additional notes on some rare tests and spines of Cidares in his collection. 
These are figured in Pis. XH and XHI. 

" In the course of last year you expressed the desire that I should send you some 
notes in reference to the fossils figured in Plates XH and XHI of your Monograph on 
the Cretaceous Echinodermata. In compliance, therefore, with your wish, the following 
remarks are forwarded, to be used or rejected as may seem most fitting. 

" The Urchin drawn in figure 1 , Plate XII, is probably a new species intermediate 
between Cidaris sceptrifera and C. subvesiculosa. I would suggest it should be named 
C. intermedia ; it may be thus defined : — 

Cidaris intermedia, Wiltshire. PI. XII, figs. \ a,\b. 

"Test moderately large, inflated; ambulacral areas narrow, depressed, flexuous, with 
six rows of granules in the middle, the outer two the largest, diminishing to four rows 
above and below ; poriferous zones winding, narrow, depressed, at the ambitus about the 
same width as the semi-ambulacral areas, narrower above, wider below ; interambulacral 
areas wide, plates large, five in a column ; areolas proximate, deep, suboval, with an 
elevated slightly overhanging scrobicular margin, encircled by a series of small granules, 
equal in dimensions to those of the outer row of the ambulacral areas, bosses not prominent, 
summit smooth, tubercle moderate in size, perforated; proximal discal plate in each 
column with a rudimentary tubercle, in a circular area ; miliary zone narrow, filled with 
small equal-sized granules depressed along the line of sutures ; apical disc wide, of the same 
diameter as the peristome ; ovarial plates thick ; jaws stout, triangular ; spines long, slender, 
cylindrical, slightly tapering, surface marked by regular longitudinal rows of spiny 
projecting granules, the intervening space finely shagreened. 

" Dimensions. — Height /^ths of an inch (the specimen being very slightly crushed) ; 
transverse diameter 1 inch and /„ths. 

" Description. — The test of this Urchin is circular, and is equally depressed at both 



70 CIDARIS 

poles ; the ambulacra! areas are narrow and flexuous, rather more so than in C. sceptrifera, 
rather less so than in C. subvesicidosa ; granules six in number at the ambitus, diminishing 
to four at the poles ; the central rows at the upper and under surfaces minute and irregular ; 
the four central rows at the ambitus composed of granules of less size than those of the 
exterior rows, consisting of greater numbers, and somewhat irregularly arranged ; the 
poriferous zones are narrow and depressed, and follow the flexures of the areas ; the pores 
are round, closely situated, and disposed obliquely ; there are eighteen pores (thirty-six 
in aU) opposite one of the largest plates ; the interambulacral areas are very wide, 
five to six plates in a column ; the areolas are wide, slightly oval (the minor axes being 
towards the poles) at the ambitus, circular at the peristome and anal margins, and are 
svu-rounded by an undercut overhanging border, encircled by a series of about twenty 
granules, each raised on a distinct shield-like maramillated plate ; the areolas at the 
equator have their borders separated from the upper and under plates by a small interval 
occupied by about five sets of granules ; at the under surface these granules are absent, 
and the scrobicular margins are in contact ; at the upper surface the granules increase in 
number ; the penultimate plate of the anal surface has an areola rather larger than that 
below ; the final plate has a rudimentary tubercle in a small circular areola, this last plate 
is covered with granules ; the boss is not prominent, its summit is smooth and without 
crenulation, the tubercle is moderately large and perforated ; the miliary zone is narrow, 
and the granules are so arranged as to present the appearance of radiating from the 
scrobicular margin towards the sutui'es ; they are much smaller than those surrounding 
the areolas ; the surface on which they are studded dips towards the sutures, causing the 
latter to be clearly defined. The apical disc is of the same size as the mouth-opening 
and in the specimen figured is six tenths of an inch in diameter ; the plates with which 
it is furnished are large, and covered with granules ; the mouth is furnished with strong 
jaws, shown in the plate. 

" The spines are long, cylindrical, and very slightly tapering, covered with small, 
strong, equal-sized granules, the points of which project outwards. They are 
arranged in ten regular longitudinal ridges, with a sulcus between them covered with 
a very fine granulation. The spiny granules continue to within a tenth of an inch of the 
collar ; the neck is very short and smooth, the head moderately large, cone-shaped, and 
longitudinally striated with numerous fine lines ; the rim of the acetabulum is very finely 
crenulated. The length of the longest spine, that of the ambitus, is one inch and eight 
tenths ; it is slightly broken at the extremity, and therefore would, if perfect, be rather 
longer ; its diameter is one tenth of an inch ; the short spine, which is unbroken (seen in 
the right hand of the plate), has its extremity suddenly expanded. 

" Affuiliies and Differences. — Cidaris intermedia, in the general appearance of its test, 
closely approaches C. sceptrifera and C. subvesiculosa ; it differs from the former in the 
scrobicular margins from the ambitus to the peristome being in contact, or not separated by 
more than one granule, — in the more narrow miliary zone, — in the lesser number of rows 



FROM THE WHITE CHALK. 71 

of granules in the anibulacral areas at the ambitus (C. scepfriferam specimens of the same 
size as that under consideration having eight at the equator, whilst this species has six), — 
in these granules being more irregularly disposed and more crowded together, — in the 
proximal discal plate being marked with a more prominent tubercle, and in its shape 
being less elongated, — in the areolas being relatively larger, — in the spines being uniformly 
cylindrical instead of fusiform, and of much less diameter, — and in the serrated ridges of the 
spines being fewer, wider apart, and continuous the whole length, whilst in C. sceptrifera 
some of the ridges cease at the widest part of the spine. C. intermedia differs from 
C. mhvesiculosa in the scrobicular margins of adjacent plates being less widely separate, 
— in the granules on the margins of the areolas being more distant, — in the sutures of 
the miliary zones being less marked, — in the miliary zones being smaller, — in the spines 
being of less diameter, with less numerous ridges, and apparently shorter (some 
spines of C. mhvesiculosa, of a test of equal dimensions, reaching a length of three inches), 
— and in the plates presenting a flatter and less tumid appearance. 

" Locality and Strati graphical Poszif/ow.— Collected from the White Chalk of Sussex, 
apparently from the base of the Chalk-with-fiints ; rare. The specimen figured, Plate XII, 
fig. 1 a, is of the natural size. Fig. 1 h, one of smaller spines magnified, length 1 inch, 
diameter ^th of an inch. 

"Additional Notes on CIDABIS CLAVIGUBA, Koniff. (Seep. 48.) 

" Very marked as are the variations in the general aspect of the spines of C. clavigera, 
it will usually be found that a single and prevailing form is connected with each indivi- 
dual test. On PL XIII are drawn the tests and spines (figs.ll a, 3 a, 4 a) of three speci- 
mens, in which the spines attached to the tests are tolerably uniform in shape in each case 
collectively, yet are dissimilar when viewed by groups, those of fig. I a being all cla- 
viform, those of fig. 3 a being all medially constricted, those of fig. 4 a being all fusiform. 
The same remark holds good in other examples not drawn on the plate. I have now 
before me sixteen specimens of C. clavigeru, with the spines attached, in all of which speci- 
mens, although as a general character each company of spines has a club-shaped or approxi- 
mately club-shaped contour, there is so great a variableness among the different groups 
that if in any group the two extremes in form were to be compared apart from the test 
they could easily be mistaken for different and distinct species ; some (No. 1 of the Table 
on page 72) being wholly cylindrical, these by easy gradations seen in sets of forms passing 
on so as to become pear-shaped (No. 4), next taking up the ordinary clavigerous type 
(Nos. 6, 7, S), and ending with those having the medially constricted outline (No. 10). 

" I append woodcuts of some of these varieties, giving their dimensions in tenths of 
an inch, and also the diameter (major axis) of the test to which they belong. The 
measurements of the spine in each case have been derived from a specimen which in its 
natural position would have been affixed to the ambitus. 



72 



CIDARIS 



" Table showing variation of form in the spines of Cidaris dav'igera. 



Total 



Ambitus Spine, characteristic of the . ,, . 
1 !• ,-1 11 /- .1 lenprth of 



general form of the wliole of Ilie 
spines attached to any individual 
test of C. clavigera, nat. size 



Almost unif'oimly 
cylindrical raid 
slender; very un- 
usual form of 
spine. 

1. 



iiii' 



Almost unifornilv 

cvlindrical, bnt 'iiilll 

i ' • • ! ;^ 

not slender; very 



•iili^l 



Sliglillj' tapering ; 
rare. 

3. 



Pear-sliaped, longi- 
tudinal section 
elliptical ; rati er 

rare. 

4. 




Pear-sbaped, longi- 
tudinal section 
ovate; rather 

rare. 




longest 

ambitus 

spine. 



Diameter 

of spine at 

neck. 



M 



Diameter 

at greatest 
thickness. 



Length of 
neck before 

swelling 
commences. 



■3 



Form of apex. 



Hemisphe- 
rical. 



Hemisphe- 
rical. 



Subacute. 



Subacute. 



Sub-beniisplie- 
rical. 



Diameter of test 
at ambitus. 



Uncertain, 
about I'O 



Uncertain. 



About 'G 



I-l 



1-2 



FROM THE WHITE CHALK. 



73 



" Table showing variation of form in the spines of Cidaris davigera — continued. 



Ambitus Spine, characteristic of tlie 
general form of tlie whole of the 
spines attached to any individual 
test of C. clavigera, nat. size. 



Club-shaped, stem 

slightly tapering ; v. .m 
common. 
6. 




Club-shaped, stem (illji 
cylindrical; com- "*'*' 
mon. 
7. 




Club-shaped, por- (■(iiiij 
tion nearest the 



apex constricted ; 
common. 
8. 



Club-shaped, por- 
tion nearest the 
apex constricted ; 
rather rare. 
9. 



Constricted at about 
half the length; U|.(jj 
very rare. 
10. 



Total 

length of 

longest 

ambitus 

spine. 



1-3 



1-0 



1-3 



1-0 



Diameter 

of spine at 

neck. 



Diameter 
at greatest 
thickness. 



Length of 
neck before 

swelling 
commences 



Form of apex. 



Hemi- 
spherical. 



Hemi- 
spherical. 



Hemi- 
spherical. 



Hemi- 
spherical. 



Acute. 



Diameter of test 
at ambitus. 



About rO 



1-1 



11 



10 



74- 



CIDARIS 



" From the above Table it will be seen that this variation in form is independent of the 
size of the test, and is dependent rather npon some peculiar law in the formation of the 
spine, or some cause which has contributed to produce a greater development of calcareous 
matter in one part than in another. In flints which contain the spines of C. cla- 
vigera a fracture passing through the spine will often exhibit this growth very beauti- 
^^'^^ 1- fully; thus, in the woodcuts (fig. 1), whilst an earlier form of 

the spine is clearly defined, the subsequent addition of 
material is also manifested by the change of tint. The same 
efiect can also be observed in longitudinal sections of the 
ordinary spines, a difi'erence of density and of hardness in 
the whole or parts of the enveloping layers being very 
apparent. 

Sections of body-spines of C.clmigera 
in flint. 

" In C. claviffera the difi'erence between the spines of the peristome and of the ambitus is 
more marked than in most of the other species of the Cidarid^ of the Upper Cretaceous 
group. The woodcuts (fig. 2) drawn from the spines of the tubercles adjacent to the 
mouth, and magnified four diameters, show that their apex is more acute, their ridges fewer, 
and their body more elongate-ovate than in the larger spines of the ambitus. The spines 
of the granules (fig. 3) are also dissimilar, being longitudinally striated, contracted at 
intervals, having almost parallel sides, and being in transverse section ovate. 




Fig. 2. 




Spines of C. clavigera from tlie tubercles aiijacent to the peristome ; 
magnified four diameters. One spine lias four sen-ated ridges, 
tiie other six. 



Fig. 3. 



Spine of C. clavigera from tlie granules on the 
margin of the ambulacral areas ; magnified 
eight diameters. 



" The spines in their original condition appear to have been tinted with parallel bands 
of colour, perpendicular to the axis. In several examples now in my cabinet the apex of 
the spine shows evidence of this peculiarity ; but in one specimen in particular (a test to 
which the spines are attached) that circumstance is so marked and is so persistent (the 
base and apex of the body of the spines being specially affected) that it can hardly be the 
result of accident. 

" The common longitudinal perforations in the outer layer of the spine alluded to at 
p. 50 seem to have been chiefly due to disease or to some difi'erence in structm-e which 
caused those parts, now empty, to decay with greater facility in one direction than in 



FROM THE WHITE CHALK. 75 

anotliei". A transverse section of spines so affected proves that the canals are of neither 
uniform length nor dimensions, some being of greater extent and more open than 
others . 

" The central perforation not unusual at the apex of some spines, seems also due to 
disease or to parasitic borings, and will often be found to extend downvi^ards as far as 
the acetabulum. This is the case with the spine drawn in PI. V, fig. 6. A portion of the 
surface of this spine having been cai'efully removed subsequent to the drawing being made on 
the plate, the cavity apparent at the apex was seen to extend through the whole length of 
the body, unaltered in size ; just below this point it suddenly contracted in a circular 
curve (similar to the base of the perforations made by a Pholas) as though to avoid break- 
ing through the walls of the neck ; at the lower point of the circular excavation the opening 
appeared again, only with a very much less diameter, and extended as far as the articular 
cavity, through which it passed. Another spine open at the apex, when cut lengthways, 
gave the same result (of a continuous tube, of two different diameters), except that the 
opening, which extended almost as far as the acetabulum, did not pierce it, but passed 
outwards in a transverse direction. 

" The test of C. davigera varies in the proportions of its parts from youth 
to age ; my smallest example, five tenths of an inch in width, differs consider- 
ably in appearance from my largest, which is one inch and seven tenths in 
width. Comparing these two it is seen that the tubercles in the former are 
relatively larger than in the latter ; that the granules of the miliary zone are in 
the former almost as large as in the latter ; that the number of plates are the same 
in both ; that there is an oval rudimentary tubercle in the uppermost plate of the 
anal side in the largest specimen ; that the areolas of the two superior tubercles 
of the anal side are in the smallest example separated by only three granules, including 
those of the scrobicular margin, whilst in the largest example there are fourteen. Both 
specimens have four rows of granules in the ambulacral areas at the ambitus ; in the 
smallest they are of equal size and equally disposed, in the largest the two interior are 
much smaller than the two exterior, more numerous, and crowded together. These dif- 
ferences have a tendency to cause the two specimens, when placed with the anal side 
uppermost, to appear very dissimilar, particularly in the region of the miliary zone. 
Of these two specimens the smallest is much below and the largest much above the average 
size. 

" Spines of C. davic/era are sometimes, but very rarely, found as far down as the 
middle of the flinty Chalk ; the proper horizon of C. davigera is above this part. 

" Figures 1 a, 1 (5, 2, 3 a, 3 (5, 3 <?, 4 a, ^h,^ a,h b, PL XHI, are from the Upper 
Chalk of Bromley, in Kent. 



76 CIDARIS 



"A.DDITIONAL Note on CIDJBIS FUBOBNJTJ, 'Forbes. (See p. 62.) 

" This Cidaris is the largest of all the Cretaceous Cidarid/e ; portions of a full-grown 
specimen now before me, containing fom- complete columns of plates in contact, give the 
following dimensions for the test — height, two inches and two tenths ; transverse diameter, 
two inches and one tenth. The spines, like the body, also exceed those of all other 
species. In a mass of spines of C. perornata from my cabinet, which are all one tenth 
of an inch in diameter, is one which, although deficient of a portion of its apex, measures 
in the remaining part of its length four inches and six tenths — this length is by no means a 
maximum. The number of the plates and the form of the spines appear to have rendered 
perfect examples of the test with spines attached exceedingly rare. Separate plates and 
groups of broken spines are plentiful ; complete columns of plates uncommon. Small 
Ostrece are occasionally found affixed to the spines. 

" The test, when full-grown, has, in the ambulacral areas, eight rows of granules at the 
ambitus ; of which rows the two exterior are the largest and most evenly disposed, the 
six interior are more numerous, of less size, and not so regularly arranged ; at the mouth- 
opening there are six rows, at the anal four ; the second discal plate has nineteen pairs of 
pores in the poriferous zone ; the proximal discal plate in each column has a rudimentary 
tubercle and an elongate obsolete areola. The granules of the miliary zone are of two 
sizes, the smallest of which occupy the spaces between the largest. In specimens of the 
test of the usual size the first, second, and third of the plates, reckoning downwards from 
the anal opening, have the upper half of the boss crenulated. The spines belonging to 
the granules of the scrobiciilar margins are flat and somewhat fan-shaped; they are 
covered with minute strise, which converge from the circular base (in which there is an 
acetabulum) towards the smaller apex ; length two tenths of an inch, greatest width one 
twentieth. The jaws of a full-grown specimen do not greatly difier in outline from those 
of other species ; they are half an inch in length. 

" Cidaris 2ierornata is tolerably common in the Upper Chalk; it appears to commence 
(where it is rare) in the middle of the flinty Chalk. 



" Additional Note on CIBABIS DIXONI, Cotteau. (See p. 07.) 

" All the spines of this species hitherto found are of considerable size, and are clavi- 
form, and inflated ; the apex is acute ; the surface covered with numerous granules, which 



FROM THE GREY CHALK. 77 

are large and elongate on the upper half of the body, pointed at the apical region, 
circular on the lower half of the body, diminishing in area as they approach the neck, 
and ceasing at that part, arranged in rows gradually increasing in number from 
the apex to the greatest diameter, and afterwards more closely and less regularly 
deposited ; the neck smooth, short, and very much contracted ; the milled ring is slightly 
prominent, covered with fine longitudinal striaj ; the head smooth. 

" The spines of C. Bixoni occur at the base of the Lower or Grey Chalk in the cliffs 
between Folkestone and Dover, in the band containing the spinous Ostrea carinata, Sow. 
(M.C., tab. 365, fig. 1), in company with C. Bowerhankii ; they are, however, very rare. 
The same species is found occasionally in the " Coprolilic Bed " of Cambridge, a deposit 
containing rolled fossils from the Lower Chalk, Upper Greensand, and Gault formations. 
The specimen figured in PI. XH, fig. 6, and obtained from the Coprolitic Bed of 
Cambridge, is identical in all respects with the Folkestone examples, except that the 
surface is more worn, and appears to have been subjected to much friction ; the width of 
the Cambridge specimen is seven tenths of an inch, length of body one inch. The 
total length of spine (measured from a specimen in perfect condition in my cabinet), 
from Folkstone is one inch and four tenths ; greatest diameter (midway between apex 
and edge of acetabulum) seven tenths ; length of head and neck three twentieths ; 
diameter of neck three twentieths. 

" The test of this Cidaris has not at present been discovered ; it would appear, however, 
judging from the analogy of its spines with those of C. Bowerbankii, that it must have 
much in common with the latter, except size ; perhaps it may be an aged form of 
C. Bowerbankii. 



" Additional Note on CIDABIS BOWERBANKII, Forbes. (See p. 45.) 

" Li this species, as in others of the Cidares, the form of the spine varies according to 
its position on the test ; those at the peristome are tolerably cylindrical, with an acute 
apex ; those at the ambitus are inversely conical, with the apex less acute, and those at 
the anal margin have the body inflated and the apex somewhat obtuse. The peri- 
stome spines have the surface covered with coarser granulations than is the case with 
those which occur on the opposite side. At Southeram Pit, near Lewes, Sussex (Lower 
Chalk), tests with the spines in situ are occasionally found. In my cabinet is a specimen 
from Southeram Pit nearly perfect, in which almost the whole series of spines, from the 
anal to the oral region, are in position, and in which the variation of form in these spines, 
according to their situation, is well exhibited. From this specimen were drawn the figures 
shown in the woodcuts fig. 4 a — d, which are twice the size of the originals ; a is the spine 



78 



CIDARIS 



in connection with the tubercle adjacent to the anal margin ; b that on the next tubercle, 
counting downwards ; c that beneath b ; and c/that below c, on the tubercle which is the third 
from the peristome : a is in length five tenths of an inch, in diameter three tenths ; d is in 
length two tenths of an inch, in diameter one twentieth. The test from which these spines are 
derived is five twentieths of an inch in height, and nine twentieths in transverse diameter. 

Fig. 4. 





a. It. c. d. 

Spines of Cidaris Bowerhankii ; magnified two diameters. 

" Several of the spines of this species from different localities are figured on PI. XIII ; 
figs. 9, 10, and 11 are from Folkestone, figs. 13 and 14 from Cambridge, S from near 
Arundel, from which last-mentioned locality also come the plates of C. dissimilifi, figured 
PL XIII, figs. Q> a,Qb. In all these a certain variation in general form is very perceptible. 
" Cidaris Bowerhankii has great affinities in its test with C. davigera, but is always 
much smaller in size. It is a very rare species. The horizon of C. Bowerbankii at 
Folkestone is just above the Upper Greensand. 

" At Folkestone, in company with the spines of C. Bowerbankii, occur globose spines 
with a short neck, and having tlie body covered with coarse spiny projections arranged 
longitudinally. They are drawn of the natural size in the woodcut fig. 5 ; they appear 
to differ from C. velifcra, and arc perfectly distinct from the spines of C. Bowerbankii. 

Fig. 5. 




a. i. c. 

Spiues of a Cidaris from tlie Lower Clialk at Folkestone ; natural size. 



" Additional Note on the CIDARES from the Red Chalk. (See p. 44.) 

" In the thin red-coloured band met with at Hunstanton, in Norfolk, and in the lowest 
of the pink-coloured beds at Speeton, in Yorkshire, occasionally occur elongate, cylindrical 



FROM THE RED CHALK. 79 

spines, which do not exactly agree with those previously refeiTcd to in this Monograph ; 
four of these are drawn on PI. XH, of which figs. 7, 8, and 9 are from Hunstanton, and 
fig. 10 from Speeton. They may be divided into three classes — (a) slender, having few (ten 
to sixteen) longitudinal ridges, with a prickly border, PI. XH, figs. 7 and 9 ; (/3) thick, 
having numerous longitudinal ridges, with the prickles almost obliterated, PI. XH, fig. 10; 
and (7) slender, without ridges, but with an occasional projecting prickle. 

" The drawing, PI. XH, fig. 7, represents a magnified view (the natural size being 
depicted by a black line) of the expanded extremity of a spine with twelve ridges, not 
unlike in its general character that to be met with in some forms of the spines of 
Cidaris GauUina, but differing from the latter in the valleys between the ridges being 
covered with very fine longitudinal lines, instead of being marked with fine granulations. 
Fig. 9, with ten ridges, is marked also by the fine longitudinal striae, and the absence of 
granulations in the valleys ; the lines of spiny projections or prickles are thinner, more 
conspicuous, sharper, and less numerous than in the spines of C. GauUina ; it is very 
slightly tapering ; the fragment preserved measures an inch in length, and must when 
perfect have been at least two inches ; in general aspect it bears a strong resemblance to 
C. subvesiculosa from the Upper Chalk. 

" The spine fig. 10 « (natural size), and fig. 10 1^ (a portion magnified) is found both at 
Speeton and Hunstanton ; the specimen figured, which was from Speeton, and is not 
quite perfect, measures one inch and a half in length, and is two tenths at its greatest 
diameter ; the body of the spine increases very gently in diameter for a short distance 
from the acetabulum, and then as gently diminishes j the margin of the acetabulum is 
crenulated, a double milled ring surrounds the head, the neck is short and smooth, and 
the body is marked by about thirty longitudinal ridges, which are crowned by small and 
obtuse spiny projections. The valleys between the ridges are covered with fine longi- 
tudinal striae; the general aspect is that of a spine of C. dissimilis, but the latter 
generally has the spines much more slender. 

" Fig. 8, from Hunstanton, is only a fragment, half an inch in length, and one tenth of 
an inch in diameter; it is uniformly cylindrical, with the surface quite smtooh and 
without stria; ; arising from the smooth surface are stout prickles, like thorns, which are 
repeated in longitudinal lines at about the distance of the tenth of an inch apart from 
each other. It is a very peculiar spine, totally distinct from all those of the Cretaceous 
species, and mostly resembles the spine of C. perornala from the Upper Chalk ; in the 
latter, however, the prickles arise from a small longitudinal ridge, and are not isolated and 
unconnected. The same form of spine occurs at Speeton. In the ratio of frequency, 
the form a is more common than that of /3 ; and the forms a and /3 are more conunon 
than that of 7, which is very rare." 



80 CLASSIFICATION OF THE. 

Tamilij 2. — HEMiciDARiDiE. (Not yet found hi British Cretaceous strata.) 

Family 3. — DiADEMADiE. 

This Family inchides large and small Urchins having a thin, circular, pentagonal, and 
subpentagonal test, more or less depressed on the upper surface, and flat at the base. 

The ambulacral areas are wide and straight, with two rows of primary tubercles, often 
as large and numerous as those of the inter-ambulacral areas. 

The poriferous zones are narrow, almost always straight, and sometimes subflexuous ; 
the pores are unigeminal^ bigeminal, and trigeminal in their arrangement in different genera. 

The inter-ambidacral areas are in general twice the width of the ambulacral, and occu- 
pied, at the equator, with two, four, six, or eight rows of primary tubercles, which diminish 
gradually in numl)er near the poles. The bosses of all the tubercles are small ; their 
summits, in general, are crennlated, sometimes uncrenulated ; the tubercles are small, in 
general perforated, in Cypliosoma imperforate ; they are in general a little larger than those 
of the ambulacra; but are often of equal magnitude in both areas. 

The apical disc is small, and situated opposite to the mouth ; it is composed of five 
ovarial and five ocular plates ; the anterior pair of ovarial plates are a little larger than 
the posterior pair, and the right antero-lateral plate, with a small, spongy, madreporiform 
body on its upper surface, is the largest ; the vent is round or oblong, and generally in 
the centre of the disc ; the ocular plates are very small, and distinguished with difficulty. 

The mouth-opening is in general large and decagonal, and the peristome divided into 
ten lobes by deep notches ; the jaws in general are large and powerful. 

The spines in existing genera are long, slender, and tubular, sometimes three 
times as long as the diameter of the test.^ In the fossil extinct genera they rarely attain 
the length of the diameter of the test, and are short, stout, and solid, except in Hemipedina, 
which have long hair-like spines. The long tubular spines of living Diademas, and a rare 
form from the Cretaceous rocks, are encircled by spiral verticellate processes, or fringe- 
like scales, PI. XIV, fig. 2, whilst the surface of the solid spines of Pseudodiademas is in 
general covered with fine longitudinal lines ; neither prickles or asperities being developed 
on their stems. 

Lamarck divided the genus Cidaris of Klein into two sections, " Les Turbmis" and " Les 
Diadhnes " these were afterwards by Dr. Gray" erected into genera ; the Cidaris radiata, 
Leske, constituting a third type, formed his new genus Astropyya. The genus Cidarifes of 
Lamarck was considered to form a natural family, including the genera Cidaris, Biadema, 
and Astropyya, which he constituted and characterised thus : — 

1 Peteks, ' Ueber Gruppe der Diademen,' p. 2, 101. Konigl. Akademie der Wissenchaften Augt., 
1853, BerUn. 

- ' Annals of Philosophy,' new series, vol. s, p. 426, 1825. "An attempt to divide the Echinidae or 
Sea-Eggs into natural families." 



DIADEMAD^.. 81 



1. Famili/ — Cidarid^. Cidurites, Lamarck. 

Body with spines of two sizes; larger ones either club-shaped or very long; spine- 
bearing tnbercles perforated at the summit. 



Genus 1 — Cidaris, Klein, Lamarck. (Les Turbans.) 

Body depressed, spheroidal ; ambulacra waved ; small spines compressed, two-edged, 
two-rowed, covering the ambulacra, and surrounding the base of the larger spines. 

This genus may be divided according to the form of the larger spines : the extra- 
ambulacral beads have only two rows of spines. 

Cidaris impekialis, Lamh. Klein., Nat. dispositio Echinodermatum, tab. vii, fig. a. 



Genus 2 — Diadema, Gray. (Les Diademes.) 
Body orbicular, rather depressed ; ambulacra straight ; spines often fistulous. 

EcHiNOMETKA SETOSA, Rumph. Leske, Klein., Nat. disp. Ecbinid., tab. .xxxvii, fig. 1, 2. 
Echinus diadema, Linn. Syst. Nat., by Turton, vol. iv, p. 139. 
— CALAMAEIA, Pallas. Spicil. ZooL, tab. ii, fig. 4 — 8. 



Genus 3 — AsTRorvGA, Grai/. 

Body orbicular, very much depressed ; ambulacra straight ; ovarial scales very long, 
lanceolate ; beads with several series of spines. 

Cidaris uadiata, Leske, apud Klein, tab. xliv, fig. 1. 

The veiy meager characteristics by which Dr. Gray has defined the last two genera 
merely shows that a difference exists, and his description is insufficient for a correct dia- 
gnosis of either ; hence the various opinions extant regarding the character and limits of his 
genus Diadema; only one of the species enumerated as types, Diadema setosa, Rumph., 

11 



83 



CLASSIFICATION OF THE 



is admitted to be a true Diadema. The valuable memoir of Herr W. Peters^ has 
removed some of the difficulties that surrounded this subject, and his grouping of the 
living Diademas makes an important step towards a natural classification of one section of 
this Family. Although the present state of our scientific knowledge of the Diadeniadts 
may be considered as transitional rather than positive, still we possess enough to justify 
the separation of fossil Diademas from existing genera, as proposed by M. Desor." 

The DiADEMADiE, in fact, appear to consist of two types ; one of these, with a few rare 
exceptions, appertains to the present epoch, the other existed diu'ing the deposition of the 
Secondary and Tertiary rocks. The living forms arc in general large, depressed Urchins, with 
thin shells, having the tubercles and pores variously arranged in the different genera. They 
have, in general, very long, slender, tubular spines, and the surface of the stem is covered 
with oblique annulations of small imbricated scales. The fossil species, on the contrary, 
are smaller Urchins, with a thicker test ; having the tubercles and pores variously disposed 
in different genera; the spines rarely attain the length of the diameter of the test; 
they are in general solid, cylindrical, sometimes flattened or awl-shaped, and their surface 
is covered with fine longitudinal lines. I propose to include the following genera in this 
natural family. 



A Table shoimng the Classification of the Diademada. 

Section a. 
/ Spines very long, slender, tubular, 



DIADEMAD^ / 



\ 



covered with oblique annulations 
of imbricated scales. Living in 
tropical seas. 
A few annulated tubular .spines are 
found iu the Upper Chalk and in 
the Coralline Crag. 

Section b. 

Spines short, slender, solid ; surface \ 
covered with fine longitudinal 
lines. 

E.xtinct ; found in the Oolitic, Cre- 
taceous, and Tertiary Rocks. 



DiAUEMA, Gray. 
Savignya, Desor. 
AsTROPYGA, Gray. 
EcHiNOTiiEix, Peters. 



PSEDDODIADEMA, Desor. 

CyPHOSOMA, Agassi:. 
Hemipedina, Wriyht. 

Pedina, Ayassiz. 
EciiiKOPsis, Ayassiz. 



My learned friend M. Cotteau,'' in his classical work on the Echinidae of France, has 
lately proposed an extended classification of the family Diademad^, a resume oi which I 

1 ' Ueber die Gruppe der Diademen, Konigl. Akademie der Wissenschaften,' Berlin Aug., 1853. 

- ' Synopsis des Echinides Fossiles.' 

^ ' Paleontologie Eranoaise, Terrain Cre'tac^,' tom. vii, p. 3"1. 



DIADEMAD^. S3 

herewith subjoin; the genera referred to this family arc divided into four groups, 
based upon the structure of the tubercles, whether they are perforated or not perforated, 
and crenulated or not crenulated. 

In the CiDARiDiE these characters have not much significance, and are present or 
absent in many species of congeneric forms ; in the Diademadjs, however, they arc more 
stable and persistent, and have served to form a great number of genera. If from an 
organic point of view this structure of the tubercles is only of secondary importance, in a 
palscontological sense it affords a character which is readily seen, and nearly always 
Avell preserved. 

The first group comprehends the DiADEjiAOiE^ with tubercles perforated and crenu- 
lated : Hemicidaris, Agassiz ; Acrocidaris, Agassiz ; Pseudodiadeina, Desor ; Biadema, 
Gray ; Hibertta, Michelin ; Microdiadcma, Cotteau ; Heterodiadema, Cotteau ; Asfero- 
cidaris, Cotteau ; Gl^phoct/phiis, Haime. 

The second group includes the genera with tubercles perforated and not crenulated : 
Cidaropsis, Cotteau ; Diademopsis, Desor ; Ilemipedina, Wright ; Ecliinopsis, Agassiz ; 
Orthopsis, Cotteau : Pedinojjsis, Cotteau. 

The third group is destined to receive thegenera which have the tubercles imperforated 
and crenulated : Ci^j^hosoma, Agassiz ; Mkropsis, Cotteau ; Temnopleurus, Agassiz ; Eclii- 
nocijphns, Cotteau. 

The fourth and last group contains the genera with tubercles imperforated and uncre- 
nulated : Goniopygu3,h.^2&^\z; Acropelils, k^^?&VL; Zeiosoma, Cotieaii; Uc/iinocidans,Des- 
moulins ; Codopleunis, Agassiz ; Kmraiaphorus, Michelin ; Codiopsis, Agassiz ; Cottaldia, 
Desor ; Magnosia, IVIichelin ; Gli/jjficus, Agassiz ; TemnecJdnus, Forbes ; Opechinus, Desor. 

The genera which compose these four groups are distinguished by straight or flexuous 
ambulacra, the disposition of the tubercles, the structure of the apical disc, the sutural 
and angidar impressions which mark the ambulacral and inter-ambulacral plates, the 
comparative width of the peristome, and the form and structure of the spines. 

The following table contains a definition of the opposable characters of the thirty -one 
genera composing the family DiADEMADyE. 

^ In my classification of the Eciiiniu/E I have separated Hemicidaris and Acrocidaris as a distinct 

family, the Hemicidakid/E. 



84 



CLASSIFICATION OF THE 



A. Tubercles crenulated and perforated. 

a. Ambulacral areas subflexuou?, provided witb large tubercles at the 

ambitus aud inferior surface .... 

b. Ambulacra straight, provided witb tubercles in all their extent. 

X. Ambulacral and inter-ambulacral plates -without angular impressions. 
X. Inter-ambulacral areas subgranular as they approach the summit. 
y. Apical disc subpentagonal, peristome large. 
r. Each of the ovarial plates of the apical disc carry a large tubercle 
zz. Apical disc, without a large tubercle on its ovarial plates. 

1 . Poriferous plates unequal and irregular. 

If. Spines solid, aciculated, striated 
ifiip. Spines tubular, verticillated 

2. Poriferous plates straight, equal, regular 

)jy. Apical disc narrow, annular, peristome reentrant 

yyy- Apical disc elongated, prolonged into the middle of the single inter- 
ambulacral area ; peristome narrow 

xx. Inter-ambulacra smooth near the summit, and presenting a stellate 
appearance ..... 

XX. Ambulacral aud inter-ambulacral plates marked with angular impressions 



Hemicidauis. 



.\CROCIDAKIS. 



PSEUDODIADEMA. 
DiADEMA. 

HiBERTIA. 

MiCRODIADF.MA. 

IIeterodiadema. 

asteeiocibaeis. 
Glypiiocyphus. 



15. Tubercles perforated and not crenulated. 

(I. Ambulacra subflexuous, provided with tubercles only towards the 

ambitus and inferior surface .... Cidakopsis. 

//. Ambulacra straight, provided with tubercles in all their extent. 

X. Pores simple near to the summit. 

X. Ambulacral plates unequal, irregular. 

//. Apical disc largely developed, peristome wide. 

:. Miliary zone extended; principal inter-ambulacral tubercles very large, 

placed on the external border of the plates . . . Diadl.moi'SIS. 

t.-. Miliary zone narrower, tubercles tolerably large and placed in the middle 

of the plates. ..... Hemipedina. 

yy. Apical disc narrow, peristome slightly developed, tubercles very small . Echi.nopsis. 
XX. Ambulacral plates, straight, regular, sutures very apparent . . Orthopsis. 



.\x. Pores in double series at the superior surface and towards the ambitus 



Pedinopsis. 



DIADEMAD.E. 85 

0. Tubercles not perforated and crenulated. 

a. Ambulacral and inter-arabulacral plates without angular impressions. 

X. Form depressed, tubercles rather large, peristome widely open . . Cypiiosoma. 

-xx. Form inflated, tubercles small, peristome narrow . • • Miceopsis. 

h. Ambulacral and inter-ambulacral plates marked with angular, and 
sutural impressions. 

X. Apical disc sub-circular, inter-ambulacral tubercles forming many rows 

towards the ambitus ..... Temnopleurus. 

XX. Apical disc pentagonal, inter-ambulacral tubercles forming two rows . Echinocyphus. 

D. Tubercles not perforated and not crenulated. 

a. Ambulacral and inter-arabulacral plates without angular and sutural 
impressions. 

X. Apical disc smooth, ovarial and ocular plates perforated below at their ex- 
ternal angle ..•■•• Goniopygus. 

XX. Apical disc furnished with a large tubercle on each ovarial plate ; ovarial 

and ocular plates perforated at some distance from the border . Acropeltis. 

XXX. Apical disc granular, deprived of tubercles ; ovarial and ocular plates per- 
forated at some distance from the border. 

X. Tubercles rather large, forming regular vertical rows. 

y. Two rows only of inter-ambulacral tubercles ; mammelon large and pro- 
minent ...... Leiosojia. 



II'J- 



More than two rows of inter-ambulacral tubercles ; mammelon small . Eciiixocijjauis. 



yyy. Inter-ambulacral tubercles not extending above the ambitus ; inter- 
ambulacral area forming, at the upper part, a depressed zone, 
perfectly circumscribed. 

C-. Four rows of inter-ambulacral tubercles towards the ambitus . C(ELOpleuuus. 

". Two rows of inter-ambulacral tubercles towards the ambitus ; spines 

long, sub-tricarinated, and slightly bent . . . K.euaiapiiokus. 

yyyj- Ambulacral and inter-ambulacral tubercles limited to the inferior sur- 
face, replaced above the ambitus by caducous granules . . Codiopsis. 

XX. Tubercles small, forming very regular horizontal rows. 

y. Peristome small, pores simple towards the ambitus . . Cottaldh. 

>j>j. Peristome very wide, sub-pentagonal, pores forming double rows from 

the ambitus to the moulh .... Macnosia. 



86 PSEUDODIADEMA 

D. Tubercles not perforated and not crenalated — continued. 

yyy. Inter-ambulacral tubercles irregularly arranged above the ambitus, often 

lacerated ...... Glypticcs. 

h. Arnbiilacral and inter-ambulacral plates provided with angular and sutural 
impressions. 

,x. Impressions angular ..... Temkecuixl'S. 

XX. Impressions sutural, and angular, and much more defined . . Opecuis'US. 

The stratigraphical (li.-;tribution of the Diadeniadse extends from the Trias to the 
modern epoch, where a few species now live in tropical seas. Of the thirty-one genera 
enumerated in the above table, seven are proper to the Oolitic period : Microdiadema, 
Aakrocidarlx, Cidaropsis, Heiuipedlna, AcropeUin, GlypticMS. Seven to the Cretaceoas 
period : Ileterodiadema, GlyphocyphuH, Orlhopsiis, Pedinopsix, Echinoci/phm, Leisoma, 
Codiojjsis. Five are special to the Tertiary period : Jlibertia, Echinojms, Cceloplevrm, 
TemnecJdnm, OpecJdnus. Three to the jNIodern period : Diadema, Echinocidaris, and 
Karaiaphorus. One genus, Pneudodiadema, is common to the Oolitic, Cretaceous, and 
Tertiary periods. Three genera are found in the Oolitic and Cretaceous periods ; Ilemi- 
c2V«r/y, which commenced in the Trias, ^croczV/ar/s and J/«(7«o*?ff, but neither extend above 
the Neocomian. Four genera are common to the Cretaceous and Tertiary periods : 
Goniopyyus, Collaldiu, Cyphosoma, and Micropms. The genus Temnopleurm appeared 
in the Tertiary period and exists in our present seas. 



PsEUDODiADEMA, Desor. 1854. 

This genus is composed of small Urchins with a moderately thick test, which rarely 
attiiins two inches in diameter ; the ambulacral areas in general arc one third or even one 
half the width of the inter-ambulacral areas ; the primary tubercles of both areas are 
perforated, and nearly all of the same size ; the bosses are small, and have sharply crenu- 
lated summits. 

The ambulacral areas have two rows of tubercles; the inter-ambulacral areas two 
rows only, or two rows of primary and two or four short rows of smaller secondary 
tubercles, or they have four, or six rows of nearly equal-sized primary tubercles at the 
ambitus. 

Tlie ])oriferous zones in general are narrow and straight ; the pores in one section are 
unigcniinal throughout, and in another they are bigeminal in the upper part of the zones. 
The apical disc is small ; and the anterior ovarial plates are larger than the posterior pair. 

The motith-opening is large, the [)eristoine deeply notched, and the oral lobes are 
nearly equal. 



FROM THE LOWER GREEXSAND. 87 

The spines rarely attain the length of the diameter of the test ; in general they are 
much shorter, cylindrical, or needle-shaped, and have a prominent, milled ring near 
the articulating head ; the rim of the acetabulum is crenulated, and the socket perforated ; 
the surface of the stem is sculptured with delicate longitudinal lines. 

The Paeudodiademata are all extinct, and found in the Liassic, Oolitic, Cretaceous and 
Tertiary rocks. 

Pfseudodiadema differs from Diadema in having solid spines, with a smooth surface, 
the sculpture, in most cases, consisting of microscopic, longitudinal lines; whilst in 
Diadeitia the spines are tubular, and have oblique annulations of scaly fringes on their 
surface. Pseudodiadema differs from Cyphosoma, a Cretaceous genus, in having the 
tubercles always perforated, those of Cyphoxoma being imperforate. It differs from 
Hemipedina in having a small apical disc, and tubercles with crenulated bosses, those of 
Hemijjpdtna being smooth ; and from Pedina in having the pores unigeminal or 
bigeminal, those of Pedina being arranged in triple, oblique pairs. 

Pseudodiadema may be divided into two sections, from the different manner the 
pores are arranged in the zones. In one group the pairs of pores form a single 
file throughout; in another the pores are more numerous, and crowded together in 
the upper part of the zones. Professor M'Coy has proposed the genus Biplopodia for 
the latter. It may be objected, however, that the crowding together of a greater number 
of pores in a zone is, at most, a sectional and not a generic character, inasmuch as the 
arrangement is subject to great variation in the diplopodous species themselves, and is, 
moreover, often only an adult development. 



A. — Species front the Lower Greemand. 
PsErD0Di.\DE3iA EOTCLABE, Ago^fsiz. PI. XIV, figs. 3 a, b, c. 

DiADEMA EOTCLAKE, Ag(u«iz. M^m. des Sc. nat. de Xeuchatel, vol. l,p. 139, tab. xiv, 

fig?. 10—12, 183C. 

— — Bet Moulin*, £tiideg 8ar les ficliinidei", p. 316, No. 2.^, 1837. 

— OBXATCM, Jga»n:. Catal. SyBt. Ectyp. fogs. Masei Neoc, p. 8, 1840. 

— EOTCLAKE, JffOMiz. Dcfcript. des lochia, fois. de la Saitse, part 2, p. 4, 

Ub.xvi, fig. 1—5, 1840. 

— MACKOSTOMA, Ayatnz. Ibid., p. 10, tab. xvi, fig. 22 — 26, 1840. 

— KOTCLABE, Ag(u*iz et Detor. Catal. Itaison. des Echinides, Ann. dc« Sc. nat, 

.3e serie, t. vi, p. .346, 1846. 

— MACKOSTOMA, Jgassiz et Beior. Ibid., p. 347, 1846. 

— — Bronn. Index Palieontologicus, p. 418, 1846. 

— COKOXA, Grot. OursinB fosa. de rietre, p. 33, pi. i, fig. 21— 2.3, 1848. 

— EOTCL.vKE, Marcou. Recherch. geol. ear le Jura Salinois, M6m. Soc. Geo), de 

France, Ire fserie, t. iii, p. 14.3, 1848. 



88 



PSEl'DODIADEMA 



DiADEMA llOTULAliE, 

— MACltOSTOMA, 

— KOTULAEE, 

DiAPEMA DUBIUM, 



EOTULAUE, 



PsEUD0UIADE5IA 



B'Orhiyny. Prod. dePak'unt. Strat., t. ii, p. 89 ; Et. 17, No. 489, 

1850. 
D'Orbigny. Ibid., No. 491, 18.".0. 
Cotteau. Cat. £cli. Neocom., Bull. Soc. de I'Yonne, t. v, p. 285, 

1851. 
Sharpe. Sands and Gravels of Farringdon, Quart. Journ. Geol. 

See, vol. X, p. 194, 1853. 
Foi-bes. In Morris's Catalogue of British Fossils, 2nd ed., p. 76, 

1854. 
Cotteau. Paleontologie Francaise, Ter. Cretact, vol. vii, p. 422, 

pi. 1097, figs. 11 — 13; pi. 1098 and 1099. 
Besor. Synopsis des Echinides fossiles, p. 69, 1856. 



— MACltOSTOMA, Besor. Ibid., p. 68. 

— KOTLLAiiE, Cotteau. Etudes sur les Echinides de I'Yonne, t. ii, p. 24, pi. xli.x, 

figs. 1—5, 1857. 

— piETETi, Cotteau. Ibid., p. 31, pi. I, figs. 7 — 10, 1857. 

— TUisERiALE, Besof. Synop. des Ecliin. foss., p. 445 (Suppl.). 1858. 

— ROTULARE, Bujardiii et Hufc. Hist. Nat. des Zoophytes, Echinoderm., p. 

428, 1862. 

— PERIQUETI, Biijardiii et Hupc. Ibid. 

— MACUOSTO.MA, Bujardin et Hupt. Ibid. 

— TRISERIALE, Bujardiii et Ilupi-. Ibid. 



Test small, circular, slightly pentagonal, moderately convex above, and flat below ; 
poriferous zones narrow, straight ; pores in single file ; anibulacral areas large, two 
rows of close-set marginal tubercles ; inter-ambulacral areas, four rows of tubercles at 
the ambitus, the outer rows disappearing on the upper surface ; miliary zone wide, 
depressed near the disc, and covered with an abundance of well-formed granules. Mouth- 
opening large, decagonal ; peristome deeply notched ; lobes unequal. 

Dimensions. — Height four tenths of an inch; transverse diameter, one inch. 

Description. — This is a very rare Urchin from the remarkable deposit of fossiliferous 
sands and gravels near Farringdon in Berkshire, about the age of which so many different 
opinions have been given ; perhaps the Echinidaj found therein may assist to determine the 
problem whether these beds belong to the Lower Greensand, or to a " more modern member 
of the Cretaceous Series than the Chalk," as maintained by the late Mr. Daniel Sharpe, 
F.G.S.^ The Diadema now before us is a well-known and characteristic species, of the 
middle stage of the Neocomian formation, cQwiwmn^ Echinospatagus cordiformis ; and the 
extensive table of synonyms prefixed to this article shows how widely it is distributed in 
beds of the same age on the continent of Europe. 

The test is of medium size, circular or slightly pentagonal, moderately convex on the 
upper surface, and nearly fiat beneath. 

1 " On the Age of the Fossiliferous Sands and Gravels of Farringdon and its Neighbourhood," ' Quart. 
Journ. of the Geological Society,' vol. x, p. 176. 1853. 



FROM THE LO^^'ER GREENSAND 89 

The ambulacra! areas are wide (fig. 3 a, b) and have two rows of tubercles placed on 
the margin of the area ; these are small, uniform in structure, set closely together, and 
gradually diminish from the equator to both poles ; a band of granulations down the 
middle of the area divides the two series from each other : the poriferous zones are narrow 
and straight (fig. 3 b) ; the pores are round and simple, and arranged in a single file 
throughout the zones (fig. 3 c). 

The inter-am]julacral areas are occupied at the ambitus by four rows of tubercles ; the 
inner rows extend from the mouth to the disc, and the outer rows diminish in size on 
the upper surface and disappear before reaching the disc ; the tubercles forming the inner 
row are about the size of those in the ambulacra ; those of the outer row are sensibly 
smaller (fig. 3 b). The miliary zone is large, and slightly depressed near the summit ; it 
is filled with numerous granules of unequal sizes, some of which are mammUlated and 
perforated ; the granules are disposed in circles around the areolae, and fill the entire area 
of the zones with a beautiful oniamentation ; the examples from Farringdon have lost 
much of this character from the process of fossUization in those gravel beds. 

The base of the test is flat, and presents a highly tubercular surface (fig. 3 a), the foiu* 
rows of tubercles in the inter-ambulacral areas being all distinctly developed in this 
region. The mouth-opening, one half the diameter of the test, is proportionally large : 
the peristome is deeply notched into the lobes, the ambulacral portions being one half larger 
than those of the inter-ambulacral arches. In fig. 3 c, I have given a section of the 
base, magnified four diameters, showing the relation of all these parts to each other. 

Affinities and Differences. — ^This Urchin presents many varieties of form, which have 
been described by difierent authors as so many distinct species, an error that has been 
now corrected, as shown in the table of synonyms. It resembles P. Bourgneti, Ag., 
found with it in the same Xeocomian beds, but is distinguished from that species 
in having the primary tubercles less developed, more closely set together, and more 
homogeneous ; and in the secondary or outer series of tubercles being larger and more 
reffularlv arranged ; thev are, however, nearlv allied forms of one tvpe of structure. 

Localifi/ and Strafi^raphical Poniion. — This Trchin in England has hitherto been 
found onlv in the sands and gravels near Farringdon, where it is extremely rare. It was 
collected from these beds by the late Mr. D. Sharpe, and I obtained one specimen in the 
same locality. On the continent of Europe it is one of the most characteristic fossils of the 
"Terrain Xeocomien," and is found principally in the middle beds of that formation. 
'hi. Cotteau records the following localities in France where it has been collected : — Billecul, 
Mieges, et I'ermitage de Censeau, Nozeroy (Jura) ; Morteau, Hautepierre (Doubs) ; Ger- 
migney (Haute-Saone) ; Vassy, Bettancourt, (Haute-Marne'i ; Thiefi'rain, Vandoeu\Te, 
Marolles (Aube) ; Cheney, Flogny, Moneteau, Auxerre, Gy-rEveque, Leugny, Fontenoy, 
Saints, Pereuse (Yonne) ; in all these locahties it is collected in abundance from the 
Ikliddle Xeocomian ; and at Le Rimet (Isere), Villefargeau, Perrigny (Yonne), it is very 
rare in the Upper Neocomian. In Switzerland it is found near Locle in the Lower 

12 



90 PSEUDODIADEMA 

Neocomian ; and at Laiuleron, Saiiite-Croix, Ilauterive in the Middle Neocomian, so that 
it forms a leading fossil of the Neocomian formations. 

History. — This Urchin was at first referred by Professor Forbes to the Diadema dubium 
of Albin Gras, but a careful comparison of specimens proved this to be an error. It 
appeared under that name in Mr. Sharpe's list of Echinodermata from the sands and 
gravels of Farringdon, and in the second edition of the ' Catalogue of British Fossils.' 



PsEUDODiADEMA FiTTONi, Wright. PI. XV, Figs. 1, a — g. 

Diadema Autissiodokense, Wright. Ann. and Mag. of Nat. History, New Series, 

vol. X, p. !)1, 1852. 

Test pentagonal, depressed ; inter-ambulacral areas with two rows of primary tubercles 
and two incomplete series of small secondary tubercles, which disappear on the upper 
surface ; ambulacral areas prominent, with two rows of primary tubercles much diminished 
in size at the upper surface; poriferous zones narrow, subflexuous. Pores bigeminal 
near the ovarial disc, and at the circumference of the mouth. 

Dimensions. — Height four tenths of an inch ; transverse diameter nineteen twentieths 
of an inch. 

Description. — In its general outline this beautiful Urchin resembles P. depressum of 
the Inferior Oolite ; in the details of structure, however, it is very distinct from that form. 
The circumference is pentagonal, from the convexity of the ambulacral areas, and the upper 
and under surfaces are much depressed (PI. XV, fig. 1 a, b, c, d). 

The inter-ambulacral areas are one third broader than the ambulacral ; two rows of 
primary tubercles occupy the centre of the plates ; there are about ten pairs of tubercles 
in each area, which are of a moderate magnitude, and gradually diminish in size from 
the ambitus to the base and summit ; the mammillary eminences are small, their summits 
sharply crenulated, and the tubercles, of proportional size, are deeply perforated (fig. 1 (/) ; 
at the ambitus six rows of granules separate the tubercles from each other (fig. 1 e) ; 
towards the upper part of the mihary zone the four central rows are absent, leaving a naked 
space in the middle of the area ; three rows of granules in like manner separate the tubercles 
from the poriferous zones ; at the base of the area, and extending as far as the ambitus, 
there are incomplete rows of small secondary tubercles ; these gradually diminish in size, 
and disappear at the upper surface, which is occupied with an unequal close-set granulation 
about three rows deep (fig. 1 b) ; the ambulacral areas, one third narrower than 
the inter-ambulacral, are very prominent and convex, and occupied by two rows of 
primary tubercles about ten in a row ; the lower six pairs of tubercles are nearly 
as large as the corresponding tubercles in the inter-ambulacral areas, but the upper 



FROM THE LOWER GREENSAND. 91 

four pairs are much smaller, so that, whilst thei-e is a great uniformity in the size and 
form of the tubercles at the base and ambitus of the test, there is a very marked 
difference between those of the ambulacra and inter-ambulacra in the vicinity of the apical 
disc (fig. 1 b) ; the inter-tubercular space is occupied by a zigzag band of granulation, which 
is narrow below where the tubercles are large, and broader above where they are small 
(fig. 1 e). The poriferous zones are narrow and subflexuous; and the pores arranged 
in single pairs ; near the disc they are slightly bigeminal ; the apical disc is absent in our 
specimen. The mouth-opening is large and the peristome slightly decagonal (fig. 1 c). 

Ajfinities and Differences. — Psciidodiadema Fitloni nearly resembles P. Bour(/ueti, Ag., 
but diflers from it in the rudimentary condition of the upper tubercles of the ambulacra, 
and in having the intermediate granulation on the miliary zone less homogeneous. 

Locality and Slrafiffraphlcal Position. — I collected this Urchin from the Lower Green- 
sand at AtherficJd, in bed No. 4 of the Cracker group. Dr. Fitton's section ; it must be very 
rare, as none of the cabinets of Atherfiekl fossils hitherto examined by me contain a 
specimen. 

History. — I discovered this fossil in IS 50, and in the first instance erroneously 
identified it with a specimen found in France, and then briefly described by M. Cotteau 
as Diadema Autissiodorense. The fine figures and detailed description lately published 
by M. Cotteau in his additions to the " Paleontologie Francaise " have enabled me to 
correct my error, and I now dedicate this species to the memory of my late friend 
Dr. Fitton, F.R.S., whose admirable memoir on the Atherfiekl section and the strata below 
the Chalk will long remain models of patient research and accurate scientific investigation. 



PsEUDODiADEMA Malbosi, Agassiz 8^' Desor. PI. XX, figs. 1, a—f. 

Diadema Malbosi, Agassi: and Besor. Catal. r.iis. des Eehinides, Ann. Science. 

Nat., 3me ser., t. vi, p. 350, 184C. 

— — B'Orhignij. Prodrome de Paleont. strat., t. ii, p. 201, 

1850. 
DiPLOPOBiA — Desor. Synops. des Eehinides fossiles, p. 7S, pi. xii, figs. 

12—14, 1856. 
— — Leymerie et Cotteau. Cafnl. tics Ecbinid. Foss. des 

Pyrenees, Bullet. Soc. Geol. dc France, 2" ser., t. xiii, 

p. 324, 1850. 
DiAUEMA Mackesoxi, Forbes. Woodward's Notes on British fossil Diadems, 

IMem. Geol. Surv., Decade V, 185G. 

— Mackiei, TJ'oodward. Ibid. 

— Malbosi, Pictet. Traite de Paleont., 2" ed., t. iv, p. 245, 1857. 
DirLOPODiA — I>'.//-c//«;c Ics Corbicrcs. Mem. Soc. Geol. de France, 2" ser., 

t. vi, p. ;!84, 185!). 



02 PSEIDODIADEMA' 

DiPLOPoniA ilAi.BOSi, Bnjardin et Hiipe. Hist. Nat. des Zooph. Ecbiuo- 

dermes, p. 501, 18G2. 
PsEUDODivDEMA ]\[.vLBosi, Cotteou. Ecliinid. Foss. des Pyrenees, p. 2G, 1863. 

— — Cotteau. Paleontologie Fran^aise, Ter. Crctace, torn, vii, 

p. 448, pis. 1106 et 1107, 186."). 

Test large, subcircular, upper surface convex, slightly inflated, base rounded and 
flattened, ambiilacral areas narrow, contracted at the upper part by the width of the pori- 
ferous zones, two rows of tubercles twenty to twenty-two in each row. Inter-ambulacral 
areas wide with four, six, or eight rows of tubercles at the equator, the two inner rows 
having eighteen to twenty tubercles in each, extend from the peristome to the disc, all 
the others disappear at different points on the sides. Small secondary tubercles 
scattered irregularly among the primary series in the inferior part of the areas. Poriferous 
zones narrow at the base and sides ; pores in double file from the ambitus to the disc, 
where they increase in width, and on the upper third are largely bigeminal. Mouth - 
opening moderate in size ; peristome nearly equal lobed ; discal opening large and 
acutely pentagonal. 

Dimensions. — Transverse diameter two inches ; height thirteen twentieths of an 
inch. 

Description. — ^This is a very rare British Urchin, and as nearly all the tests have 
been either broken, crushed, or otherwise distorted, it is difficult to form a correct 
idea of its form. I have carefully examined the original specimens collected by 
Mr. Mackeson, F.G.S., from the Lower Greensand at Hythe, and presented by him to 
the Royal School of Mines ; these I have compared with a series collected by my 
friend the Rev. T. Wiltshire, from the Lower Greensand at Whales' Chine, Isle 
of Wight, with which they agree, and both correspond with the figures and descrip- 
tion of Pseudodiadema Malbosi given by M. Cotteau in the ' Paleontologie Franjaise,' 
and with a good type specimen kindly presented to me by ]\L Bayle, of the Ecole 
des ]\Iines, Paris. I have no hesitation, therefore, in considering D. Mackcsoni, Forb., 
identical with D. Malbosi, Agass. It is important likewise to note that both belong to the 
same geological horizon ; the French specimens were collected from the Upper Neoco- 
mian, associated with EclMiospatagus Collegnii, Sisni., and the British specimens from 
the Lower Greensand at Ilythe, and the Crioceras-beds, Lower Greensand, at Whales 
Chine, Isle of Wight, the English equivalent of the Continental Neocomian formation. 

This Urchin attains a considerable size ; Mr. Wiltshire's cabinet contains a specimen 
measuring two and a half inches diameter. The base of this fossil is nearly circular, and 
only slightly pentagonal. In some of the Hythe specimens in the Museum of the Royal 
School of Mines, the upper surface is convex and moderately inflated, and the ba<e 
rounded and flattened. 

The anibulacral areas are narrow and contracted at their apices by the width of the 
poriferous zones above Mig. \,(j)\ they are slightly inflated, and furnished with two 



FROM THE LOWER GREENS AND. 93 

rows of large tubercles, from twenty to twenty-five in each, according to the size of the 
Urchin, all deeply crenulated and perforated, and gradually diminishing from the equator 
to the apertures ; a single sinuous line of granules separates the tubercles, which are 
placed closely together in the area (fig. 1 d). 

The poriferous zones are narrow at the base and sides, where the pores are arranged in 
a single file (fig. 1 e); at the upper part they are bigeminal (fig. 1 cf), the double rows 
encroaching on the width of the anibulacral area and diminishing the size of the tuber- 

cles therein. 

The poriferous plates are prolonged to the base of the tubercles in more or less apparent 

irregular sutures (fig. 1 d)- 

The inter-ambulacral areas are widely developed, the large plates support tubercles 
closely resembling those of the ambulacra (fig. 1 y). In the figured specimen there are 
six rows at the equator, and in larger specimens there are eight distinct rows. The 
two internal rows have eighteen tul)ercles a little larger than the others, extending 
from the peristome to the disc ; the other rows have a more limited range, and disappear 
on the upper surface. It is only in the largest specimens that eight rows are found at the 
ambitus, the tubercles of the shorter rows being a little less than those of the two internal 
series (fig. 1 y) ; besides the primary tubercles a number of small secondary tubercles 
are crowded along each side of the median suture, between the peristome and the 
ambitus, and others occupy spaces by the side of the poriferous zones. The miliary zone 
is wide, smooth, and depressed at the upper surface ; the granules are irregularly scattered 
on its lower half, and some of them are even developed into small mammillated tubercles 
on the npper surface; they form hexagonal circlets around the areas of the primary 
tubercles ; the median suture is very well defined, and lies in a smooth depression of the 

test (fig. 1 n, c). 

The mouth-opening (fig. 1 d) is large and pentagonal, and the peristome divided into 
lobes of unequal sizes; the arches that span the ambulacra are longer than those of the 

inter-ambulacra. 

The apical disc was very large ; the opening is pentagonal and acutely angular, the 
angles extending far into the median suture of the inter-ambulacra (fig. 1 a andy). 

°The spines" are slender, and circular; above the milled ring of the head, there 
is a short portion of the stem ornamented with fine longitudinal lines (fig. /), 
whilst the portion beyond is entirely smooth. I have represented this character in the 

fragment fig. 1 /• 

M. Cotteau has figured a large example of this species from the Upper Ncocomian ; 
from this we learn that age produces important modifications in the structure of the test ; 
the poriferous zones arc very wide, and bigeminal, not only on the upper surface, but as 
far down as the ambitus ; besides the eight rows of primary tubercles there are some 
rudiments of secondary tubercles ; the miliary zone is wide and depressed at the upper 
surface; the discal opening becomes more angular, and the ovarial plates penetrate 



94 PSEUDODIADEMA 

further into the ambiilacral areas ; the mouth-opening is circular, and the peristome nearly 
equally lobed. 

J/finities and Differences. — Pseudodiademu ]\Ialbosi resembles some of the larger forms 
of P. Bronyniarii, from the Grey Chalk of Folkestone, in the cabinet of my friend the 
Rev. T. Wiltshire, and figured in PI. XX, fig. 2 a, h, in PL XXI b, fig. 3, and 
PL XXI A, fig. 2. The tubercles in P. Bronrjniarti are not so numerous in each row; 
the poriferous zones are narrower, and the bigeminal arrangement of the pores, so well 
developed in P. Malbosi, is less distinct in P. Brongniarli. These certainly are nearly 
aUied species, and require a careful examination to detect the small differences existing 
between them. 

p. Malbosi resembles P. dubium, Gras, from the same horizon. I have only a mould 
in plaster of the latter, not sufficiently sharp for scientific accuracy. 

Localitij and Stratigraphical Position. — 'Lhe specimens I have figured were collected 
from the Lower Greensand at Whales Chine, Isle of Wight, in the Crioceras-beds that 
pass across that chasm, associated with Ammonites Martini, D'Orb., Crioceras Boioer- 
bankii. Sow., Gryplicea sinnata. Sow., &c. 

The specimens in the Museum of the Royal School of Mines were collected by Mr. 
H. B. Mackeson, from the Lower Greensand (Kentish Rag) of Llythe, and presented by 
him to that institution. Specimens are extremely rare in both the places cjuoted. 

The foreign /ocf//zY/r'.s, according to jM. Cotteau, are La Classe (Aude), Opoul (Pyrenees 
Orientales), where it is abundant in the Upper Ncocomian beds, associated with Echino- 
spatagws CoUegnii, D'Orlj. 



B. — Species from the Gault. 
PsEUDor)iADEM.\ WiLTSHiREi, Wright, nov. sp. PL XVI, figs. 1 c— /, 2, 3. 

Test moderately large and equally depressed at both poles ; ambulacral areas wide, 
with two rows of tubercles, large and approximated in the lower half of the area, small and 
detached in the upper ; poriferous zones narrow, flexuous, pores in single file throughout ; 
inter-ambulacral areas narrow, two roAvs of primary tubercles, and a few irregular 
secondary tubercles at the base of the area, primaries large and approximated in the 
lower half, small and remote above; miliary zone wide and finely granulated above, 
narrow and with large granules below ; spines long and slender, the stem ornamented 
with delicate longitudinal lines. 

Dimensions. — Height six tenths of an inch ; transverse diameter an inch and a half. 

Description. — We only possess a fragment of this beautifid form, still it has been 
enough to enable Mr. Bone to give a restoration of the test in PL XVI, fig. 1 b. The body 
is inflated at the sides, and nearly equally flattened on the upper and lower surface. The 



FROM THE GAULT. 95 

ambulacral areas are wide and have two rows of tubercles ; those on the lower portion of 
the area are large and closely set together, and those on the upper part are dispropor- 
tionately small and placed widely apart (fig. 1 b) ; some very fine granules divide the large 
basal tubercles, and a numerous granulation surrounds the smaller tubercles on the upper 
part (fig. \ b). 

The inter-ambulacral areas possess only two rows of primary tubercles ; those near the 
base are about the same size as the corresponding tubercles in the ambulacra, on the upper 
part of the area, they are larger, and diminish more gradually in size, so that the 
difference in the tubercles on the upper surface readily distinguishes the ambulacral from 
the inter-ambulacral areas ; an irregular row of four small secondary tubercles occupies 
the outer side of the base between the primaries and the poriferous zones, and a like 
central row extends through the middle of the lower part thereof (fig. 1 c). 

The miliary zone is wide and depressed in the upper part, and the plates are here 
covered with numerous small granules, that cluster chiefly around the bases of the small 
tubercles, the median sutural space being depressed and nude (fig. 1 b) ; the lower part 
of the zone is narrow, and the granules are much larger and more closely set together ; 
many of them are raised on small mammillons, with secondary tubercles interspersed 
among them (fig. 1 c). 

The large primary tubercles of both areas have very large areolas (fig. 1, c), with well 
defined margins. Each areola consists of two parts, an outer circle, consisting of a band 
covered with microscopic granules (fig. 1 d), and a smooth inner portion, from whence the 
boss arises (fig. 1 e). This kind of ornamention is very remarkable ; it is very well pre- 
served in the fragment before me, and correctly represented in figs, d and e. The summit 
of the boss is sharply crenulated, and the tubercle deeply perforated. 

The spines were long and slender, as seen by some imprints on the slab (figs. I, 2, 3); 
the acetabulum of the small head is marked by coarse crenulations, the milled ring is 
prominent, and the whole surface of the stem covered with fine longitudinal lines. 

Affinities and Differences. — This species belongs to the group of which P. Normanim 
(PI. XXI, fig. 3) may be regarded as the type. It differs froni that species, however, in 
having smaller primary tubercles and fewer and smaller secondaries, in having narroAver 
ambulacra and less flexuous poriferous zones. The miliary zone is likewise less distinctly 
marked ; the general contour of the test is different, for the upper and lower surfaces are 
more depressed and the sides less inflated. 

Locality and StratigrapUcal Position. — This unique specimen was found by the Rev. 
T. Wiltshire, F.G.S., in the Gaalt at Folkestone, in a bed near the base of that formation. 
I have very great pleasure in dedicating this species to my kind friend as an acknow- 
ledgment of the important assistance he has rendered me during the progress of this 
work, by the generous contribution of all his best specimens for figuring, his able notes 
on certain species of Cidaris, and other valuable aid frankly given on all occasions when 
required. 



9G 



PSEUDODIADEMA 



c. — Species from the Upper Greensand. 



PsECUODiADEMA RiioDANi, Agassk. PI. XVIII, figs. 3 a — c. 



DiADEMA RhODAKI, 



Luc^, 
Rhodani, 



Rhodani, 

Luce, 

Rhodani, 

LUCE, 



Rhodani, 



PSEUDODIADEMA LuCiE 



DiADEJtA 

— \mcr, 

— Desoki, 

pustulatum, 

Psecdodiadema LuciE, 



Agassi:. Cat. Syst. Ectyp. foss., Mus. Neoc, Supplement, 

1840. 
Agassic. Idem, Mas. Neoc, p. 8. 
Agassi:. Desc. des Echinid. foss. de la Suisse, torn, ii, 

p. 9, pi. xvi, figs. 16—18, 1840. 
Agassi:. Idem, p. 8, pi. xvi, figs. 11 — 15, 1840. 
Agassi: and Desor. Cat. Raison. des Echinld., Ann. des 

Science Nat., 3' sen, t. vi, p. 346, 1846. 
Agassi: and Desor. Idem. 
Bronn. Inde.\ Palseontologicus, p. 418, 1848. 
Bronn. Idem, p. 419. 

Albin Gras. Oursin. foss. de I'lsere, p. 33, 1848. 
IfOrhigmj. Prodrome de Paleontol. strat., t. ii, p. 142, 

Et. 19, 1850. 
Reiieriei: Mem. Geol. sur la Perte du Rhone, p. 49, 

1853. 
Morris. Catalogue of British Fossils, 2nd ed., p. 70, 1854. 
McCoy. Mesozoic Radiata, p. 67, 1854. 
Desor. Synopsis des Echinides fossilcs, p. "1, 1855. 
Rhodani, Desor. Idem, p. 71. 

— Picfef. Traite de Paleontol.. 2'- ed., t. iv, p. 244, 1857. 
Picfef. Idem. 
Forbes. Notes by S. P. Woodward ; Memoirs of the Geol. 

Surv., Decade V, p. 8, 1856. 
Forbes. Idem, p. 8, 1856. 
Dujurdin et Hupe. Hist. Nat. des Zoophytes, Echino- 

dermes, p. 498, 1862. 
Rhodani, Dujardin et Hupi. Idem. 
— Cotteau. Paleontol. Francaise, Terrain Cretace, p. 460, 

pi. 1110, 1864. 



Diapiosk. — Test circular, depressed, slightly convex above, very concave beneath, 
a little inflated at the angles ; ambulacral areas with two complete rows of tubercles, 
fourteen to fifteen in each, and three incomplete rows of small secondary tubercles at the 
base, five or six in each ; inter-ambulacral areas with two rows of primary tubercles, thirteen 
or fom'teen in each, and four rows of small unequal secondary tubercles at the base; 
primary tubercles large at the ambitus, suddenly diminishing in size in both areas on the 



FROM THE UPPER GREENSAND. 97 

upper and under surface ; plates covered with a fine uniform granulation ; moutli-opening 
situated in a concave depression. 

Dimensions. — Transverse diameter one inch and one tenth of an inch, height half an 
inch. 

Description. — Although this Diadema exhibits a group of well-marked specific charac- 
ters, its history, nevertheless, is involved in much confusion, from want of a careful 
examination of the anatomy of the shell. 

The prominent ambital tubercles in the inter-ambulacra, their sudden diminution 
in size on the upper surface, with the baldness of the test in that region, and the crowding 
of the base with small tubercles nearly uniform in size, form a group of persistent 
characters which distinguish Pseiidodiadema Rhodani from all its congeners. 

The smaller forms of this species were figured and described by Professor Agassiz as 
Diadema Lucce, and the large tests as Diadema Bhodani. A series of specimens, of 
different ages, has since shown that these two forms are identical. 

This initial error introduced the confusion that followed, and has rendered it a matter 
of some difficulty to understand the synonyms of this species ; the careful study of a 
good type form sent by the late M. Sgemann from the Gault (Etage Albien, d'Orbigny) 
of Clars, near Escragnolle, department of the Var, has enabled me to compare our English 
examples with an undeniable specimen, and from this examination to determine 'dwA.Diadema 
Desori, Forb., and D. pustidatum, Forb., are different forms of Pseiidodiadema Rhodani. 
My late esteemed colleague Dr. S. P. Woodward adopted Professor Forbes's materials in 
his " Notes on British Fossil Diadems," contributed to Decade V of the ' Memoirs of the 
Geological Survey ;' and it is evident from these notes that he had his doubts as to the 
accuracy of our lamented friend's determinations, as will appear in the description of the 
different species. 

There are two varieties of Pseudodiadema Rhodani — a large form, identical with the 
type, figured by Agassiz,^ and a smaller form, corresponding with P. Lucce. The former I have 
obtained from the Chloritic Marl of Chard ; the latter from the Upper Greensand of 
Warminster, where it appears to be rare. The fine example figured in PI. XVIII, fig. 3, 
a, h, c, is of moderate size ; the test is circular and depressed, slightly convex above, in- 
flated at the sides, and very concave below ; the ambulacral areas are large, and a little 
expanded at the sides to give increased space to the ambital tubercles ; from this point 
they taper regularly towards both poles. There are two rows of primary tubercles, from 
sixteen to seventeen in each, extending from the peristome to the disc ; three of these in 
each row, at the ambitus, are large, and all those on the upper surface small, dimi- 
nishing to mere granules near the disc (fig. 3 «); the tubercles on the under surface are small, 
and have a uniform size to the peristome ; in this region the area is filled in with several 
smaller secondary tubercles (fig. 3 b). The poriferous zones are slightly undidated at the 

1 'Description des Ecbinodermes fossiles de la Suisse,' tab. xvi, figs. 16 — 18, p. 9. 

13 



98 PSEUDODIADEMA 

sides and base ; they are composed of simple oval pores arranged in single file throughout 
(fig. 3 d). The inter-ambulacral areas one half wider than the ambulacra!, have two rows of 
primary tubercles, fourteen to fifteen in each ; a little larger at the ambitus and upper 
surface than in the ambulacra ; three pairs are much larger at the sides, those on the 
upper surface diminish rapidly in size between the ambitus and disc; and on the 
under surface they are small and nearly uniform in structure. Between the basal 
angle and the peristome there are short rows of secondary tubercles, about the size of 
the primaries in this region, with a few scattered secondaries between the lateral 
rows ; as all these small tubercles are nearly the same size, the under surface of the test 
has a highly ornamented appearance — the inter-ambulacra with four, and the ambulacra 
with two rows of small, uniform tubercles, and several secondary ones planted at every 
interval on the plates (fig. 3 3). On the upper surface the six upper tubercles are 
small, diminishing to mere granules around the discal opening (fig. 3 c). The large 
ambital tubercles are smTounded by shallow circular areolas (fig. Sd). In some specimens 
they are confluent, in others separated by one or two rows of minute granules. The 
small dorsal tubercles are surrounded by ring-like areolas, and the basal tubercles have 
a chain-like arrangement of granules encircling them, which adds to the ornamentation of 
this region. The miliary zone is very large ; from the sides to the discal aperture the entire 
surface of the plates of both areas, except those portions occupied by the areolas, is covered 
with small, numerous, close set of granules, which form divisional partitions on each side 
of the mesial sutures between the rows of the primaiy tubercles, and then expand 
into a regular corrugation on all the upper surface, the dwarfing of the tubercles being 
compensated by an increased development of granular ornamentation on this region of the 
test. The base is very concave, and the small, ch'cular peristome, indented with well- 
marked entailles, is situated at the bottom of a deep depression ; the entire surface of the 
base is studded with small tubercles, surrounded with the circles of granules already 
described. The disc is absent in all the specimens hitherto found ; the opening is large 
and pentagonal, indicating a great development of this structure in the species. 

Affinities and Differences. — P. Hhodani is readily distinguished from its congeners by 
the subundulated poriferous zones, small dorsal, intermediate basal, and large primary 
ambital tubercles, by the shortness of the secondary rows limited to the base, by the 
smallness of the dorsal tubercles and the fine homogeneous granulation on the miliary 
zone ; the concavity of the base, smallness of the peristome, and depth at which it lies, 
added to the highly ornamented character of the plates, form a group of characters 
that readily distinguish it from all others. It resembles most P. Normanics (PI. XXI, 
fig. 3), from the Grey Chalk of Folkestone, in the varied development of the tubercles 
in each row ; the ensemble of the test in the latter form is sufficiently defined by 
good specific characters, and for the definition of these I must refer to the article 
on that species. 

Locality and Strati (/rapldcal Position. — The large example I have figured was found 



FROM THE UPPER GREENSAND. 99 

in the Chloritic Marl, fall of green specks of iron, at Chard, associated with Catopygus 
carinatus, Goldf., Biscoidea subuculus, Leske, Pseudodiadema ornatum, Goldf., P. 
variolare, Brong., with Ammonites splendens. Sow., A. varians, Sow., and other forms 
characteristic of the Upper Greensand formation. The specimens from Warminster, in 
the Museum of the Royal School of Mines, and in the Collections of Mr. Soper and Mr. 
Cunnington, Devizes, were found in the Upper Greensand with P. Michelini, Agas., and 
P. Benefliw, Forb., and other common Upper Greensand forms, as Catopygiis curinatus, 
Goldf., Salenia petalifera, Agass., and Goniopyt/us peltatus, Agas., &c. &c. 

Foreign Distribution. — Geraudot (Aube) ; Perte du Rhone (Ain) ; Clars, Escragnolle 
(Var) ; very common in the Etage Albien (Cotteau). 

History. — First figured by Professor Agassiz in 1840, the large forms as Diadema 
Bhodani, the smaller as D. Luccb. After much confusion it was discovered that these 
forms are identical. Professor Forbes, from not possessing types of Pseudodiadema 
Bhodani, named the large form Diadema pustulatum, and the small ones from War- 
minster D. Desori ; this nomenclature was adopted by Dr. S. P. Woodward, in 1856, in his 
" Additional Notes on British Fossil Diadems," published in Decade V of the ' Memoirs 
of the Geological Survey.' M. Cotteau, in 1863, has given admirable figures, and a 
most correct description of the species, which my observations confirm in all their details. 



Pseudodiadema Michelini, Agassiz. PI. XIX, figs. .2, a — -f. 

Diadema Micheltni, Agassiz. Catal.Syst. Ectyp. foss. Mus. Neoc, p. 8, 1840. 

__ Agassis et Desor. Catal. rais. des fichinides, Ann. 

Sc. Naturelles, 3" ser., t. vi, p. 347, 1846. 

— — Bronn. Index Palscont., p. 418, 1848. 

— — Sorignet. Ours. foss. de dep de I'Eure, p. 25, 1850. 

— — B'Orbigwj. Prod. Paleont. strat., t. ii, p. 179, 1850. 

— BoNEi, ' Fories. In Morris's Catalogue of British Fossils, 2nd ed., 

p. 7C, 1854. 

— — O'^oorfwarrf. Mem. of Geo). Survey, Decade V.explan. of 

pl.ii, 1856. 
Pseudodiadema Michelini, Desor. Synopsis des iScliinides fossiles, p. 72, 185G. 
Diadema Michelini, Pictet. Traite de Paleont., 2' ed., t. iv, p. 245, 1857. 

Pseudodiadema pulchellum, Cotteau. Echinides nouv. ou peu connus (Revue de 

Zoologie), p. 3, pi. i, fig. 7—9, 1857. 
Pseudodiadema Michelini, Bujardin et Hup£. Hist. Nat. des Zoophytes, Echino- 

derm., p. 499, 1862. 
— Cotteau. Paleontologie Fran^aise, Terrain Cre'tncc, p. 476, 

pi. 1114, 1864. 

Diagnosis.— Test circular, or slightly pentagonal, depressed ; base flat, inflated at the 
margin, concave towards the mouth ; ambulacral areas large, two rows of prominent 



100 PSEUDODIADEMA 

primary tubercles, 12^14 in each row; interambulacral areas with two rows of primary 
tubercles, 12 — 14 in a row, and two external rows of small secondary tubercles, extend- 
ing from the peristome to the ambitus ; mouth-opening small, in a concave depression ; 
tubercles of both areas nearly the same size. 

Dimensions. — Height six tenths of an inch ; transverse diameter one inch and one 
fifth. 

Description. — This Urchin is in general of medium size, with a sub-circular or pen- 
tagonal test, convex above and flat below ; the ambulacral areas are large, slightly inflated, 
and provided with two rows of small primary tubercles, 12 — 14 in a row, rather less than 
those in the interambulacral areas, and separated by a double zigzag row of very small 
granules (fig. 2 d), gradually diminishing in size from the ambitus to both poles ; the 
poriferous zones are subflexous and composed of pairs of small round holes placed in single 
file throughout, crowded together near the peristome, and spread out above ; the inter-ambu- 
lacral areas are twice the width of the ambulacral and furnished with two rows of primary 
tubercles rather larger than those of the ambulacral areas ; they ;ire very uniform in size 
and gradually diminish from the ambitus to the poles ; between these rows and the 
poriferous zones, and between the two rows themselves, a series of small tubercles, 6 — 8 
in number, extends fi'om the peristome to the ambitus, where they disappear ; these small 
secondary tubercles fill up the intertubercular spaces at the base, and give the under sur- 
face of the test a very ornamental appearance (fig. 2 b). There are fourteen plates in each 
column of the inter-ambulacra, the primary tubei'cle occupying the centre of each ; the 
areolas are circular and superficial, the bosses prominent and sharply crenulated, and the 
mammillons large and deeply perforated (fig. 2 d) ; the surface of the plates is 
sparsely covered with small granules which form circles around the areolas and are 
scattered without order over the interspaces ; the internal borders of the four upper- 
most plates of both columns are nude (fig. 2 b) ; and the sutures distinctly visible 
throughout their entire course. The ambulacral areas have fourteen plates in each column, 
the tubercles are rather smaller than those in the inter-ambulacra, and the narrow areolas 
are separated by a zigzag line of single granules (fig. 2/), which becomes double 
(fig. 2 d) near the ambitus. The miliary zone is large, nude, and depressed at the upper 
part, granular towards the equator, and narrow and sinuous as it approaches the peristome 
(fig. 2 c). 

The mouth-opening is small, and lodged in a deep depression, the basal portion of 
the test being inflated around the peristome, which is decagonal, with nearly equal 
lobes (fig. 2 5). 

The apical disc is absent in all the specimens I have examined ; the opening, however, 
is large, a little elongated, subpentagonal, and angular (fig. 2 a). 

Jffinifics and Differences. — This Urchin is distinguished from its congeners by its in- 
flated base, depressed upper surface, simple pores,numerous primary tubercles nearly uniform 
in size and number in the columns of both areas, by its small unequal secondary tubercles. 



FROM THE UPPER GREENSAND. • 101 

extending at the base between the primaries and the poriferous zones, and by its narrow 
peristome sunk in a deep depression ; a careful comparison of typical specimens of Diadema 
Michelini, Ag., from the Upper Greensand of Villers-sur-Mer, Calvados, kindly sent by 
M. Michelin, has satisfied me that Diadema Bond, Eorb., is identical with D. Michelini; 
and that P. Benettice, Eorb. (PI. XV, fig. 2), both as regards its general form, the number, 
disposition, and character of its primary and secondary tubercles, the sraallness of the 
mouth-opening, situated in a deep depression, and the equal lobes of the peristome, is 
identical with some forms of P. Michelini oi\\\^ same size. 

Locality and Straii graphical Position. — This species is very common in the Upper 
Greensand near Warminster ; the smaller forms arc very closely allied to the Diadema 
BenetticB, Forb., the larger to the D. Bonei, Eorb. ; it has likewise been found in the same 
formation at Durdle Cove, Dorset. 

Foreign Localities. — It has been collected from the Etage Ccnomanien of France ( = 
Upper Greensand) at Villers-sur-Mer, Cauville, Vaches-Noires, Saint-Jouin (Calvados) ; 
Octeville (Manche) ; Fecamp, Orcher, Le Havre, Rouen (Mont-St.-Catherine), Seine-Infer. ; 
Vimoatiers, Grace (Orne) ; Prcsagny (Eure). 



PsEUDODiADEMA Benetti^, Forbcs. PL XV, figs. 2, a—f. 

Diadema Benetti.e, Forbes. Morris, Cat. Brit. Foss., 2nd cd., p. 7C, 1854. 

— — Woodvjard. Memoirs of tlie Gcol. Siirv., Decade V, p. 7, 

1856. 
PsECDODiADEMA Benetti.s, Besor. Synopsis des Echinides fossiles, p. 72, 1858. 

— — Bvjardin et Hvpi. Hist. Nat. des Zoophytes, EcLino- 

dermes, p. 499, 18G2. 

— Michelini, Colteau (pars). Paleontologie Fran9aise, Terrain Cretace, 

p. 476, 1864. 

Test circular, inflated, depressed; ambulacral areas wide, with two rows of tubercles 
15 in each, separated by a double row of minute granides; inter-ambulacral areas with 
two rows of primary tubercles, 14 in each; separated by a wide median space, unequally 
granulated ; miliary zone smooth above ; a few small secondary tubercles at the base ; 
primary tubercles of both areas nearly of the same size. Peristome very small, deeply 
sunk in a concave depression ; discal aperture large and pentagonal. 

Dimensions. — Transverse diameter one inch ; height four tenths of an inch. 

Description. — This beautiful little Urchin was formerly considered to be the Diadema 
ornatum, Goldf., and recorded as such in the first edition of jMorris's ' Catalogue of 
British Fossils.' It was subsequently considered by Professor Forbes to be a distinct 
species, and in the second edition of that work was dedicated by him to the late Miss 



102 PSEUDODIADEMA 

E. Benett, of Norton House,* Wilts. It was first accurately described by the late Dr. 
Woodward in his Notes on Fossil Diadems. 

The test is circular, depressed on the upper surface, concave below, and inflated at the 
sides. The ambulacral areas are proportionally wide, with two rows of tubercles separated 
by a double row of granules ; there are from 12 — 15 in each row, according to age ; they in- 
crease gradually in size, from the peristome and disc towards the ambitus, where they are 
largest; the poriferous zones are narrow and slightly undulated; the pores are in oblique single" 
file throughout, three pairs of holes being opposite each ambulacral plate (fig. 2 a), where 
they are magnified four diameters ; the pores at the circumference have a small tubercle 
between each pair ; the inter-ambulacral areas are about one fourth part wider than the 
ambulacral; they have two rows of tubercles, from 12 — 14 in each, separated by a wide 
miliary zone, which is unequally granulated, and becomes smooth on the upper surface ; 
a similar sparsely granulated space separates the tubercles from the poriferous zones ; 
and at the base of the area a short row of small secondaiy tubercles extends from 
the peristome to the angle, between the large tubercles and the poriferous zones. The 
tubercles of both areas are nearly of the same size, those of the inter-ambulacral are 
the largest; they have all distinct oval areolas, which are sometimes radiated, and 
encircled by rows of very small granules. The base is inflated at the circumference, 
and concave in the middle ; the peristome is small and deeply sunk, about one third the 
diameter of the test ; its margin is divided by feeble entailles. The disc is absent in all 
our specimens ; the aperture is wide and pentagonal, the angles pointing towards the 
median suture of the inter-ambulacral areas. 

JMnilies and Differences. — This species so much resembles Pseudodiadema Michelini, 
A"-., that it has been considered by some authors to be the same. M. Cotteau says, " P. 
Michelini, such as we understand it, cannot be distinguished from P. Benettice, Eorb., and 
we do not hesitate to unite the two species, which present in their form, in the disposition 
of their tubercles, in the structure of their peristome, in a word, in the ensemble of their 
characters, an identity almost complete." Admitting, as I do, the great similarity of the 
tests of the two forms, still I think, by a careful study of both, we can detect characters 
which may justify us in retaining our lamented colleague's species. P. Benett ia has the 
tubercles smaller, the sides more inflated, the circumference of the base more convex, and 
the mouth-opening smaller and lodged in a deeper depression. P. Michelini is a flatter 
Urchin and the size and greater prominence of the tubercles impart to it a more spinous 
character ; if these points of diS"ercnce in the test are borne out by any corresponding 
difi"erence in the spines, the species may be sustained ; if not, P. Bennetice may turn out to 
be a mere variety of P. Michelini. 

Locality and Stratigraphical Position. — This is a very abundant species in the 
junction-beds of the Upper Greensand at Warminster, associated with P. Michelini, 

' Authoress of ' A Catalogue of WiltsLirc Fossils,' 1831. 



FROM THE GREY CHALK. 103 

Catopygus carinatus, and the other species of this zone. It has been collected from the 
same beds at Durdle Cove, on the Coast of Dorset. 

Foreign Distribution. — M. Desor states that F. Benettice is found in the Craie 
chloritee (Cenomanien) of Villers-sur-Mer, Vaches-noires, de Gace, Orne, and is common 
in all French collections. 



D. Species from the Grey Chalk. 

PSEUDODIADEMA ORNATUM, Goldf., Sp. PI. XVI, figS. 4 a 6; PI. XIX, flgS. 1 a — C ; PI. 

XXI, figs. 1 a—d, 2; PI. XXI a, figs. 1 a, h. 

CiDAEiTES OKNATUS, Gold/uss. Petref. GerraauiiB, tab.xl, fig. 10, p. 123, 1826. 

DiADEMA OKNATUM, Agassiz. Prod, d'une Monogr. des Radiares, Mem. Soc. 

des Sc. Nat. de Neufchatel, t. i, p. 118, 1836. 

— — BesmouUns. Etudes sur les Echinides, p. 314, No. 15, 1837. 

— — Dujardin. InLamarck'sAnim. sans Vertebras, 2° ed., t. iii, 

p. 392, 1840. 

— — Roemer. Norddeutschen Kreidegebirges, p. 29, 1840. 

— — Agassiz et Desor. Catalogue raison. des Echinides, Ann. 

Sc. Nat., 2' ser., t. vi, p. 347, 1846. 

— — Brorm. Index Palaeont., p. 449, 1848. 

— — jyOrbigny. Prod, de Paleont. strat., t. ii, p. 169, fit. 20, 

No. 560, 1850. 

— — Forbes. In Morris's British Fossils, 2nd ed., p. 77, 1854. 

— — McCoy. Contributions to Brit. Palseontology, p. 67, 1854. 

— — Desor. Synopsis des Ecbinides fossiles, p. 72, 1856. 

— — Woodward. Mem. of Geol. Surv., Decade V, p. 7, 1856. 

— TUMIDUM, Woodward. Mem. Geol. Surv., Decade V, 1856. 

— CAETERI, Woodward. Ibid. 

PsEUDODiADEMA ORH ATm\, Pictet. Traite de Paleontol., 2' ed., t. iv, p. 245, 1857. 

— — Dujardin et Hupe. Hist. Nat. des Zoophytes, Echinod., 

p. 499, 1862. 

— — Cotteau. Paleontologie Frangaise, Terrain Cretace, pi. 1115, 

tom. ii, p. 480, 1864. 

Test circular, inflated ; ambulacral areas straight ; tubercles small, numerous, sub- 
equal, in two rows, separated by a double series of granules; inter-ambulacral areas 
with two rows of tubercles, separated by four rows of granules at the ambitus, which 
disappear at the upper surface, and leave a smooth depressed space in the middle of the 
miliary zone, bordered by two rows of granules; between the tubercles and poriferous 
zones a row of secondary tubercles extends from the peristome to near the disc, consisting 
of small well-spaced-out tubercles, each surrounded by a circle of granules. Areolas cir- 
cular, many of them radiated ; tubercles of both areas nearly equal in size. 

Dimensions. — Height half an inch ; transverse diameter one inch and two tenths. 



104 PSEUDODIADEMA 

Descri])tion. — This beautiful Urchin when full grown is moderately large ; it has a 
circular, elevated, and inflated form, depressed on the upper surface, and concave beneath. 

The ambulacral areas are large, a little inflated, and furnished with two rows''of 
moderately sized tubercles, 14 — 16 in a row; one of these is always longer than the 
other, and separated from its fellow by a double series of small compact granules. The 
poriferous zones are straight and narrow at the base of the test, and gently subun- 
dulated from the ambitus to the apical disc ; they are composed of simple pores closely 
approximated to each other ; the pairs are well spaced out in the infra-marginal region, 
closer together at the equator, and still closer placed near the disc. PI. XXI, figs. 1 b, c. 

The inter-ambulacral areas are large, and provided with two rows of tubercles, nearly 
identical in size with those of the ambulacral areas at the base and ambitus of the 
same regions ; in the upper part of the area, however, they are proportionally larger, 
so that we find only 13 — 15 tubercles in each row. The secondary tubercles form a 
distinct series of from seven to nine small tubercles, situated between the primary row 
and the poriferous zones ; in general one small tubercle arises from each plate between 
the peristome and ambitus (PI. XIX, fig. 1 (/), and is absent from the three or four upper 
plates of the test (PI. XVI, fig. 4 e) ; besides these, there are other smaller tubercles, of 
unequal size, scattered between the primary and secondary rows (PI. XIX, figs. 1 b, c, d). 

The miliary zone is very wide; it is narrow near the peristome, enlarged at the 
ambitus, and nude and depressed on the upper surface (PI. XVI, figs. 4 c and e). The 
granules are numerous, unequal, sometimes mammillated, and distinguished with difficulty 
from the small secondary tubercles among which they are interspersed (PI. XXI, figs. \ a,c; 
PI. XVI, figs. 4 c, ^). 

The primary tubercles of both areas have well-defined circular areolas, prominent 
bosses, with sharply crenulated summits, and large mammillons with deeply drilled summits ; 
the inter-ambulacral are a little larger than those of the ambulacral areas. The areolas near 
the ambitus are mostly confluent above and below, whilst on the upper surface of the inter- 
ambulacra they are distinct, and surrounded by circles of small granules (PL XXI, fig. 1 c). 

The under surface is convex at the circumference, with a deep depression in the 
middle, in which the mouth-opening is situated. The peristome is very small, and its 
margin feebly indented. The discal opening is large, elongated, and sub-pentagonal. 
Unfortunately, all the specimens hitherto found want the discal plates (PI. XIX, fig. 1 b). 

Affinities and Differences. — This Urchin resembles P. Michel i iii ; it is, however, distin- 
guished from that species by its much greater height, inflated sides, narrow base, 
slightly undulated poriferous zones, more numerous and better developed secondary 
tubercles, more deeply sunk peristome, and elongated discal opening; these diagnostic 
characters are not the result of age, as they are observed more or less in comparing 
young specimens of both species apparently of the same age with each other. 

Localifi/ and Stratigraphical Position. — The specimens figured, from the Grey 
Chalk, Folkestone, on Pis. XVI, XIX, and XXI a, belong to the Rev. T. Wiltshire, the 



FROM THE GREY CHALK. 105 

British Museum, and my cabinet. I have examined a specimen from the Red Chalk of 
Hunstanton Cliff, belonging to my friend C. B. Rose, Esq., F.G.S., who has most kindly 
communicated many of his Echinodermata for this work. The specimen figured in 
PI. XXI, fig. 1, now in my cabinet, was collected from the remarkable bed of Chloritic 
Marl at Chard, which has yielded so many fine examples of Echinidce. The specimen in 
the Cambridge Museum is recorded by Professor McCoy as having been collected from 
the Upper Greensand of Blackdown. Many of the specimens sent me as P. Carteri 
by my friend Mr. J. Walker, F.G.S., and collected by him from the copvolite beds of the 
Upper Greensand near Cambridge, are undeniable specimens of P. ornahun. 

Foreign Distribution. — Frcmce. — Rouen, Mountain of St. Catherine, Seine-Inferieure ; 
Vimoutiers (Orne), in the Btage Ccnomanien, where it is rare. Germany. — Essen-on-the- 
Ruhr, Westphalia, whence Goldfuss's type specimen was obtained. 

Histori/. — This Urchin was first figm'ed and described in the ' Petrefacta Germanise' by 
Goldfuss, in 1826, under the name Cidarites ornatus. Professor Agassiz, in 1836, 
erroneously referred to this species a small Neocomian form, which was subsequently 
separated under the name Diadema Bouryueti. In the first edition of the ' Catalogue of 
British Fossils,' Diadema Benettice was recorded as D. ornatum on the authority of 
Dr. Woodward. Professor Forbes named the tumid varieties of this Urchin Diadema 
tumidum, and under this name they are described, from type specimens, in my cabinet 
(PI. XXI, fig. 1), by Dr. S. P. Woodward, in his " Notes on British Fossil Diadems," con- 
tributed to Decade V, ' Memoirs of the Geological Survey.' 



PSEUDODIADEMA NoRMANIiE, Cotteaii, 18C3. PI. XXI, fig. 3, a, d. 

PsEUDODiADEMA NoRMANiyE, Cotteau. Paleontologie rran9aise. Terrain Cretace, t. vii, 

p. 4G8, pi. 1112. 

Test of moderate size, subcircular, inflated at the sides, and convex above ; base rounded 
at the margin, and very concave in the centre ; ambulacral areas wide, with two rows of 
tubercles, large at the ambitus and small on the upper and infra-marginal regions, sepa- 
rated by several rows of minute unequal granules ; inter-ambulacral areas narrow, with 
two rows of primary tubercles, nearly similar in size and development to those of the 
ambulacra, and numerous small, unequal, secondary tubercles, forming in the infra-mar- 
ginal region six short series, two on each side, and two in the middle of the primary 
rows ; mouth-opening lodged in a deep depression. 

Dimensions. — Height six tenths of an inch ; transverse diameter one inch and four tenths. 

Description. — This rare and beautiful Urchin is of medium size ; it has a subcircular 
form, with broad inflated sides, convex at the upper surface and very concave beneath. The 
ambulacral areas are wide in the middle, lanceolate in the upper part, and narrow in the 
infra-marginal region ; they have two rows of primary tubercles, of which two pairs at the 

14 



lOG PSEUDODIADEMA 

ambitus are very largely developed, and occupy the greatest part of the area, having large 
areolas, prominent bosses, sharply crenulated summits, with projecting, deeply perforated 
mammillons (PI. XXI, fig 3 d) ; on the upper surface they rapidly diminish in size ; four of 
them have small areolas and the others become mere granules. In the infra-marginal region 
they gradually diminish as they approach the peristome, where two short rows of secondary 
tubercles are regularly arranged. The primary tubercles are separated by two rows of very 
fine granules, which gradually increase in number, and fill the entire upper portion of the 
area (fig. 3 d). 

The poriferous zones are narrow and straight at the base, undulated on the sides, and 
straight again on the upper surface ; the pores are simple, round, largely open, and 
arranged in a single file throughout (fig. 3 c and d). 

The inter-ambulacral areas are relatively small from the excessive width of the ambu- 
lacra ; they have two rows of primary tubercles, of which three pairs at the ambitus, like 
those in the ambulacral areas, attain a great development ; above they become suddenly 
smaller, and diminish to mere granules ; and on the infra-marginal region they become 
gradually smaller as they approach the peristome. The secondaiy tubercles are very abun- 
dant, and limited to this region of the test ; at the base of each interambulacra there are 
six short rows, a long and a short row between the zones and the tubercles on each side, 
and two short rows between the tubercles themselves. This great profusion of small 
secondary tubercles and diminished size of those in the primary series impart to the base 
of the test of this Urchin a remarkable ornamental appearance, which resembles, on a larger 
scale, the structure of the base in P. JRJiodani (fig. 3 h). 

The miliary zone is largely developed ; the two primary rows of tubercles at the 
ambitus have six rows of granules forming a band between them ; in the upper part the 
gi-anulation increases, and fills the whole zone, except the part occupied by the areolas of 
the small rudimentary tubercles, forming circles around them, and filling the whole space 
with a fine nearly uniform granulation. 

The base is very concave and crowded with small tubercles ; the mouth-opening is 
small, and lies at the bottom of a very deep depression ; the peristome is narrow, and 
marked by feeble indentations. 

Affinities and Differences. — This remarkable species resembles P. Itliodani in having its 
base crowded with numerous small tubercles, and in having large tubercles at the ambitus, 
and rudimentary ones on the upper surface. Its form, however, is always inflated ; the 
poriferous zones are straight at the base and upper surface, and undulated at the ambitus. 
The secondary tubercles are larger and more numerous, and distinguished with difficulty 
from those of the primaiy rows of the imder surface. 

Locality and Stratigrapldcal Position. — The only specimen I have seen was obtained 
from the Grey Chalk near Folkestone by the Rev. T. Wiltshire, to whose cabinet it 
belongs. — Foreipi Distribution. — M. Cotteau records Yimoutiers (Orne), in the Etage 
Cenomanien, where it is very rare. 



PROM THE GREY CPIALK. 



107 



PSETJDODIADEMA .ARioLARE, Brongniart, sp., 1822. PI. XVII, figs. 1-5 ; XVIII, 

figs. 1, 2. 



Bronyniart. Geog. phys. des env. de Paris, pi. v, fig. 9, 
1822; Tableau des Terrains, p. 408, 1829 ; Desc. 
g^ol. des eiiy. de Paris, 3' edit., pi. xvii, fig. 9, 1835. 

Agassiz. Prod, d'une Monogr. des Radiaires, p. 189, 

1836. 
Boemer. Norddeutsclien Kreidegebirges, p. 29, 1840. 
Morris. Catalogue of British Fossils, p. 51, 1843. 
Agassiz ttHesor. Catalogue rais. des Echinides, Ann. 

des Sc. Nat., 3= ser., t. vi, p. 350, 1846. 
Agassiz et Ttesor. Ibid. 
Agassiz et Desor. Ibid. 

Bronn. Index Paleeontologicus, p. 1261, 1848. 
A. Gras. Oursins foss. de I'Isfere, p. 33, pi. ii, fig. 16, 

1848. 
D'Orbigng. Prod, de Paleout. strat,, t. ii, p. 179, 1850. 
D'Orhigmj. Ibid., t. ii, p. 201. 
Sorignet. Ours. foss. de I'Eure, p. 26, 1850. 
B'Archiac. Hist, des progres de la Geol., t. iv, p. 215^ 

1851. 
Quenstedt. Handbuch der Petrefaktenkunde, p. 580, 

1852. 
Giehel. Deutschlands Petrefacten, p. 319, 1852. 
Forbes. In Morris's Catalogue of British Fossils, 2nd 

ed., p. 77, 1854. 
Forbes. Ibid. 
Besor. Synopsis des Echinides fossiles, p. 78, 1856. 

Besor. Ibid. 
Besor. Ibid. 
Woodward. Mem. Geol. Survey, Decade V, 1856. 

Woodward. Ibid. 

Pictef. Trait6 de Paleont., T ed., t. It, p. 215, 1857. 

Pictet. Ibid. 

Coquand. Synop. des Foss. Cretaces, Bulletin See. 
Geol. de France, 2' s6r., t. xvi, p. 992, 1859. 
— SUBNUDTJM, Coqitand. Ibid. , , q .u 

PsErDODiADEMASTUiATTTLUM, Cotteau et Triger. Echin. du depart, de la Sarthe, 

p. 144, pi. xxxvii, figs. 13 — 15, 1859. 
PSEUDODIABEMA RoissYi, Cotteau ti Triger. Ibid. 

DiPLOPODiA VAKioLABis, Coquand. Cat. rais des Foss. depart. Charente, p. 15o, 

1861. 



CiDABITES VARIOLARIS, 

DiADEMA VAKIOLARE, 

CiDARITES TABIOLARIS, 
DiADEMA VARIOLABE, 



— SUBNUDUM, 

ROISSYI, 

Tetragramma variolare, 

DiADEMA — 

— SDBNUDUM, 

KOISSYI, 

Tetagramma subnddtjm, 
cidabis variolaris, 

DiADEMA VARIOLARE, 

Tetkagramma — 

DiADEMA SUBNUDUM, 

— VARIOLARE, 
DiPLOPODIA VARIOLARIS, 

SDBNUDA, 

RolSSYI, 

DiADEMA VARIOLABE, 

SUB-NUDUM, 

ROISSYI, 

DiPLOPODIA VARIOLARIS, 



108 PSEUDODIADEMA 

DiPLOPODiA SUBNUDDM, Coquaitd. Ibid. 

— VAUioLARis, Bujardin et Hupe. Hist. Nat. des Zooph. Echinoderraes, 

p. 501, 1862. 

— SUBNUDA, Dvjardin et Hupe. Ibid. 

— STEIATULUM, Dujardiii et Hupe. Ibid. 

PsEUDODiADEMA VAKIOLARE, Cotteau. Pak'ontologie Fran9aisp, Terrain Crc'tace, t. vii, 

p. 488, pis. 1117, 1118, lll!),and 1120,figs. 1—3, 1864. 

Test large, subcircular, slightly subpentagonal, nearly equally depressed on the upper 
and under surfaces. Ambulacral areas narrow and contracted at the upper part by the 
poriferous zones; two rows of tubercles, 15 — 17 in each series, separated by a single line 
of granules ; pores round, in oblique single pairs in the middle, widely bigeminal on the 
iipper surface, and trigeminal near the peristome. Inter-ambulacral areas wide, with 
four rows of primary tubercles and two short rows of small secondary tubercles. The 
middle of the upper surface of the area nude and often depressed. Under surface convex, 
mouth-opening small ; peristome with feeble entailles. Discal opening large, sharply 
angular, pentagonal. 

Dimensions. — a. — Height half an inch ; transverse diameter one inch. b. — Height 
half an inch ; transverse diameter one inch and a half. 

Description. — The identity of this species has long been uncertain from the impos- 
sibility of ascertaining the Urchin intended by the figure and description given by 
Brongniart, without reference to the type specimen ; this comparison has now fortunately 
been made by M. Cotteau, who has given admirable figures and most ample descriptions 
of the various forms P. variolare exhibits under different conditions of age and habitat. I 
shall first describe the general characters of the species, and secondly point out the three 
chief varieties it assumes. 

The test is of medium size, subcircular, sometimes lightly pentagonal, and equally 
depressed at both poles. The ambulacral areas are narrow, and contracted at their upper 
part bythe excessive development of the poriferous zones in this region; they possess two rows 
of large tubercles, 15 — 17 in each series, according to size and age, which gradually diminish 
in size from the equator to the peristome, and become small and rudimentary on the upper 
surface (PI. XVII, fig. 3 a). The rows are closely approximated, there being only a single 
series of small granules, of unequal size, forming a zigzag line, between them ; the 
tubercles have narrow areolas, prominent bosses, with sharply crenulated summits, and 
deeply perforated mammillons (fig. 4). The poriferous zones are narrow, the pores 
round, in single oblique pairs on the sides, in triple oblique pairs near the peristome, and 
they are widely bigeminal in all the upper fourth of the zones (fig. 5 a). 

The interambulacral areas are nearly four times as wide as the ambulacral in the spe- 
cimen figured in PI. XVII, figs. 3 a, h, c, rather more than one inch in diameter. There 
are four rows of large tubercles, and two secondary rows, at the ambitus ; the two inner 
primary rows, with fourteen tubercles in each series, extend from the peristome to the apical 



FROM THE GREY CHALK. 109 

disc, and the outer primary rows are absent from the three uppermost plates (fig. 3 a). In a 
large specimen from the Chalk-Marl of Dorset, b, one and a half inches in diameter, the 
ambital plates have six and eight rows of large tubercles, and two rows of small secondary 
tubercles. There are sixteen tubercles in each inner series which alone reach the disc, 
the second, third, and fourth rows disappear as the plates shorten on the upper surface. 
The small secondary tubercles, situated near the poriferous zones, form a short series 
between the peristome and equator; they are scarcely larger than granules, but are, 
nevertheless, mammillated and perforated, and their presence, position, and development, 
constitute one of the specific characters of this Urchin. The interambulacral tubercles 
are nearly identical in size with those of the ambulacral areas (fig. 4). They have narrow 
areolas, prominent bosses, with sharply crenulated summits, and large perforated mamil- 
lons. The miliary zone is narrow at the sides and infra-margin, with two rows of granules 
of unequal sizes ; at the upper surface it becomes nude and depressed (fig. 3 a) around tlie 
discal opening, a character which appears in excess in the var. suhimdum. A number 
of granules, of different sizes, form hexagonal circlets around the areolas (fig. 5 a). 

The under surface is convex, and the small mouth-opening occupies a slight depres- 
sion ; the peristome is circular, and its margin notched with feeble entailles (fig. 3 b). The 
opening for the apical disc was very large (fig. 3 a), widely pentagonal, and sharply angu- 
lar, extending into the nude portion of the inter-ambulacra. None of the specimens as yet 
found contain any of the discal plates. (See likewise PL XVHI, figs. 1 a, h, and fig. 2). 

Authors have recognised three distinct forms of this species, which some have de- 
scribed as so many separate species, whilst others regard them as varieties of one. 

1st. Var. a, variolar e, identical with Brongniart's type form, is found in the Upper 
Greensand of Wiltshire and the " Chloritic Marl " of Chard (PI. XVIH, fig. 2) and I'Etage 
Cenomanien of Villers-sur-Mer, Calvados, Prance, from which localities I have specimens. 
Its upper surface is more or less depressed, and its outline is circular or subpen- 
tagonal. The inter-ambulacra have four rows of primary and two rows of small secondary 
tubercles ; the under surface is convex, and the mouth-opening small. 

2nd. The var. h, subnudum, has the upper surface remarkably nude, from the ab- 
sence of granules in the upper part of the miliary zone ; the test is higher, and my 
specimen from the " Chloritic Marl " of Chard has a thicker structure than var. a. 

3rd. The var. c, Boissi/i, is still higher and much larger than var. b ; it has a more 
tuberculous appearance, and from six to eight rows of tubercles in the inter-ambulacra. I 
have two specimens before me that agree very well with M. Desor's diagnosis of this 
form, which he considers a good species, or at all events a large variety of P. subnu- 
dum. After a critical study of all these forms, I can find no good structural character for 
separating them, and therefore consider them as varieties of P. variolare, depending on 
age or habitat for the differences they exhibit in the size, thickness, and number of tuber- 
cles in the inter-ambulacral areas. 

AJuiities and Differences, — Pseudodiadema variolare is one of the most perfect types of a 



no PSEUDODIADEMA 

tetragrammous Diadema with bigeminal pores. It very much resembles P. Brongniarti, 
Agas., from the Grey Chalk, but is distinguished from the latter by having its upper and 
under surfaces more depressed, the ambulacral areas narrower, their rows of tubercles 
shorter, and those on the upper surface more rudimentary; the poriferous zones are much 
wider on the upper foiu-th, and have the pores more largely bigeminal ; the base likewise 
is more convex, wider, and less contracted than in P. Brongniarti. 

Locality and Stratigraphical Position. — P. variolare is found in the Upper Greensand 
of Warminster, and the " Chloritic Marl " near Chard ; from the latter locality I have 
specimens that represent the var. h., subnudam, and var. c, Boissi/i. The large specimen 
was kindly communicated by the Rev. C. W. Bingham, of Binghams Melcombe, near 
Dorchester; it was collected from the Upper Greensand of that neighboui'hood — the 
precise locality is not recorded. 

Foreign Localities. — M. Cotteau has given a wide range to the distribution of this 
species in France, and records — " Villers-sur-Mer, Cauville, Vaches-Noires, Dives, Saint- 
Jouin (Calvados) ; Octeville (Manche) ; Fecamp, Le Havre, Rouen (Seine-Infcrieure) ; 
Vimoutiers, Grace, La Perriere (Orue) ; Presagny pres Vernon (Eure) ; Berneuil (Oise) ; 
Grandpre (Ardennes) ; La Fauche pres le Villard-de-Lans (Isere) ; Le Mans, La Raglasse, 
Yvre-l'Eveque (Sarthe) ; Corze (Maine et Loire) ; Touvois (Loire-Inferieure) ; Angouleme 
(Charente) ; ile Madame, Saintes (Charente-Inferieure). Assez abondant. Etage Ceno- 
manien, commun surtout dans la zone a Scapldtes ceqiialis. — Lillebonne (Seine-Inferiem'e). 
Rare. Etage turonien." 

In the Hils conglomerate, near Essen, Hanover. Desor. 

Uistorg.- — Figured for the first time by Brongniart in 1822, as Cidarites variolaris,m 
his ' Geognosie Physique des Environs de Paris,' from a specimen collected at Havre in 
the Upper Greensand. 

In the ' Catalogue raisonne des Echinides,' 1846, MM. Agassiz and Desor separated 
certain varieties of this species from the type which they found in the museums of France, 
under the names Diadema subnudum and D. Boissgi ; those, however, I have endeavoured 
to demonstrate are merely varieties of P. variolare. 



FROM THE GREY CHALK. HI 



PsEUDODiADEMA Brongniarti, Ayasisiz, 1840. PI. XX, fig. 2 a — c; XXI a, figs, i 

a—f, 3, 4 ; XXI B, figs. 1—3 a—e. 

Tetkagramma Brongniarti, Agassi:. Desc. des Echinides fossiles de la Suisse, t. ii, 

p. 25, pi. xiv, figs. 4—6, 1840. 

— — Agassiz et Besor. Catal. rais. des Echinides, Ann. Sc. 

Nat., 3e ser., t. vi, p. 350, 1846. 

— — Bronn. Index Palseontologicus, p. 1261, 1849. 
Diadema — D'Orbigny. Prodrome, t. ii, p. 142, Et. 19, No. 328, 

1850. 

— — Renevier. Mem. Geol. sur la Perte du Rhone, p. 32, 

1853. 

— — Forhes. In Morris's Catalogue of British Fossils, 2nd 

ed., p. 76, 1854. 
PsEUDODiADEMA — Desor. Synopsis des Echinides fossiles, p. 74, 1856. 

Diadema — Woodward. Mem. of the Geol. Surv., Decade V, 1856. 

_ _ Pictet. Traite de Paleontol., 2e ed., t. iv, p. 244, 1857. 

Pseldodiadema — Bvjardin et Hitpi. Hist. Nat. des Zoophytes, Echino- 

dermes, p. 498, 1862. 
— — Cotteau. Paleontologie Francaise, Terrain Cretace, t. vii, 

p. 456., pi. 1109, 1865. 

Test large, subcircular, elevated; sides tumid, depressed at the upper surface, narrow, 
rounded, and contracted on the under surface ; ambulacral areas narrow, with two rows of 
tubercles, separated by a double series of small granules of unequal sizes; poriferous zones 
narrow, straight ; pores round, in single pairs from the peristome to the ambitus, and 
bigeminal thence to the disc-opening ; inter-ambulaeral areas wide, with four rows of 
primary tubercles, nearly identical in size with those of the ambulacra, and two short 
rows of very small secondaries near the zones. Mouth-opening small, in a considerable 
depression ; peristome narrow, with feeble and nearly equal-sized entaillcs. 

Dimensions. — a. — Height six tenths of an inch ; transverse diameter one inch and a 
half. B. — Transverse diameter two inches and a half. 

Description. — The test of this species exhibits so close a resemblance in many of its 
anatomical details to that of Pseudodiadema variolare, that, were it not for some differences 
in the size, shape, and development of the shell, and in the structure of the ambulacra, I 
should hesitate to separate it from that form ; after all, these differences may not be 
specific, but may have arisen from habitat and other physical conditions. A test of each 
species, with spines attached, for the purpose of comparison, is still with me a desideratum ; 
however, as this Urchin is considered by most authors to be distinct from P. variolare, I 
shall describe the fossils I have figured under the name P. Bronpiiarti, Agas. These 



113 PSEUDODIADEMA. 

specimens have been compared with typical examples from the Upper Greensand of 
the Perte du Rhone, and identified as the true forms of P. Brongniarti, Agas. 

The test is moderately large, sub-circular, and elevated ; the sides are tumid, and the 
upper surface is flat ; the base is convex, contracted at the circumference, and having the 
peristome sunk in a considerable depression (PL XXI a, fig. 2 c). The ambulacral areas are 
narrow, and sharply lanceolate ; they have two rows of primary tubercles, from sixteen to 
seventeen in each row, which diminish gradually from the ambitus to the peristome and 
the disc j they are placed closely together, and have narrow ring-like areolas ; the bosses 
are stout, with sharply crenulated summits, and the mammillons are large and perforated 
(fig. 2 e) ; a row of granules, of unequal sizes, sometimes mammillated, separates the 
tubercles at the middle and base of the area, whilst in the upper part branches of fine 
granules pass off horizontally, forming circlets around the tubercles (fig. 2 e). The 
poriferous zones are narrow ; the pores are in single pairs in the middle and infra-marginal 
region, near the peristome they lie in triple oblique pairs, above the ambitus they fall out of 
their regular ranks, and at the upper surface are distinctly bigeminal (PI. XXI a, fig. 2 h). 

The inter-ambulacral areas are more than twice the width of the ambulacral ; they 
have four rows of primary tubercles nearly identical with those in the ambulacra. The 
two inner rows are best developed, and extend from the peristome to the disc, whilst the 
external rows are absent from the three uppermost plates ; in the large specimen there 
mustha\'e been sixteen to eighteen tubercles in each internal row (PI. XX, figs. 2 a and h) ; a 
series of small unequal secondary tubercles ascends from the peristome to above the ambitus, 
situated between the primary tubercles and the zones (PI. XXI a, figs. 2 d, e) ; they are 
altogether absent from the upper surface, but constant in the region I have described. 
The miliary zone is narrow in the infra-marginal region, wider in the middle, and 
expands at the upper surface ; it is filled with four rows of small irregular granules, among 
which a number of small mammillated tubercles as large as the secondaries are placed (PI. 
XXI A, fig. 2 e) ; above the ambitus horizontal branches of granules extend from the median 
rows, separating the areolas, and forming hexagonal divisions between them (fig. 2 e) ; 
at the upper fourth of the area the granules disappear from the middle of the zone, and a 
triangular nude space is exposed, having its base at the disc and its apex at the fifth 
plate ; the circlets of granules are absent from the areolas of these plates. 

The upper surface is flat, and the opening for the apical disc large and pentagonal, the 
angles extending into the inter-ambulacra (fig. 2 6.) 

The base is convex and contracted at the side ; the centre is concave, about one third 
the width of the shell, and the mouth-opening lies in a considerable depression ; the 
peristome is small, about one third the width of the shell ; in a fine test showing the base 
one and a half inch in diameter ; that of the peristome is half an inch (fig. 2 c). 

Affinities and Differences. — P. Brongniarti is distinguished from its congeners by 
its elevated test, with tumid sides, flat upper surface, and contracted, convex under 
surface. 



THE 



paltEontographical society. 



INSTITUTED MDCCCXLVII. 



VOLUME FOE 1869. 



LONDON: 

MDCCOLZX. 




A MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODERMATA 



FROM 



THE CRETACEOUS FORMATIONS. 



THOMAS WRIGHT, M.D., F.R.S. Edin., F.G.S., 

CORRESPONDING MEMBER OF THE ROYAL SOCIETY OF SCIENCES OF LIEGE, THE SOCIETY OF 
NATURAL SCIENCES OP NEUFCHATEL, AND SENIOR SURGEON TO 
• THE CHELTENHAM HOSPITAL. 



VOLUME FIRST. 

PART THIRD. 
ON THE DIADEMADiE. 

Pages 113—136 ; Plates XXU— XXIX, XXIXa, XXIXb. 

LONDON: 

PRINTED FOR THE PAL^ONTOGRAPHICAL SOCIETY. 

1870. 



PBIHTBD BT 
.T. E. ADLAHD, BARTHOLOMEW CLOSE. 



FROM THE GREY CHALK. 113 

The pores are scarcely bigeminal near the summit. The primary tubercles are 
numerous, nearly uniform in size, and closely set together ; the mouth-opening is very 
small, and lies in a deep depression. 

Pseudodiadema variolare has the test in general more depressed, the base wider, and 
the pores more distinctly bigeminal in the upper fourth of the zones ; the base is wider, 
more convex, and less contracted than in Ps. Bronpniarti. 

LocalHy and titrati(/raphical Position. — Pseudodiadema Bron(jniarti has been col- 
lected from the Grey Chalk near Folkestone, from which stratum all the large tine speci- 
mens in the British Museum, and those in the Rev. T. WiUshire's cabinet figured in 
this Monograph, have been obtained. The Red Chalk of Hunstanton Cliff has yielded 
a few examples, two of which, from Mr. Rose's and the Rev. T. Wiltshire's collections, 
are figured in PI. XXI b. Forms referred to this species have been collected from 
the Chalk-marl of Maiden Bradley, Dorset, and the Chloritic Marl, Somerset. 

Foreign Localities. — Professor Pictet, of Geneva, kindlv gave me several type speci- 
mens of this Urchin collected from the Gault of the Perte du Rhone (Ain), which so much 
resemble Professor Agassiz's figures of this species from the same locality that my speci- 
mens might have been the originals of the drawings in his ' Bchinodermes foss. de la 
Suisse.' It is found likewise at Escragnolle (Var), Montngne des Fis (Savoie), where it is 
an abundant fossil in the Etage Albien or the Gault. M. Desor, in addition to these 
localities, gives Clar and La Presta, as places where this species is abundant. 

History. — First figured by M. Al. Brongniart^ in his ' Description de la Perte du Rhone,' 
under the name Cidariles variolaris {?), as a characteristic fossil of the Craie INIarneuse ; 
afterwards (1S40) it was described and figured by Professor Agassiz in the ' Echinodermes 
foss. de la Suisse' as Tetrngramma Brongniarti ; afterwards (1856) it was removed by 
M. Desor into his genus Pseudodiadema, where it now remains. 



Genus — Pedinopsis, Cotteau, 1803. 

Test large, round, inflated, sometimes subconical. Poriferous zones wide and straight ; 
the pores bigeminal throughout, forming at the upper surface and ambitus two distinct 
rows, which become more blended together at the infra-marginal region, and are distinct 
at the base. Tubercles of both areas small, and nearly the same size ; summit of the 
boss finely crenulated, and the raammillon perforated ; the tubercles disposed in regular 
rows, the number varying in the different species, and always diminishing as they 
approach the summit ; coronal plates long, narrow, and granular ; mouth-opening large, 
peristome moderately developed, circumference slightly incised, apical disc small, sub- 
circular, elements feebly united, absent in the specimens known. 

' 'Description geologique des Environs de Paris,' troisieme edition, 1835, p. 174, pi. m, fig. 9. 

15 



114 PEDINOPSIS 

This genus was established by M. Cotteau in his memoiri on ' Les Echinides 
des Pyrenees,' and placed near PseudocUadema, with which it has many affinities ; the 
tubercles are crenulated and perforated, and the pores bigeminal throughout, a character 
which is in part possessed by Ps. Broiipnarfi, variolare, &c. It has affinities with 
Salmacis in the number of its pores ; in this genus, however, they are arranged in triple 
oblique pairs, whilst in Pedinopsis they are regularly bigeminal throughout. 

The original specimen was collected from the Neocomian strata of Aude, where it is 
rare ; another of the same species has been found at Caussols (Var) ; the one which I 
now figure was obtained from the Chloritic Marl near Chardstock, Somerset. 



Pedinopsis Wiesti, WrigJd, nov. sp. PI. XIV, fig. 1 ; PI. XXIX a. 

Test moderate in size, circular, inflated at the sides, convex on the upper surface, and 
fiat at the base ; ambulacra with two complete marginal rows and two inner incomplete 
rows of tubercles ; inter-ambulacra with six rows of turbercles at the ambitus, the two 
central of which are complete, and the four lateral incomplete ; tubercles nearly all of the 
same size ; pores uniformly bigeminal throughout. 

Dimensions. — Height one inch ; transverse diameter one inch and seven tenths ; 
mouth-opening six tenths of an inch. 

I)escnj)tion. — This rare Urchin forms the type of a new genus, established by my friend 
M. Cotteau for a similar rare species from the Neocomian of Caussols (Var). The test is 
of moderate size, circular at the ambitus, inflated at the sides, convex on the upper 
surface, and flattened at the base. The arabulacral areas are moderately wide, and retain 
their proportional diameter throughout the area ; they have two rows of marginal 
tubercles of small size, which extend from the peristome to the disc (PI. XXIX a, fig. 1), 
and are very regular both in size and arrangement ; between the base and upper surface two 
other rows occupy the centre, so that this area at the ambitus is furnished with four rows 
of tubercles (PI. XXIX a, fig. 1 g), the two inner ro\vs of which disappear at the lower 
seventh (fig. 1 h) and upper third of the areas (fig. 1 d) ; the tubercles are nearly all of the 
same size ; around the base of the bosses some fine granules are sparsely distributed, 
which form impeifect circlets around them (PI. XXIX a, figs. 1 d, e,f,g, h). None of 
the marginal rows in the specimen is complete, so that the exact number in each series 
cannot be ascertained ; but as thirty can be counted in one incomplete column, six more 
may be fairly estimated as wanting (fig. 1 a, h, c). 

The poriferous zones are moderately wide, and very uniform in diameter throughout, 

1 "Echinides foss. des Pyrenees," p. 16. E.xtrait du ' Congres scientifique de France,' 28' session, 
tenue a Bordeaux, t. iii, pi. ix, 1863. 



FROM THE CHLORITIC MARL. 115 

expanding, however, near the mouth, where an increased number of holes seem ahnost 
completely to encircle the peristome (fig. 1 h) ; throughout the zones the pores are very 
regularly bigeminal, and are grouped into distinct ranges, the small plates forming these 
zones being beautifully dovetailed into each other (figs. 1 d, g, h) ; by this arrangement 
there are from six to seven pairs of holes opposite each ambulacral plate, which gives 
3G X 6 = 216 pairs of holes in each zone. 

The inter-ambulacral areas are rather more than double the width of the ambulacral ; 
the individual plates are long and narrow, being only a little deeper than those of the 
latter ; two rows of tubercles occupy the centre of the plates, and extend very regularly in 
size and disposition from the peristome to the disc ; on the zonal side of this central row 
a second row extends from the peristome over three fourths of the area, and between the 
central row and the median suture there is another row of the same length ; in addition 
to these six rows a few additional tubercles are introduced at the zonal and median sides 
of the widest ambital region of the area. I have shown this chaiacter in figs. 1 (/ and h, 
and the gradual disappearance of the tubercles in the upper part of the area is seen in figs. 
1 a and c, and in its lower part in figs. 1 b and h ; between the tubercles a number of 
small granules are sparsely distributed over the surface of the plates. 

The tubercles in this genus are very uniform in size and structure throughout both 
areas ; the boss rises suddenly from the surface of the plate, without any areolar depres- 
sion ; its summit is very finely crenulated only where it closely embraces the mammillon, 
which is small, prominent, and perforated at the summit ; in the widest part of the 
areas the granules form imperfect circlets around the tubercles, and an increased orna- 
mentation at the ambitus and base ; at the iipper surface they become more sparse in the 
ambulacra (fig. 1 d), and are almost entirely absent in the inter-ambulacra (figs. 1 a, c). 

The mouth-opening is nearly circular, about one third the diameter of the test (fig. b) ; 
the peristome is slightly incised and vmequally divided, the ambulacral being much longer 
than the inter-ambulacral lobes, allo\Aing a wider space for the development of pedal pores 
around the peristome. 

The apical disc is absent, and the upper part of the test is unfortunately broken off, 
so that no indication of the size or form of the disc remains imprinted on the mould. 

Affinitws and Differences. — The only two species of this genus at present known 
are Pedinopsis Meridanensis, Cotteau, from the Neocomian of Aude ; and P. Wiesti, 
Wright, from the Chloritic Marl near Chardstock. These Urchins resemble each other 
very much ; P. Meridanensis (PI. XXIX a, fig. 2^) has a greater number of tubercles ; 
and they are likewise larger and more regulai'ly disposed on the plates ; the poriferous 
zones are wider, and the holes larger than in P. Wiesti. The bigeminal character of the 
zones, the smallness of the tubercles, and the thinness of the shell, are special characters 
by which this Urchin can be readily distinguished from all other congeners. 

1 Copied from M. Cottcau's ' PaMontologie Franfaise,' pi. 112.j, for comparison witli tlie English 
species. 



116 ECHINOCYPHUS 

Locality and Slratiriraphical Position. — Tliis specimen was collected by Mr. Wiest, from 
the Chloritic Marl near Charclstock, Somerset, whei'e it is associated with several species 
of Echinida that are characteristic of the Upper Greensand formation. 

EcHiNocYPHUs, Cotteau, 1860. 

Glyphoctphds (pars), Besor, 1856. 
Cyphosoma (pars), Woodward, 1857. 
EcHiNOCTPHUs, Cotteau, 1860. 

Test small, circular, moderately high, more or less inflated on the upper surface, very 
concave at the base. Poriferous zones straight, and composed of simple pores throughout. 
Ambulacra! and inter-ambulacral tubercles nearly the same size in both areas, bosses 
crenulated, mammillon not perforated. In many specimens the ambulacra have only one 
row of tubercles instead of two, their normal number. 

The inter-ambulacral plates are marked at the base with more or less well-marked 
sutural and hoi'izontal impressions. Peristome moderately large, subcircular, sunk in a 
depression, and provided with slight lobes. Apical disc unknown, opening elongated 
and subpentagonal, as indicated by the impression. 

This genus was established to receive certain species referred by some authors to the 
genus GlyjjJioci/phus, by others to Cyphosoma. These species, according to M. Cotteau, 
are distinguished from Glyphocyphis by their imperforate tubercles, their horizontal sutural 
impressions, and less solid apical disc. Their crenulated and non-perforated tubercles 
bring them into near relation with certain species of Cyphosoma, as C. Delamarrei and 
C. maynificum, var. sulcatum, which show at the base of their inter-ambulacral plates some 
traces of sutural impressions ; but these feeble depressions, however, cannot be compared 
with the deep horizontal grooves that characterize Echinocyphus, and impart to the few 
species composing this group the physiognomy of Glypihocypihus, with which M. Desor 
placed them. 



Echinocyphus difficilis, Ayass. PI. XXII, figs. 1 «, i, 3 a, b, c, d, 4. 

Cyphosoma difficile, Ayass. Catal. Syst. Ectyp., Mus. Neocom., p. 12, 1840. 

— — Agassis et Desor. Catal. rais. des Echinid., Ann. Sc. Nat., 

3e serie, tom. vi, p. 352, 1846. 

— — Bronn. Index Palieontologicus, p. 381, 1848. 
DiADEMA ROTULARE, McCoij. Mesozoic Radiatft, Ann. of Nat. History for 

December, 1848. 

— Maccoyi, Forbes. Catalogue of British Fossils, Morris, 2ud ed., 

p. 76, 1854. 

— rotatum, Forl/es. JMeoioirs of Geological Survey, Decade V, p. 3, 

1856. 



FROM THE GREY CHALK. 117 

Glyphocyphus difficilis, Desor. Synops. des fichinides foss., p. 104, 185". 

Cyphosoma difficile, Woodward (pars). Mem. of Geol. Survey, Appendix 

to Decade V, p. 3, 1858. 
Glyphocyphus difficilis, Dujardin et Hupe. Hist. Nat. des Zooph., Echinid., 

p. 513, 1862. 
EcHiNOCYPHUS difficilis, Cotteau. Pal. Fran9aise, Ter. Cretace, t. vii, p. 708, 

pi. 1174, 1866. 
— EOTATUs, CoMeaw (pars). Ibid., t. vii, p. "11, pi. 1174-/5. 

Test small, subcircular, moderately inflated on the upper surface, flattened at the 
base, concave around the mouth, and rounded at the sides ; poriferous zones narrow, 
straight, and subflexuous at the ambitus ; pairs of pores in a single series ; ambulacral 
areas narrow above, enlarged at the ambitus, with two rows of tubercles, one of which is 
often abortive ; inter-ambulacral areas wide, having two rows of tubercles ; plates pos- 
sessing small, strongly radiated areolae, and divided by deep sutural impressions ; apical 
disc equal to the oral opening, flat, and finely granulated. 

Dimensions. — Transverse diameter eight tenths of an inch ; height four tenths of an inch. 

Description. — This Urchin has long been mistaken for a Diadeiiia, and is catalogued in 
some lists of Upper Greensand fossils as D. rotatmn. Small specimens, measuring from four 
to five lines in diameter, are abundant in the Upper Greensand of Warminster, and may 
readily be distinguished from Diademas by the sutural impressions on their plates, the 
small radiating ribs on many of the large areote, and the irregularity of the two rows of 
ambulacral tubercles, one of which is often abortive. The larger and taller specimens 
agree with the published mould of Professor Agassiz's type specimen of Cyphosoma dijficile, 
to which this Urchin is now referred. 

Almost all the examples I have collected from the Upper Greensand are small and 
well preserved ; the few I have from the Lower Grey Chalk are larger, and show the 
sculpturing of the plates better. The test is subcircular, or slightly pentagonal, mode- 
rately convex on the upper surface, flattened at the base, and rounded at the border. 
The poriferous zones are narrow, straight above and below, and siibundulated at the 
ambitus. The pores are small, and form a single series of pairs throughout from the 
mouth to the disc (fig. 2 d) ; the pairs of pores are separated horizontally by small promi- 
nent ribs, more or less granular, which correspond to the poriferous plates, and are pro- 
longed to the base of the tubercles. The ambulacral areas are narrow, and provided with 
two rows of tubercles ; in some specimens from the Grey Chalk these rows are regular 
and the tubercles of equal size, but in many specimens from the Upper Greensand, 
as in figs. 2 a, b, c, d, one row becomes abortive, and the other only is developed ; 
more than half the specimens that have passed through my hands have been thus 
formed. The inter-ambulacral areas are wide, with two rows of tubercles a little 
larger than those occupying the ambulacra ; in large specimens there are ten or twelve 
tubercles in each row, the number depending on the age of the individual. Between 
the ambitus and peristome the areolas are well developed, and surrounded by 



lis ECHINOCYPHUS 

circles of large sul)- elliptical granules, that are prolonged in a radiated manner towards 
the base of the mammillon (fig. 3 d). The coronal plates at their lower border are 
marked by a horizontal depression, as if the lower half of the plate had been scooped out 
(fig. 2 a) at the expense of a portion of the granular circle. The boss is prominent, 
and its summit is marked with feeble crenulations. The maramillon is always large and 
unperforated. The miliary zone is wide in its upper part, and the surface of the plates is 
covered with a very fine granidation ; at the ambitus it is filled with two or three rows of 
large granules, which diminish below into a single series, and take a zigzag direction 
towards the peristome. 

The small mouth-opening, about one third the diameter of the test, is lodged in a 
concave depression (fig. 2 b). The peristome is circular, and nearly equally lobed, and 
the incisions are slight. 

The apical disc, which is very rarely preserved (PI. XXII, fig. 4), equals the oral 
opening in size, and is flat and finely granulated ; the cordate ocular plates are rather 
large, and perforated close to the ambulacral margin ; the large ovarial plates are per- 
forated, and the madreporiform body occupies the right anterior plate ; the single posterior 
plate is wanting. 

Affinities and Differences. — This species very much resembles Cypliosoma rotatum, Forb., 
of which it proves to be a A'ariety ; the irregularity of the two rows of ambulacral tubercles, 
one of which is often abortive, is not, according to our observations, a persistent character, 
and for this reason we regard E. dijjicilis and E. rotatus as varieties of one form. M. 
Cotteau, however, considers them distinct, and takes as a diagnostic character the single 
row of tubercles in the ambulacral areas, as this difference does not appertain to age, 
seeing that it is found in small as well as in large speciuiens. Echinoci/phus difficilis, 
Ag., may be confounded with Gli/phoci/pJius infermedius, Cott., which has a similar dis- 
position of the ambulacral tubercles, only that they are perforated in Glijphocyplius 
and vmperforated in Echinocyplms. 

Locality and Stratigrapliical Position. — I have several specimens which I collected 
from the hard Grey Lower Chalk near Folkestone, and numerous smaller examples from 
the Upper Greensand near Warminster; from the latter foruiation a very large specimen 
was obtained, now in the cabinet of G. E. Sloper, Esq., Devizes. The late Dr. S. P. 
Woodward states that it measures nine lines in diameter, and four and a half in height ; 
both rous of ambulacral areas are well developed, and the miliary granules form a 
prominent framework to the tubercles. 

In France, M. Cotteau records this species from the Etage Cenomanien of Vellclaire 
(liaute-Saone), and Presagny (Eure), where it is rare. 

History. — First catalogued as Diadcma rolidare, Ag., from Durdle Door, Dorset, by 
Prof. McCoy, in his ' Mesozoic Radiata,' in 1848, and afterwards by Prof. E. Forbes, as 
Diadema rotatum, from the Upper Greensand of Warminster, in the second edition 
of the ' Catalogue of British Fossils.' 



FROM THE GREY CHALK. 1J9 



EcHiNOCTPHUS MESPiLiA, Woodward. PI. XXn, figs. 3 a, h, c, d. 

Cyphosoma MESPILIA, Woodward. App. Decade V, Mem. of the Geol. Survey, 

p. 3, 1856. 

Test small, circular, inflated oi* depressed, convex above and below, with subequal 
apertures ; poriferous zones straight, simple, pairs of pores very ol)liqne ; tubercles nearly 
equal, prominent, imperforate and crenulated ; areolas small, radiated, with elongated 
miliary granules, sutural impressions slight; inter-ambulacra wide, with two rows of 
tubercles, seven to eight in each ; auibulacra narrow, with seven to eight tubercles, alter- 
nate, and irregular. 

Dimensions. — Height three lines ; transverse diameter five lines. 

Description. — This species was discovered by my late friend, Dr. S. P. Woodward, 
who found it in the Lower Hard White Chalk along with Cyphosoma simplex, Forb., and 
Salenia gramdosa, Forb. It is a pretty little Urchin, with inflated sides ; the test is nearly 
convex above and below, the poriferous zones are straight and simple, the unigeminal 
pores are very oblique, the ambulacral areas are narrow, and the tubercles, seven or eight 
in number, are alternate and irregular (fig. 3), one of the rows being partially abortive. 
The inter-ambulacral areas are wide, and have two rows of prominent tubercles, seven to 
eight in each row (fig. 3), which occupy the centre of the plates, and are surrounded by 
small radiated areolae, formed by an oblique arrangement of the elongated granules 
thereon, and imparting an ornamented character to the test. The mouth-opening is more 
than one third of the diameter of the test, the peristome is nearly equally lobed, and the 
incisions are wide and deep. The discal opening is larger than the oral in diameter. 

Affinities and Differences. — This Urchin very much resembes E. difficilis ; it has, 
however, a more inflated test, with stronger radii on the areolae, and larger oral and discal 
apertures. Its author considered it " a very distinct species," and called ray especial 
attention to it. A careful comparison of the accurate figures of both species drawn on 
PI. XXII will enable the student to appreciate the affinities and differences between them 
better than any description, however elaborate. 

Locality and Strati/jraphical Position. — E. mespilia has been collected only from the 
Lower Chalk, in the hard beds of which it has been found, associated with Cypihosoma 
simplex and Salenia granulosa. The only specimens I have seen are in the British 
Museum. 



120 GLYPHOCYPHUS 



Genus — Glyphocyphus, Haime, 1853. 

Arbacia (pars), Agassis, ISSfi. 
EcHiKOPSis (pars), Agassiz, 1&46. 
Hemidiadema, Agassis, 1846. 
Temnopleuea (pars), Sorignet, 18.50. 
GLYniociYPHCs, Jules Haime, 18.53. 

— Besor, 18.56. 

— Cotteau, 1839. 

The Urchins forming this group have a small circular test, more or less inflated above 
and concave below. The poriferous zones are straight, depressed, and composed of uni- 
geminal pores throughout. The primary tubercles of both areas are nearly of the same 
size. The boss, with its crenulated summit, is surrounded by a distinct areola, and sur- 
mounted by a small niammillon minutely perforated at the vertex. The ambulacral and 
inter-ambulacral plates are marked with sutural depressions, which are wider and deeper 
on the plates of the latter areas ; the surface is covered with fine, close-set homogeneous 
granules, nearly uniform in size over the whole test (PI. XXIX b, figs. 1 and 2). The 
apical disc is a small annular structure, solidly united to the test, and forming a narrow, 
sHghtly elongated, oblong ring, composed of five ovarial and five ocular plates, articulated 
alternately together on the same line around the vent aperture or periprocte (fig. 2 b). 
The ovarial plates are the largest ; they have a triangular shape, with tubercles external 
to the annulus, and a large hole at the apex ; the right antero-lateral plate is the largest, 
and supports the niadreporiform body. The rhomboidal ocular plates are wedged in 
alternately on the same line with the ovarials ; and the portion external to the annulus is 
covered with numerous granules. Mouth-opening is small, subcircular, and sunk in a 
slight depression ; peristome decagonal, divided into lobes by feeble incisions. 

The genus G///p/ioc//jj/ais forms among the Diademad^ with crenulated and perforated 
tubercles a very small group, in which the ambulacral and intcr-arabulacral plates are 
marked with angular impressions, and their surface covered with prominent close-set 
granulations. The solidity of the apical disc, and its firm articulation to the coronal 
plates, with the regularity as regards size and arrangement of the tubercles in both 
areas, form an assemblage of characters which readily distinguish the small Urchins of this 
group from their congeners. A considerable difference of opinion has prevailed amongst 
Echinologists regarding the true characters of the forms now comprised in this genus, 
arising, doubtless, from the smallness of the individuals themselves, the imperfect pre- 
servation of most of the specimens, and the destruction of many of the essential structures 
that distinguish them, M. Cotteau, however, had lately at his disposal a fine series of 



FROM THE GREY CHALK. 121 

beautiful and perfect specimens of Glyj)hocyphis radiafus, collected by the late M. Triger 
from the Terrain Cretace of the department of the Sarthe, and from the study of these 
M. Cotteau has been enabled to clear up doubts that had previously existed regarding the 
structure of many of the species. This genus is nearly allied to Echinocyphis, which 
presents a similar facies of lateral impressions on the ambulacral and inter-ambulacral 
plates, but is distinguished from it by having the mammillons of the tubercles perforated, 
whereas in EcMnocyphus they are imperforate. The apical disc is, likewise, solidly united 
to the coronal plates in Gli/phocyphus, but slenderly so in EcMnocyphus. M. Agassiz 
proposed the genus Hemidiadema for Urchins differing from the Diademas in one 
character, that the ambulacral areas possessed only a single row of tubercles, and cited 
as the type of this group Hemidiadema ?7((?os?«;?, Agass., from the Upper Greensand (Etage 
Cenomanien) of Grandpre, Ardennes, a small species having the ambulacral tubercles 
as large and even larger than the inter-ambulacrals ; this Urchin, it now appears, is a true 
Glyphocyphis, with a single row of tubercles in its ambulacral areas — a character which 
is only specific, and not generic, as far as we at present know. 

The genus Echinopsis, Agass., in which certain species of Glyphocyphus have been 
placed, consists, according to its author, of " small, subconical, inflated Urciiins, with the 
ambulacra nearly as large as the_ inter-ambulacra, and both ornamented with tubercles 
perforated but not crenulated. Mouth small, with feeble incisions, differing from the 
Diademas by the absence of crenulations on the tubercles." To this genus was referred 
Echinopsis contexta, Ag., E. latii^ora, Ag., E. depressa, Ag., all of which are forms of 
GIyp)hocypjhus radiafus and Glypticus KonincJcii, Forb. Echinopsis pusilla, Roem., and 
Temnopleurus pulcheUiis, Coquand, must now likewise be added to the list. 



GLYPHOcypHUS RADiATUs, IIoBnin(/haus. PI. XXIX b, figs. 1, 2, a, b, c, d, e. 

t 

EcHiNDS EADIATUS, Homiiiffhaus in Gold/uss. Petref. Germanise, p. 124, tab. xl, 

fig. 13, 182ti. 

— — Agassiz. Prod., Mem. Soc. Nat. des Sc. de Neufchatel, 

t. i, p. 196, 1836. 

— — Desmonlins. Etudes sur lea Echinides, p. 292, No. 55, 

1S37. 
EcpiNOPSis LATIPORA, Agassiz. Catal. Syst. Ectyp. foss., Mus. Neoc, p 9, 1840. 

— CONTEXTA, Agassiz. Ibid. 

— DEPRESSA, Agassiz. Ibid. 

Echinus badiatus, Vujardin. In Lamarck's Anim. sans Vert., 2e e'd., t. iii, 

p. 371, 1840. 
Aebacia radiata, Roemer. Norddeutschen Kreidegebirges, p. 30, 1840. 

Echinopsis pusilla, Roemer. Ibid., pi. vi, fig. 10, 1840. 

Cyphosoma radiatum, Agassiz et Besor. Ann. Sc. Nat., 3e surie, t. vi, p. 352. 

Cat. rais. des Bcbinides, 1846. 

16 



ECHINOPSIS PUSILLA, 


Morris. 


— LATIPORA, 


Pietet. 


CONTEXTA, 


Pictet. 


DEPRESSA, 


Pietet. 


PCSILLA, 


Pictet. 


Cyphosoma badiatum, 


Pietet. 


Glyphocyphus radiatus, 


Desor. 



122 GLYPHOCYPHUS 

EcuiNOPSis LATIPORA, Jgassiz et Desof. Ibid., p. 351, 1 84G. 

— CONTEXTA, Agassiz et Desor. Ibid. 

— DEPRESSA, Agassiz et Besor. Ibid. 

— CONTEXTA, Bronn. Index Palseontologiciis, p. 447, 1818. 

— DEPRESSA, Bronn. Ibid. 

— LATIPORA, Bronn. Ibid. 

— PUSiLL.i, Bronn. Ibid. 

Arbacia RADIATA, Bronti. Ibid., p. 91, 1848. 

TEMNOPLEUKUSPDLCHELLUSjiSor/jrne^. Ours. fossiles du Dep. de I'Eure, p. 31, 1850. 
Glyptious Koninckii, Forbes. la Di.xon's Geology of Sussex, p. 340, tab. xxt, 

fig. 30, 1850. 
EcHiNOPSis PDsiLLA, Forbes. In Dixon, ibid., tab. xxv, fig. 31, 1850. 

— — Giebel. Deutschlaiids Petrefacteu, p. 320, 1852. 
Glyphocyphus pulciiellus, d'Archiac et Jules Haime. Descript. Nummilites de I'liide, 

p. 202, 1854. 
Morris. Catal. of Brit. Fossils, 2nd. ed., p. 78, 1854. 
Tiaite de Paleontol., 2e ed., p. 242, 1846. 
Ibid. 
Ibid. 
Ibid. 
Ibid. 

Synopsis des fichinides fossiles, p. 103, tab. xvii, 
figs. 1—3, 1856. 

— — Cotteau et Triger. Eciiinides du de'p. de la Sartlie, p. 185, 
pi. xxviii, figs. 7 — 12, 1859. 

— — Dujardin et Hupe. Hist. uat. des Echinod., p. 513, 1862. 
Temnopleurus pulchellus, CojMarerf. Geol. et Pal. de la prov. de Constaiitine, p. 294, 

1863. 
GLYPHOCYPnus radiatus, Cotteau. Paleont. Fi-an9., Ter. Cretace', t. vii, p. 535, 

pi. 1127, 1128, 1863. 



Test small, circular, inflated, subglobular, rounded at the border and concave at the 
base ; ambulacra very narrow, with two rows of tubercles, alternate, irregular. Poriferous 
zones narrow, straight ; simple pores in single oblique pairs. Inter-ambulacra with two 
rows of small tubercles, areolae radiated, plates grooved at the lower border ; apical disc 
solid, forming a narrow, elongated, subpentagonal ring, having the genital and ocular 
plates almost of equal length ; oculars finely granulated ; vent large, oblong. 

Dimensions. — Height five twentieths of an inch ; transverse diameter eight twentieths 
of an inch. 

Description. — This small Urchin has been a great puzzle to Palaeontologists, as proved 
by the long Hst of synonyms given above. The test is circular, inflated, and subglobular; 
rounded at the sides, and concave towards the base (figs. 1 a, b). The ambulacral areas 
(fig. 2 e), about half the width of the inter-ambulacral, have two rows of smafl tubercles, which 
form an alternate series on each side of the area ; they are largest at the ambitus, smaller 



FROM THE GREY CHALK. 123 

at the base and upper surface ; they are feel)ly developed throughout, and finely perforated 
at the summit ; the areote are regularly spaced out and placed on the border of the poriferous 
zones, which are straight, slightly depressed, and formed of small round pores, disposed 
in single oblique pairs throughout, from the peristome to the disc ; the pairs of pores 
are separated from each other by a horizontal granular ridge of the test, which is more or 
less apparent in diff'erent s])ecimens ; in some examples one of the rows of tubercles 
becomes abortive ; the surface of the area is filled in with numerous small granules, and the 
ambulacral plates are shghtly marked with impressions on the line of the median suture. 
The inter-ambulacral areas, fig. 2 c/, are double the width of the ambulacral, and provided with 
two rows of tubercles, similar in structure to, but larger in size than, those of the ambulacra; 
the areolae occupy the centre of the plates, and are surrounded with a close-set granulation ; 
two of the granules, elongated in a vertical direction, unite the contiguous areolae, which 
imparts a moniliform character to well-preserved tests of this pretty little Urchin ; the plates 
are marked with impressions more or less deep at the inner and outer angles, and on each 
side of the vertical filament at the lower part of each plate (fig. 1 c, fig. 2 c). 

The mouth-opening is small, situated in a slight depression, and the peristome is 
delicately incised into ten unequal lobes (fig. 2 a). 

The vent is large, sub-elliptical in shape, and contracted behind ; the apical disc 
forms a narrow, elongated, subpentagonal ring, somewhat peculiar in its structure, for 
instead of the small ocular plates being wedged in between the larger genitals, they 
are arranged alternately with them on the same fine, and form a strong ring around the 
elliptical vent ; the genital plates are a little larger than the oculars, and have two small 
tubercles on their surface ; the oculars are covered with a fine granulation, and the 
madreporiform tubei'cle is conspicuous by its spongy surface (fig. 2 h). 

This Urchin varies much in size ; the specimens figured by Goldfuss, Desor, and 
Dixon, with those I possess, are all small. M. Cotteau has given elaborate details of a 
larger specimen found in the Department of the Sarthe, in which the characters of the test 
are admirably exhibited ; they are beautifully figured, both in his fine plates on the Echinides 
of the Sarthe, and likewise in those in the ' Paleontohigie Eran9aise,' some of which I have 
copied in PI. XXIX b, as none of my specimens have the characters so well preserved as 
in the ])erfect fossil test figured by my friend. 

Jffiiiities and Differences. — Gbjpliocyphas radiatus is so rare an Urchin in the English 
Chalk that it is not likely to be mistaken for any other. It is smaller and more globular 
than Ecliinocyphus difficilis, which it most resembles, and has the tubercles perforated, the 
miliary zone wider and more granular, the disc smaller and more solidly united to the 
coronal places than in any Ecliinocyphi. 

From a careful examination of the ample materials at his disposition, M. Cotteau con- 
cludes that the large examples forming the type of the species represent EcJiinopsis 
contexta, Ag., and exhibit natural impressions either deep and angular or linear and 
attenuated. Some specimens, less inflated, and possessing a stronger development of the 



124 ECHINOTHURIA 

vertical filament form E. latipora, Ag., and depressed examples with the median impres- 
sion almost absent are E. depressa, Ag. A careful study of the original types has, liow- 
ever, convinced my learned friend that they are all varieties of one form, and not distinct 
species. 

Locality and StratigrapMcal Position. — This species is found very rarely in the hard 
beds of the Lower Chalk near Lewes, in Sussex, and in the Grey Chalk near Folkestone. 
From tliis stratum my best specimen v^^as collected by Captain Cockburn, R.A., to whose 
kindness and liberality I am indebted for the example. 

The Foreign Localities given by M. Cotteau are Villers-sur-Mer, Bruneval, Saint- 
Jouin, Vaches-Noires, Dives (Calvados) ; Fecamp, le Havre, Rouen (Seine-Inferieure) : 
Gace, La Perriere (Orne) ; Nogent-le-Bernard (Sarthe) ; Saint-Fargeau (Yonne) ; la 
Bedoule, Cassis (Bouches-du-Rhone). In all these localities it is very rare, and occurs 
in the Etage Ccnomanien, in the zone of Scaphites cequalis, which is the equivalent of the 
English Low'Cr Grey Chalk. 

Historj/. — This species was found in the Lower Chalk of Essen and Gehrden, West- 
phalia, and was first figured and described by Goldfuss in his ' Petrefacta Germanise.' 
Since that time it has passed through a series of changes which are most correctly read 
in the long list of synonyms introductory to this article, and to which I commend the 
reader's especial attention. 



Genus — Echinothuria,^ Woodward, 1863. 

" Test globular ?, diameter of compressed specimen four inches, thickness half an inch, 
lantern projecting half an inch ; composed of ten segments or double series of imbricating 
plates, ornamented with obscure miliary granules and small spine-bearing tubercles, a few 
larger than the rest ; inter-ambulacral plates narrow, slightly curved, with the convex edge 
upwards and overlapping ; the alternate plates bearing one large extero-lateral tubercle, 
perforated, and surrounded by a raised ring and smooth areola ; largest plates measuring 
six lines in length, the smallest three lines or less (the longest in second specimen equal- 
hng seven lines) ; ambulacral plates seven lines long, equalling the breadth of the exposed 
portion of eight plates, similar to the former, but curving and imbricating downwards 
towards the dental orifice, and having two small plates, each perforated by a pair of pores, 
intercalated in a notch of the middle of the lower margin; a third pair of pores perfo- 
rating the plate itself a little external to the centre ; primary tubercles few, irregularly 
distributed. 

1 " Etymologists need not trouble themselves about the derivation of this name ; it is intended merely to 
express the dilemma in the writer's mind, arising from imperfect knowledge, but which he believes to have 
no foundation in nature."— ' Geologist,' vol. vi, p. 330. 



FROM THE WHITE CHALK. 125 

" Spines of three kinds ; those adhering to the plates minute and striated ; fragments of 
larger spines (not certainly belonging to the species) striated, annulated, and furnished 
with a prominent collar to the articular end (fig. 4) ; the third kind minute, clavate, and 
truncate, articulated to a slender stalk " (fig. 5). 



EcHiNOTHURiA FLORis, Woodwcml} — PI. XXIX B, figs. 3 — 5. 

EcHiNOTHURiA FLORIS, Woodward. 'Geologist,' vol. vi, pp. 327 — 330, 1863. 

" The fossils represented " in PI. XXIX b " are probably only fragments of the original 
structure, and possibly only the smaller and less essential portions of the whole. Never- 
theless, I have determined to publish some account of them, although at the risk of 
committing an extravagant error, as a last resort towards obtaining more complete ex- 
amples or suggestions for their more correct interpretation. 

" Both specimens have been presented to the British Museum ; one by J. Wickham 
Flower, Esq., of Park Hill, Croydon, the other by the Rev. Norman Glass, of London. 

" The first example was obtained, at least sixteen years ago, from the Upper Chalk of 
Higham, near Rochester, and was submitted to Professor E. Forbes, in whose custody it 
remained for several years. It was originally shown to me in connection with the 
anomalous Cirripede Loricida, then newly discovered by Mr. Wetherell. The resemblance 
between them is certainly curious ; but there is no real relationship. Mr. Flower's fossil 
exhibits distinct traces of the crystalline structure peculiar to petrified Echinodermata, 
and the pairs of pores in the ambulacral plates are equally characteristic of the Echinidse. 
Mr. Darwin also has examined this fossil and rejected it from his province of inquiry. 

" Professor Forbes could not make up his mind to describe the specimen, and ulti- 
mately it was returned to Mr. Flower, with whom it remained until the publication of a 
note on the genus Profo-echinus, by Major Thomas Austin, in the ' Geologist' for 18G0 
(vol. iii, p. 44G), when it was entrusted to me for the purpose of considering whether it 
had any special affinity with this new type, and for description in the same journal. 

" The Proto-ecMniis was obtained from the Carboniferous Limestone of Hook Head, 
Wexford, and is but a fragment of a single ambulacrum, consisting of three series of 
plates at the wider end and two at the other extremity, with apparently a single terminal 

' ' On Echinothuria Jloris, a new and anomalous Echinoderm from the Chalk of Kent.' By S. P. 
Woodward, F.G.S. I have printed tliis paper from the ' Geologist ' entire (altering the references to 
figures), as a contribution to British Echinology by my late esteemed friend. Dr. Woodward took so 
warm an interest in my work, and aiTorded me such valuable assistance, by the loan of specimens for 
fig;uring, that it affords me very great pleasure to acknowledge here his uniform kindness, and connect 
his name with a Monograph to which be contributed important aid. 



126 ECHINOTHURJA 

plate. Each plate is perforated by a pair of pores. It differs from EcJiinofhuria in 
every particular. 

" The question presented to me by Mr. Flower's fossil was, whether to consider it part 
of the envelope of a new kind of Hohfhurla, or whether it might be no more than a fragment 
of the oral disc of some great unknown Echinus. Portions of tlie imbricating scaly 
armour of a Psolus had been met with when examining the fossils of the Boidder Clay 
collected by Mr. J. Richmond, of Rothsay ; but in Psolus, while the greater part of the 
body is clothed with fish-like scales, the ambulacra are only developed on one side, form- 
ing a creepmg disc, the scales of which are small and not imbricated. On the other hand 
the peristome of the largest known Echinite from the Chalk is less than an inch in 
diameter; and the largest recent Sea-urchin in the lAIuseum has an oral disc not more 
than two inches wide, whereas the fossil is a segment of a disc which must have been at 
least four inches across. This objection, on the score of size, was, however, less felt 
because the Cyphosomas and Diademas of the Chalk have larger oral and apical orifices' 
than any other Urchins, and the character of their apical disc was unknown, beiug only 
preserved in a few minute specimens of C. difficile, from Chute Farm. Mo'reover^here 
were indications in the Upper Chalk of a great Diadema, of which nothing more had been 
obtained than scattered plates and fragments of spines. This species Is referred to in 
Decade V of the ' Geological Survey ' (Article " Diadema," Section C, spines tubular, annu- 
lated). Mr. Wetherell obtained a mass of Chalk containing above one hundred fragments 
of spines, which are hollow, striated and aimulated, as in the recent D. caUmaria. "^Froni 
the plates mingled with the spuies we ascertained that the ambulacral pores i)resented 
the usual characters, being arranged in single file, and a little crowded near the peristome; 
but many of the plates presented only their smooth inner surfaces. A smaller mass of 
Chalk, iu Mr. Wiltshire's cabinet, contains similar plates and spines, mingled with a few 
true scales and minute truncated spines like those of Echinoflmria. The Diadema spines 
were erroneously referred by Professor E. Forbes to the genus Micraster (Decade III, pi. 10 
fig. 15 ; bad, for they are not spiral). They are also figm-ed by Dixon, in his ' Geoloo-y 
of Sussex,' and described by Forbes as - spines of a Cidaris.'' Diademas possessing spints 
of this character are known to occur in the Upper Cretaceous strata of France; and 
Dr. Wright has lately obtained a small specimen from the Chloritic Marls of Dorsetshire. 
In these the apical disc is quite small. 

" A more serious difficulty, in comparing Mr. Flower's fossil with the oral disc of any 
Echinite, was presented by the arrangement of the plates ; in the recent Echinidge .... 
they are all directed towards the dental orifice, but here the alternate series take opposite 
' dips,' the ambulacral plates overlapping one way and the others in a contrary direction. 

"Last year, while I was still hesitating about the publication of Mr. Flower's fossil a 
second specimen was obtained from Charlton, in Kent, by the Rev. N. Glass, wlio lias 

cleared it from the matrix with great skill and patience At first sight this' specimen 

would seem to solve the problem, by supplying the peristome and lantern of the same 



FROM THE WHITE CHALK. 127 

great Cyphosoma or Biadema, of which Mr. Flower's specimen might be the apex or 
periproct. But a closer examination confirms the objections ab-eady stated, and gives 
increasing probabihty to the other conjecture (if, indeed, it does not compel us to adopt 
it), however difficult it may be to realise the notion of an Echinite having no proper 
' test,' and clothed entirely with imbricating scales like those of the peristome of Cidaris. 

"In Mr. Flower's specimen the imperforate plates imbricate towards the centre (or apex), 
where the smaller ends of the several series converge. In Mr. Glass's specimen they slope 
away from the centre (or mouth), that is, also towards the apex. The perforated or ambulacral 
plates, which overlap one another outwardly {i. e. downwards) in specimen, fig. 3 a, are seen 
sloping towards the dental cone and reclining upon it. The portion of an ambulacrum, fig. 
5 a, consists of four plates, diminishing in size from c to a, in a line not accurately directed 
towards the centre. This portion exhibits the interior surface of the plates, known by their 
curved surfaces, destitute of ornamental granules ; it is not, however, the oral end of one of 
the segments turned over, a thing scarcely possible to happen, for in that case the dip of 
the plates would be reversed ; but it must be the opposite (or apical) extremity of a series 
folded back upon its origin, and exposed to view by the damage which the surface of the 
specimen has sustained. From this circumstance it seems probable that the whole fossil, 
when complete, was not elongated, nor even spherical, but somewhat depressed in a ver- 
tical direction, though doubtless admitting of a moderate amount of flexure. At the last 
hour, after making the drawing, I ventured to clear away the chalk from the side of Mr. 
Glass's fossil, near where an ambulacral segment is seen to curve as if it might be con- 
tinued round to the other surface. This attempt was successful, for the ambulacrum 
and also the adjacent inter-ambulacral segment were found continuous, though crowded 
and displaced at the turning, falling again into regular order, and diminishing in size, 
though not so nearly complete as in Mr. Flower's example. 

" After this apparently conclusive demonstration, it appears desirable to give a name to 
the fossil, and to attempt a short description, although its rank and affinities are to us 
still matter of conjecture. At present it is one of those anomalous organizations which 
Milne-Edwards compares to solitary stars, belonging to no constellation in particular. 
The disciples of Von Baer may regard it as a ' generalised form' of Echinoderm, coming, 
however, rather late in the geological day. The publication of it should be acceptable 
to those who base their hopes on the ' imperfection of the geological record,' as it seems 
to indicate the former existence of a family or tribe of creatures whose full history must 
ever remain unknown." 

Locality and Stratiyrajjhical Position. — Collected from the Upper Chalk of Higham, 
near Rochester. The fine specimens in the Rev. T. Wiltshire's cabinet were obtained 
from the Upper Chalk at Gravesend and Charlton. 



128 CYPHOSOMA 



Genus — Cyphosoma, Agassiz, 1840. 

Cyphosoma, Agassiz, 1840. 
Phymosoma, Haime, 1853. 
— Desor, 1858. 

Cyphosoma, Cotteau, 1863. 

Test moderate in size, circular or subpentagonal, slightly inflated at the sides. 
Poriferous zones well developed and undulated, composed of simple pores that in 
general are unigeminal throughout, and sometimes are bigeminal on the upper surface, 
and crowded a little together around the peristome. The poriferous plates are un- 
equal and irregular in their mode of arrangement. The primary tubercles are nearly 
equal in size in both areas, the areolae are well developed, and sometimes marked with 
radiated striations ; the bosses are prominent, and have their summits sharply crenu- 
lated ; the mammillon is large, prominent, and imperforate, and the general facies of the 
test shows a regular, and uniform development of all its several elements. The mouth- 
opening is large, the peristome slightly incised, and the oral lobes nearly equal. The 
discal opening is large and pentagonal, one angle of which extended far into the single 
inter-ambulacrum ; the elements of the disc were feebly united, as they are absent in all 
the specimens that have hitherto been collected. 

The spines are long, solid, subcylindrical, aciculate, or spatuliform ; sometimes they 
are straight and lanceolate, or bent, ramiform, or spoon-shaped ; all these varieties are 
figured in Pis. XXIV and XXVI. The stem is smooth and marked with fine longi- 
tudinal striae, the milled ring is prominent, the head distinct, and the rim of the aceta- 
bulum crenulated. 

The genus Cyphosoma is distinguished from all others by its prominent tubercles 
with crenulated bosses, and imperforate mammillons ; in the structure of these it resembles 
lEicMnocyphus and Tenmopleurus, but is readily distinguished from these by the absence of 
the angular and sutural impressions which impart so mai'ked a character to their tests. 

M. Desor has separated into the genus Coptosonia all those Cyphosomata from the 
Nummulitic formation (Tertiary) with much undulated poriferous zones, tubercles with 
very large mammillons, and having the plate-sutures of the areas deeply incised ; thus 
leaving the typical Cyphosomata as true Cretaceous fossils, which first appear in the 
Neocomian beds, and attain their maximum development in the upper stage of the 
White Chalk. 

The Cretaceous rocks of Prance are very rich in species of Cyphosoma, of which a 
very small proportion have hitherto been found in the British islands. 



FROM THE LOWER CHALK. 



129 



A. — Species from the Lower Chalk. 
Cyphosoma granulosum, Goldfuss, sp., 1826. PI. XXHL figs. 2 a, b, c, d. 



CiDARITES GRANULOSUS, 
DiADEMA GRANULOSUM, 



Echinus Milleri, 

Echinus granulosus, 



Goldfuss. Petrefact. Germanise, pi. xl, fig. 7, p. 122, 1826. 
Agassis. Prod., Mem. Soc. des Sc. Nat. de Neufchatel, t. i, 

p. 189, 1836. 
Besmoulins (pars). Etudes sur les Echinides, p. 294, 

No. 68, 1837. 
Bujardin. In Lamarck's Anim. sans Vertebres, 2e ed., 
t. iii, p. 372, 1840. 
CiDABiTES GRANULOSUM, Geinitz. Charakt. der Schict. und Petref., p. 90, 1842. 
DiAPEMA — Moms (pars). Catalogue of British Fossils, p. 51, 1843. 

Cyphosoma — Beuss. Verstein. der Bohm. Kreideform., p. 58, 1846. 

— Milleri, Agassi: et Desor (pars). Catalogue rais. des Echinid., 

p. 351, 1848. 

— — Bronn. Index Palaeontologicus, p. 381, 1848. 

— — B'Orbigny. Prod. Pal. strat., t. ii, p. 273, Et. 22, 1850. 

— — Bronn. Lethsea Geognost., Kreide-gebirges,pl.xxix, p. 186, 

1851. 

— KoNiGi, Forbes. In Morris's Catalogue of British Fossils, 2nd ed., 

p. 75, 1854. 
Phymosoma GRANULOSUM, Besor. Synops. des Echinid. foss., p. 87, 1856. 
Cyphosoma — Woodward. Mem. Geol. Surv., Dec. V, p. 1, 1857. 

Phymosoma — HupL Hist. Nat. Echinod., p. 508, 1862. 

Cyphosoma — Cotteau. Pal. rran9aise, Ter. Cretac^, t. vii, p. 685, 

pi. 1169, IS65. 

Test large, circular, depressed, convex on the upper surface, inflated at the sides, and 
flattened below ; poriferous zones wide and straight in the upper third, narrow and undu- 
lated at the ambitus and base ; pores largely bigeminal in the wide upper third, and 
unigeminal in the rest of the zones ; ambulacra narrow above, wide below, with two rows 
of large tubercles, twelve in each ; inter-ambulacra with two rows of primary tubercles in 
tlie middle of the area, secondary tubercles wanting in young specimens, and only slightly 
developed in the largest tests ; miliary zone wide, depressed, and naked above, narrow 
and granular below ; mouth-opening small and circular ; peristome with shallow entailles ; 
discal opening large, and widely pentagonal. 

Dimensions. — Height eight tenths of an inch ; transverse diameter one inch and eight 
tenths. 

Description. — This Urchin resembles C. Koni^i in so many points of structure, the 
absence or rudimentary condition of the secondary tubercles excepted, that it may pro- 
bably be only a variety of that species. It has, however, been treated by different sys- 

17 



130 CYPHOSOMA 

tematic authors as specifically distinct ; and in deference to their opinion, rather than in 
accordance with my own convictions, I have devoted this article to its description. 

The test large and circular, inflated at the ambitus, convex above, and flat below 
(PI. XXIII, figs. 2 a, h, c). 

The ambulacral areas are enlarged at the ambitus, moderately wide at the base, and 
very narrow in the upper part ; by reason of the increased development of the poriferous 
zones in this region, from the ambitus to the peristome, the tubercles are as large as 
those in the inter-ambulacra, but in the upper third of the area they diminish rapidly 
in size, and on the four or five coronal plates they are quite rudimentary (PI. XXIII, 
fig. 2 a). The pores are arranged in oblique pairs, and are bigeminal from the ambitus 
to the summit (PI. XXIII, fig. 2 c,d), and unigeminal from the ambitus to the peristome, 
the zones forming a series of crescents around the areolae of the ambulacral tubercles. 

The inter-ambulacral areas have two rows of primary tubercles, twelve to thirteen in 
each row, which vary gradually in size from the ambitus to both apertures ; they are sur- 
rounded by well-developed areolae, confluent at the upper and lower borders, and surrounded 
by granules at the sides. The secondary tubercles are irregular, very small, and limited 
to the under surface (fig. 2 6). On one or two plates above the ambitus there are only 
one or two solitary tubercles, which are, however, inconstant in different specimens (fig. 2 d). 
The miHary zone is narrow and granular at the ambitus, and wide, depressed, and naked 
on the upper surface ; the granules are unequal, of different sizes, and placed in semicii'- 
cular groups around the lateral parts of the areolae. Many of the granules are large and 
mammillated, and are nearly as large as the row of secondary tubercles, the small granules 
being compactly fitted in between them. The coronal plates are marked by slight sutural 
impressions, which become more apparent in consequence of the nudity of the depressed 
upper surface of the areas. 

The discal opening is very large, pentagonal, and angular ; and the single posterior 
ovarial plate is projected far into the area (fig. 2 a). The mouth-opening is moderate in 
diameter (fig. 2 b) ; the peristome is circular, and divided into ten unequal lobes by shght 
incisions with reflexed borders. 

Jffinities and Differences. — This species differs from the typical forms of Cyphomma 
Koniffi in the absence of a regular series of secondary tubercles above the ambitus ; but 
in the general character of the test and in most of its details it has close affinities with 
that species. Whether the spines of this Urchin exhibit any difference from those attached 
to the typical form of C. Konitji (PI. XXIV, fig. 1) remains to be determined by those who 
may be fortunate enough to discover a specimen with the spines adherent to the test. 

Locality and StratigrapUcal Position. — This Urchin is found in the Lower Chalk of 
Kent and Sussex. The specimen figured in PI. XXIII, belonging to the British Museum, 
was collected near Lewes. 

Foreign Localities. — Houguemarre(Eure),Orglande(Manche), from the Etage Senonien, 
where it is rare (M. Cotteau) ; the type of Goldfuss's figure was collected from the Chalk 
of Westphalia. 



FROM THE WHITE CHALK. 



131 



B. — Species from the Upper Chalk. 

Cyphosoma Konigi, MantelL PI. XXIII, figs. 1,2; PI. XXIV, figs. 1—7; PL 
XXV, fig. 3; PI. XXVI, fig. 1. 



ECHINITE. 
CiDAEIS KoNIGr, 

Echinus Milleri, 

cldarites variolaris, 

Echinus Konigi, 
ClDARITES Konigi, 
Echinus Konigi, 

MlLLEEI, 



DiADEMA Konigi, 
Cyphosoma Milleri, 
diadema granulosum, 
Cyphosoma Milleri, 

— ornatissimum, 

— Milleri, 

— MAGNinCUM, 

DiADEMA Konigi, 
Cyphosoma Milleri, 

— ornatissimum, 

— Milleri, 

— variolabis. 
Echinus Konigi, 
Cyphosoma Konigi, 

ornatissimum, 

Phymosoma Konigii, 
Cyphosoma Konigi, 

ornatissimum, 



Parkinson. Organic Remains, vol. iii, pi. i, fig. 10, 1811. 

MantelL Geology of Susse.x, p. 180, 1822. 

Besmarest. Oursins fossiles. Diet. So. Nat., t. xx.xvii, 

p. 101, 1825. 
Goldfuss. Petref. Germaniee, p. 123, pi. xl, figs. 9 a, b, 

1826. 
Fleming. British Animals, p. 479, 1828. 
Brongniart. Tableau des Terrains, p. 405, 1829. 
Woodward. Synopt. Tab. of Brit. Organ. Rem., p. 6,1830. 
Be Blainville. Zoophytes, Die. Sc. Nat., t. Ix, p. 210, 1830. 
De Blainville. Ibid. 
Agassiz. Prod., Mem. Soc. Sc. Nat. de Neufchatel, t. i, 

p. 190, 1836. 
Desmoulins. fitudes sur les Echinides foss., p. 294, 

No. 68, 1837. 
Besmoulins (pars). Ibid., p. 312, No. 10, 1837. 
Agassiz. Catal. Syst. Ectyp., p. 11, 1840. 
Morris. Catalogue of British Fossils, p. 51, 1843. 
Agassiz et Besor (pars). Catal. rais. des fichinides, 

p. 351, 1846. 
Agassiz et Desor. Ibid., p. 352, 1846. 
Graves. EssaiTopogr. Ge'ognost. Dep. I'Oise, p. 688, 1847. 
Graves. Ibid. 

Bronn. Index Paleeontologicus, p. 418, 1848. 
Bronn (pars). Ibid., p. 381, I84S. 
B'Orbigny. Prodrom. de Pal strat., t. ii, p. 273, 1850. 
B'Orbigny. Ibid., t. ii, p. 273, 1850. 
Forbes. In Dixon's Geol. of Sussex, pi. xxv, figs. 17, 

26, 27, 1850. 
Forbes. Ibid., pi. xxv, fig. 29, 1850. 
B^Archiac. Hist. desProgr. de la Geol., t. iv, p. 20, 1851. 
Forbes. Morris, British Fossils, 2nd ed., p. 75, 1851. 
Forbes. Ibid. 

Besor. Synopsis des Echinides fossiles, p. 86, 1856. 
Pictet. Traite de Pal6ontologie, 2e ed., t. iii, p. 243, 

1857. 
Pictet. Ibid. 



132 • CYPHOSOMA. 

Cyphosoma Konigi, Woodward. Mem. Geol. Surv., Decade V, Appendix, 

1857. 
Phymosoma — Dujardin et Hupe. Hist. Nat. des Zooph., p. 508, 1862. 

Cyphosoma — Woodward. " On Konig's Sea-urchin," Geologist, vol. v, 

p. 41, 1862. 
— — Cotteau. Pale'ontologie Fran9aise, t. vii, p. 678, pi. 1167, 

1168, 1863. 

Test large, subcircular, depressed, convex on the upper surface, inflated at the sides, 
almost flat on the under surface ; poriferous zones wide and straight in the itpper third, 
narrow and imdulated at the ambitus and base ; pores bigeminal in the upper thuxl, uni- 
geminal in the lower two thirds of the zone ; ambulacra narrow above, wider below, with 
two rows of large tubercles, tAvelve in each ; iuter-arabulacra with two regular rows 
of primary tubercles in the middle, and two rows of secondary tubercles, irregular in size 
and distribution, on the zonal sides of the area ; miliary zone wide, naked, and depressed 
above, narrow and granular below ; mouth-opening small, peristome circular, lobes nearly 
equal ; discal opening large, pentagonal ; spines long, subcylindrical ; upper third of 
the stem aciculate, spatulate, straight or bent ; lower third sculptured with fine longitu- 
dinal lines. 

Dimensions. — Height seven tenths of an inch ; transverse diameter two inches. 

Description. — This is one of the largest, most beautiful, and typical of our British 
Cyphosoma; it was well figured by Parkinson, 1811, in his 'Organic Remains,' as "an 
Echinite from Kent with its spine ;" he gave no description of the specimen, and it was 
reserved for Dr. Mantell, 1823, to give it a specific place among our Cretaceous 
Urchins. 

The long list of synonyms prefixed to this article exhibits the historical phases through 
which it has passed, and the numerous admirable and accurate di-awings with which our 
excellent friend Mr. C. R. Bone has enriched our Monograph will make the determination 
of Cyphosoma Konigi a matter of ease and certainty to all future observers. 

The specimen figured PI. XXIII, figs. 1 a — g, belongs to the British Museum. The 
large test is subcircidar, slightly convex above, inflated at the sides, and flattened below 
(fig. 1 c) ; the sm-face is highly ornamented, the tubercles are nearly all of the same size 
and regular in their disposition, and the granules are large and conspicuous at the 
base. 

The ambulacral areas are narrow above, wide at the ambitus, and contracted at the 
base; they possess two rows of tubercles, 12 or 13 in each row; those at the ambitus 
are very large, and nearly equal in size the inter-ambulacral tubercles ; on the upper third 
of the area they diminish rapidly in magnitude, and from the ambitus to the peristome 
are much larger. 

At the ambitus the areolae are wide and confluent, but on the upper surface they are 
narrow and separated only by a line of granules ; the zone which divides the two series is 



FROM THE WHITE CHALK. 133 

contracted, and provided with two rows of granules closely set together, unequal in size 
some of them being mammillated at the angles of the plates. 

The poriferous zones are narrow and undulated at the base and ambitus, and wide and 
straight at the upper surface ; the pores are small, and unigeminal from the peristome to 
the ambitus (fig. 1 e), and distinctly bigeminal on more than the upper third of the 
zones (fig. 1 d) ; near the peristome the pairs are doubled (fig. 1 g). 

The inter-ambulacral areas are about one third wider than the ambulacral, and furnished 
with primary and secondary tubercles ; the primary series consists of two rows, twelve in 
each, occupying the centre of the plates ; the tubercles are smaller on the upper than on 
the lower third of the area ; the secondary tubercles are large and unequal in size ; they 
form a series between the poriferous zones and primary tubercles, some of which they 
resemble in magnitude, especially those extending from the ambitus to the coronal plates ; 
between the ambitus and peristome they are much smaller, and in many specimens are 
not more developed than large granules on mammillated eminences. 

The miliary zone is very wide, naked, and depressed at the upper surface, 
becoming gradually narrower at the ambitus, and much contracted at the base; the granules, 
unequal in size, are fine, abundant, set closely together, and arranged in semicircles 
around the primary and secondary tubercles ; some of the granules, much larger than the 
others, are set on mammillated eminences, and may easily be mistaken for the small 
secondary tubercles placed near them ; this mnigling together of small tubercles and large 
mammillated granules imparts a highly ornamented character to the infra- marginal region 
of this species. 

Discal opening large, pentagonal, and subangular, the elements wanting in all the 
specimens hitherto found. Mouth-opening small, circular, the peristome feebly incised, 
the border reflected, the entailles having the border elevated and opening upwards. , 

The spines exhibit some remarkable variations from the typical form of structure. 
Some of the most curious of these I have figured in Pis. XXIV and XXVI. The 
typical spines, as seen in those in situ in the specimen belonging the British Museum 
(Pi. XXIV, fig. a), are elongated, subcylindrical, and sometimes aciculate at the summit 
(fig. 1 d, and fig. 3 ci), or spatuliforra with carinae, as PI. XXIV, fig. 1 c, or spoon- 
shaped, as PI. XXVI, figs. 1 a, b, the lower part or coUerette being long and distinct, 
and covered with fine longitudinal lines (PI. XXIV, fig. 3 b), much stronger than those 
observed on the stem ; the head is well developed, the milled ring very prominent, flat, 
and deeply striated, and the rim of the acetabulum finely crenulated (PI. XXVI, figs. 1 
a, c, figs. 2, 4, 6), with other varieties of spines figured in this plate. 

The test of this Urchin presents many variations of form from the typical shape seen 
in the specimen figured in PI. XXIII, fig. 1 a, h, and considered to be its normal form. 
In PI. XXIV, fig. 7, I have figured a remarkable monstrosity of this species from 
the British Museum Collection ; it is inversely conical, like Pseudodiadema tumidmn ; 
measures three quarters of an inch in height, and is one inch and one third in diameter 



134 CYPHOSOMA 

above, contracting below down to the oral opening, which, at first sight, appears to be the 
summit of the test. In PL XXII, figs. 5 a, h, c, I have given drawings of a young test 
from the National Collection. 

Affinities and Differences. — This species forms one of the most typical forms of the 
genus Cyphosoma, well characterised by its large size, round and inflated at the 
ambitus, highly ornamented at the base, and having the poriferous pores distinctly 
bigeminal in all the upper part of the zones ; the secondary tubercles are large above the 
ambitus and small at the base ; the spines are strong, elongated, and furnished with a 
striated collar, having the summit sometimes flattened and carinatedj or expanded and 
spatulate, as seen in the different figm^es. 

The nearest affinities of C. Konigi are with C. granulosum, from which it differs in 
having large secondary tubercles above the ambitus and a more ornamented test at the 
base. In size and height, and in the disposition of its tubercles on the upper surface, as 
well as in the bigeminal arrangement of the pores in the upper part of the zones, it much 
resembles C. magnificmn, Agass., from the Etage Senonien inferienre of the south-west 
of France. 

Locality and Stratigraphical Position. — C. Konigi is found in fine preservation in the 
Upper Chalk of Kent, Sussex, Norfolk, Wiltshire, and Yorkshire. In France it is col- 
lected in the Etage Senonian at Thuison (Somme) ; Tartigny (Oise) ; Vernonnet, La 
Villette, Hougouemarre (Eure) ; where it is rare. It is likewise found at Riigen, and 
Csesfeld, near Dusseldorf. 



Cyphosoma corollare, Klein. PI. XXVI, figs. 7, 8, 9, 10. 

EcHiNiTES OEBICULATUS, Xwier. Ilist. Animal. Anglise, p. 220, pl.vii, fig. 19, 1678. 
CiDARTS coKOLLARis, Klein. Natur. Dispos. Echinoderm., pi. viii, fig. c, p. 20, 

1734. 

— — Baier. Oryctographia Norica, p. 70, pi. iii, fig. 36, 1759. 

— — Leske. Klein, Nat. Dispos. Echinoderm., p. 138, pi. viii, 

fig. c, 1778. 

— coRONAiiis, Gmelin. Linne's System. Natur., p. 3177, 1788. 
Echinus saxatilis, Parkinson. Organic Remains, pi. iii, fig. 1, 1811. 
CiDARis COKOLLARIS, Parkinson. Ibid., pi. i, fig. 7, 1811. 

— SAXATILIS, Mantell. Geology of Sussex, p. ISO, 1822. 

— coROLLARis, Mantell. Ibid., p. 181, 1822. 

EcHiNDS SAXATILIS, Fleming. History of British Animals, p. 479, 1828. 

— — Brongniart. Tableau des Terrains, p. 40.5, 1829. 

— — JT'oodwarJ. Synop. Table of Brit. Org. Remains, p. 6, 1830. 

— — I)e Blainville. Zoophytes, Diet, des Sc. Nat., t. Is, p. 210, 

1830. 
CiDARis COROLLARIS, Agassiz. Prodrome des Radiaires, p. 188, 1836. 
Echinus coeollaris, Besmoulins. Etudes sur les Echinides, p. 298, 1837. 



FROM THE UPPER CHALK. 135 

CiDARis cOEOLLAKis, Morris. Catalogue of British Fossils, p. 49, 1843. 

— SAXATiLis, Morris. Ibid., p. 50, 1843. 

CypHOSOMA COKOLLAKE, Agassiz et Desor. Catal. Rais. des Echinides, p. 351, 1846. 
CiDARis coEOLLARis, Bronn. Index Palseontologicus, p. 298, 1848. 

— SAXATILIS, Bronn. Ibid., p. 300, 1848. 

Cyphosoma corollare, TfOrUgny. Prodrome, t. ii, p. 273, Et. 22, 1850. 

— — Forbes. In Dixon's Geol. of Sussex, p. 340, 1850. 

— — Forbes. In Morris's Catalogue of Brit. Foss., p. 75, 1850. 
Phymosoma — Desor. Synop. des Echinides fossiles, p. 88, 1856. 
Cyphosoma saxatile, Desor. Ibid., p. 87, 1856. 

— COROLLARE, Pictet. Paleontologie, 2e ed., t. iii, p. 243, 1857. 

— — Woodward. Mem. Geol. Surv., Decade V, p. 2, 1858. 

— — Leymerie et Raidin. Ge'ol. du Depart, de I'Yonne, p. 621, 

1858. 
Phymosoma saxatile, Diijardin et Hupe. Hist, des Echinoderm., p. 508, 1862. 

— COROLLARE, Dvjardin et Hupe. Ibid. 
Cyphosoma perfectlm, Cotteau et Triger. Echinides de la Sartlie, p. 261, pi. xlii, 

figs. 13—16, 1860. 

— — Cotteau. Echinides foss. des Pyrenees, p. 24, 1863. 

— COROLLARE, Cotteau. Pal. Fran^aise, t. vii, p. 669, pi. 1165, 1864. 

Test small, circular, depressed ; ambulacra wide, two rows of tubercles, nine to ten in 
each, gradually diminishing in size towards the poles ; inter-ambulacra moderate, with two 
rows of tubercles, nine in each, four ambital, large ; areolae defined by rows of granules ; 
miliary zone moderate, granular below, becoming smooth above ; poriferous zones narrow, 
undulated, pores unigeminal, and crowded near the summit ; base concave ; oral opening 
small, one third of an inch in diameter ; discal opening large, pentagonal, half an inch 
in diameter ; spines long, slender, spatulate, one fom'th longer than the diameter of the 
test. 

Dimensions. — Transverse diameter one inch ; height one third of an inch ; in general 
the specimens are not so large. 

Description. — This is one of our most common Cyphosomuta. In certain localities it is 
a small, circular Urchin, rarely exceeding an inch in diameter and about three or four 
lines in height ; it is convex and depressed above, and flat or subconcave below ; the areas 
are nearly equal in width, the tubercles very much alike in form and size, the areolae are 
encircled with granules, and the structure of the different divisions of the test is very 
uniform throughout. 

The ambulacral areas (PI. XXVI, fig. 10), contracted above by the poriferous zones, 
have two rows of primary tubercles supported on large bosses, and arranged in alternate 
series on each side of the area ; in adult specimens there are nine or ten tubercles in a 
row ; the areolae are wide, and a single row of graimles (rarely double) separates them 
from each other. 

The poriferous zones are narrow, and much undulated at the ambitus and infra-mar- 



136 CYPHOSOMA 

ginal region ; tlie small pores are arranged in oblique pairs at the sides, and at the upper 
surface become bigeminal; fig. 10 shows an ambulacral area with its poriferous 
zones magnified six diameters ; fig. 7 h exhibits the upper part of the area magnified six 
times, with the bigeminal arrangement of the pores in the upper part of the zones. 

The inter-ambulacral areas are furnished with two rows of tubercles nearly identical 
with those of the ambidacral ; they are, however, a little larger than the latter in the upper 
surface, and are surrounded by areolae that are placed wider apart. The secondary 
tubercles are very small and unequal in size; they form a series near the zones, one mam- 
millated tubercle rising in each plate from the midst of numerous granules. They are 
most apparent at the lower surface and the ambitus, and are rare on the upper surface. 

The miliary zone is wide, naked, and depressed in the upper surface, forming at the 
ambitus and lower surface a zigzag line, Avhich defines the contour of the plates. The 
granules are large, and those surrounding the primary tubercles at the ambitus send pro- 
longations into the areolae, which impart a radiated character to the structure of these 
parts. The intermediate granules are more or less abundant, and form circles or semi- 
circles around the areolae. The small mouth-opening is lodged in a concave depression 
in the base. The peristome is circular, and divided by feeble incisions, the lobes of 
which are nearly equal. The apical disc is absent. The opening is large, pentagonal, 
and angular, and in our large specimen is about five lines in diameter. 

The spines are long, slender, and spatulate, one fourth longer than the diameter of the 
test, to which they are sometimes found adherent and in situ. 

Affinities and Differences. — C. corollare is readily recognised by its moderate size, 
depressed circular test, sometimes subpentagonal ; the pores are unigeminal on the sides 
and bigeminal on the upper surface, with small secondary tubercles at the base near to the 
zones ; the miliary zone is nude and depressed near the summit ; the mouth-opening is small, 
and lodged in a concave depression. By these characters it may be distinguished from 
C. tiara and young examples of C. yranidosum, both of which it resembles much. 

Locality and Stratiyraphical Position. — This Urchin is very common in the upper 
flinty Chalk of Brighton, Gravesend, and Woolwich. In France M. Cotteau enumerates 
the following localities in which it is rarely found in the Etage Senonien : — Senneville, 
Saint-Pierre en Port (Craie superieure, M. Hebert) ; Seine Inferiem'e, La Herelle (Oise) ; 
Pinterville (Eure) ; Villeneuve-sur-Yonne (Yonne) ; Meudon (Seine-et-Oise) ; Sarlat 
(Dordogne) ; Tercis (Landes). 

History. — The history of this species, one of the oldest Cyphosomas, is very difficult 
to trace, as our table of synonyms has already exposed. Lister and Klein have both 
figured it, and Parkinson has given a very good figure of it under the name of Echinites 
saxatilis in his 'Organic Remains.' Klein's name, however, has the priority, and 
therefore is retained. 



THE 



PALiEONTOGRAPHICAL SOCIETY. 



INSTITUTED MDCCCXLVII. 



VOLUME FOR 1870. 



LONDON: 

KDOCOLXXI. 



MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODBRMATA 



THE CRETACEOUS FORMATIONS. 




THOMAS WRIGHT, M.D., F.R.S. Edin., F.G.S. ^ '"" ^ 

CORKESVONDING MEMBER OF THE KOYAL SOCIETY OF SCIENCES OF LIEGE, THE SOCTETV OF 

NATURAL SCIENCES OP NEUFCIIATEL, AND SENIOR SURGEON TO 

THE CHELTENHAM HOSPITAL. 



VOLUME FIRST. 

PART FOURTH. 
ON THE DIADEMADYE AND SALENIHi^.. 

Pages 137—160 ; Plates XXX— XXXIX. 



LONDON: 

PRINTED FOR THE PAL^ONTOGRAPHICAL SOCIETY. 

1871. 



PBINTED BY 
J. E. ADLAED, BAETHOLOMEW CLOSE. 



FROM THE UPPER CHALK. 137 



Cyphosoma MAGNiFicuM, Affossiz, 1840. PI. XXV, figs. 1, 2 a, h, c, d, e. 

Ctphosoma MAGNii'icUM, Affossiz. Catal. Syst. Ectvp., p. 11, 1840. 

— SULCATUM, Agassiz et Desor. Catal. raison. des Echinides, p. 351, 

18-16. 

— MAGNIFICUM, Bfotin. Index Palaeontol., p. 38 1 , 1 848. 
Phtmosoma — Desor. Synops. des Echinides fo8s., p. 88, 1856. 

— SULCATUM, Desor. Ibid., p. 90, 1856. 

Ctphosoma MiDDELTONi, Woodward. Mem. Geol. Siirv., Decade V, App., p. 4, 1856. 

— SULCATUM, Pictet. Traite de Paleontol., 2eed., t. iv, p. 243, 1857. 

— — Cotteau et Triger. Echinides de la Sarthe, pi. 44, fig. 9, 

1860. 
PiiYMOSOMA — Coquand. Synops. des Foss., Bull. Soc. Ge'ol. de France, 

t. xvi, p. 992, 1860. 
Phtmosoma — Dujardin et Hiipe. Hist. Nat. Zooph., p. 508, 1862. 

Ctphosoma — Bourgeois. Especes Ter. Cretaces, Bull. Soc. Geol. France, 

deux, ser., t. xix, p. 674, 1862. 

— MAGNIFICUM, Cotteau. Echinides foss. des Pyrenees, p. 25, 1863. 

— — Cotteau. Paleontologie Erancaise ; Ter. Cretace, t. vii, p. 

635, pis. 1155-56-57, 1865. 

Test circular, elevated, sides tumid, base concave ; poriferous zones narrow, undulated, 
pores unigeminal ; primary tubercles of both areas large at the base and ambitus, and 
small on the upper surface ; areolae large and confluent at ambitus and base^ very small 
above; upper third of inter-ambulacra bordered with a row of small secondary tubercles; 
miliary zone wide, sulcated, and nude above ; mouth-opening small, peristome equal- 
lobed; discal opening very large, pentagonal, angular, and elongated. 

Dimensions. — a. Figured specimen, latitude ten lines ; altitude six lines. 

B. Specimen in my cabinet, latitude one inch ; altitude half an inch ; discal opening 
(antero-posterior diameter) six tenths of an inch. 

Bescripfion. — This very rare British Cyphosoma was obtained by J. Middleton, Esq., 
from the Upper Chalk, near Norwich, and placed in the hands of the late Professor Edward 
Forbes for description, whose manuscript name for the same was C. Middeltoni. Under 
this designation a diagnosis of the species was given by my late friend Dr. Woodward, 
in his valuable appendix to Decade V of the ' Memoirs of the Geological Survey,' who 
kindly obtained another specimen, to enable me to give a detailed description of this I'are 
British form ; a careful examination of this fossil, however, has satisfied me that it is 
merely a small variety of Cyphosoma magnijicim, Agassiz, and agrees in all its specific 
characters with the sulcate variety of that species. 

The test is circular, elevated, or moderately depressed on the upper surface, inflated at 
the sides (PI. XXV, figs. 1 a and d) and concave at the base (fig. 1 c). The ambulacral 

18 



138 CYPHOSOMA 

areas are wide; with two rows of tubercles, which are large at the ambitus and base 
and veiy small on the upper surface ; the change from the large ambital to the small 
dorsal tubercles is very abrupt ; the areolae of all the large tubercles are wide and 
confluent, and those of the smaller are surrounded by. circlets of granules. 

The poriferous zones are narrow, and much undulated at the ambitus and infra-mar- 
ginal region ; they are less sinuous above, where the pores are small and unigeminal ; the 
spaces between the pairs of holes often support two small granules (fig. 1 e). 

The inter-ambulacral areas are about one third wider than the arabulacral, and pro- 
vided with two rows of primary tubercles, twelve in each, nearly identical with those in 
the ambulacra; like them, they have wide areolae at the ambitus and infra-marginal region, 
and very small on the upper surface ; the transition from the large ambital to the small dorsal 
tubercles is likewise well marked in the specimen before me (fig. I a, d). A row of small 
irregular secondary tubercles, five or six in each, occupies the spaces between the primary 
series and the poriferous zones (figs. 1 d, d), and disappears among the granules of this 
region. Other secondary tubercles occupy the wide spaces by the zones at the angles of the 
plates (figs. 1 c, e, and figs. 2 a, b), and range in file with the small secondary series on the 
upper surface. The intermediate granules are large and abundant, of unequal size, and 
disposed in circles around the areolae ; these circles at the ambitus are incomplete at 
their basal border (fig. 1 e). The miliary zone is large, much depressed in the middle, 
and nude as it approaches the discal opening (fig. 1 d) ; the small granules forming complete 
circlets around the small tubercles of this region. 

The primary tubercles at the under surface are moderately large, and nearly the same 
size in both areas (fig. 1 c, and fig. 2 b), which imparts a highly ornamented character 
to this region of the test and contrasts strongly with the small tubercles, and the naked 
and depressed miliary zone on the upper surface (fig. 1 d). 

The mouth-opening is small, the peristome circular, and divided into nearly equal- 
sized lobes by feeble incisicms (fig. 1 c). The discal opening is large, pentagonal, angular, 
and elongated in the antero-posterior direction (fig. \ b). 

C^hosoma vnic/nijicum, so rare in England, is a very common species in the south- 
west of France, Avhere two well-marked varieties are found. The/r*/f type of the species 
is characterised by having its ambulacral and inter-ambulacral tubercles large and promi- 
nent at the ambitus, becoming gradually smaller on the upper surface, the miliary zone wide 
and not depressed in the middle. In the second type the transition in size from the large 
ambital to the small dorsal tubercles is more abrupt, the upper part of the miliary zone is 
quite destitute of granules and much depressed in the middle, near the coronal plates, which 
are marked with very distinct sutures ; the areolae at the ambitus are larger and more super- 
ficial, and the under surface has a more ornamented appearance. This variety has been 
described as C. sulcatum, and is that to which our specimen is referred. It attains a much 
larger size than the first or type form, as a specimen collected from the Chalk of Royan 



FROM THE UPPER CHALK. 139 

(Cliarente-Inferieure) measures two and a half inches in diameter, and one incli and 
one tenth in height. 

The English specimens of this Urchin that have hitherto been collected are small 
and immature, they consequently have fewer tubercles in each row tiiau the French 
specimens possess, and the poriferous zones, for a like reason, have the pores in single file, 
the bin;eminal arrangement being a character of more mature age. 

Affinities and Differences. — This species differs so much from its English congeners 
that it is readily distinguished from all of them by its wide anibital areolae and large 
tubercles, and the series of small tubercles on the upper surface, with a secondary row on 
the zonal side. In its general characters C. magnificum resembles C. Archiaci from the 
same stage, but the latter has a more pentagonal test, wider inter-ambulacral areas, 
smaller primaiy tubercles, and four rows of secondary tubercles ; the base likewise is 
flatter, and the mouth-opening larger and more superficial. 

Locality and Stratigraphical Position. — The English specimens have been found only 
in the Upper Chalk at Norwich, where they are extremely rare. 

M. Cotteau states that this species is common in the Etage Senonien inf. at Saint- 
Pierre de Cheville, Saint-Paterne, Saint-Calais^ Marcon (Sarthe) ; Villers, Villedieu (Loir- 
et-Cher); Saint-Christophe, Semblangy (Indre-et-Loire) ; Barbezieux, Aubeterre, Espagnac, 
prcs Angouleme, Charmant, Lavalette (Charente) ; Royan, Talmont, Saintes, Cognac 
(Charente-Inferieure), Saint-Georges pros Perigueux, Tretissac (Dordogne) ; Belbeze 
(Haute- Garonne). 

History. — The table of synonyms gives the history of this species, which was unknown 
to my old friend Professor Forbes, who named the only specimen he ever saw after the 
friend who communicated it for description. 



Cyphosoma Wetherelli, Forbes. PI. XXVH, figs. 1, a — h. 

Cyphosoma Wetherelli, Forbes. In Morris's Catalogue of British Fossils, 2nd ed., 

p. 7f>, 1854. 
— — Woodward. Mem. Geol. Surv., Decade V, Supplement, 

p. 2, 1856. 

Test circular, inflated at the sides, depressed at the summit, and flat beneath ; ambu- 
lacra wide, two rows of large tubercles, nine to ten in each, gradually diminishing in 
size towards the poles ; inter-ambulacra, two rows of primary tubercles, nine in each, 
with a small secondary tubercle in the centre of the zonal margin of each plate; poriferous 
zones narrow, undulated; pores unigeminal throughout; mouth-opening one third the 
diameter of the test ; discal opening large, angular, pentagonal. 

Dimensions. — Transverse diameter one inch; height half an inch. 

Description. — This Urchin very much resembles C. corollare, Klein, but was separated 



140 CYPHOSOMA 

from that species by the late Professor Edward Forbes, and dedicated to N. T. Wetherell, 
Esq., F.G.S., who presented it to the Museum of the Royal School of Mines. This 
unique typical example, partly imbedded in flint, was obtained at Gravesend. The test 
is of moderate size, has a circular figure, and is depressed a little above and below ; the 
sides are inflated and the base is flat ; the ambulacral areas are wide, with two rows of 
large tubercles (figs. 1 c, b), nine or ten in each ; the areolae occupy nearly the entire 
width of the plates, and are bordered by a series of prominent miUary granules, which are 
absent only on the zonal sides of the plates (figs. 1 e, g, h) \ the tubercles gradually 
diminish from the ambitus to the oral (fig. 1 ]i) and the discal apertures (fig. 1 g) ; 
the areolae retain throughout, even to the smallest tubercles, the border of granules special 
to each (figs, g, h). 

The poriferous zones are much undulated, and form a series of crescents around the 
large tubercles (fig. 1, d) ; the rows are narrow, the pores simple and unigeminal through- 
out, and there are from five to six pairs of holes opposite each of the large plates 
(figs, e, g, h). 

The inter-ambulacral areas, a little wider than the ambulacral, have two rows of 
primary tubercles, nine in each, and two rows of secondary tubercles placed near the 
zones, and extending from the peristome to the ambitus (fig. ] c and fig. 1 h). The 
areolae of the primaries are wide, occupying nearly the whole surface of the plates, and 
each is bordered by a row of distinct miliary granules (fig. 1 e), which completely separates 
the areolae from each other. The secondary tubercles are small, and form a short row of 
twelve tubercles set on bosses ; they occupy a space between the zones and the primary 
tubercles (figs. 1 c, //), and extend from the peristome to the ambitus. 

The tubercles of both areas are very prominent, and nearly of the same size; the 
bosses are large, with feebly crenulated sunmiits, closely embracing the mammillou, which 
is large and conspicuous (figs. 1 e and/). 

The miliary zone is narrow at the ambitus, with two rows of granules ; on the upper 
surface it becomes wider, depressed, and nude in the middle, and is sparsely supplied 
there, and at the sides, with very small granules (fig. 1 d). 

The mouth-opening, small and circular, is one third the diameter of the test; 
the peristome is divided into ten nearly equal-sized lobes, by well defined incisions 
(«g. Ic). 

The discal opening is directly opposite to, and of the same proportional size as the 
oral aperture; it has a pentagonal form, and the single ovarial plate that extended into 
the single inter-ambulacrum protruded farther into this area than either the antero- or 
postero-lateral ovarials (fig. 1 6). 

The upper surface of the test is considerably depressed, and the base is fiat. This 
contour of the shell is well shown in fig. 1 d. 

Ajfinities and Differences. — This species has the closest affinities with Cyphosoma 
corollare, of which it may, perhaps, prove to be only a variety. As it is at present a 



PROM THE UPPER CHALK. 141 

uniciun, we wait for the discovery of other specimens with spines before stating with 
confidence its affinitive relations. 

Locality and Strati (jraphical Position. — Poimd imbedded in a flint nodule at Gravesend, 
from the Upper Chalk. . The specimen belongs to the Museum of the Royal School of 
Mines. 



CvPHOsoMA SPATULIFERUM, i^ories,1850. PI. XXVIII, figs. 1«, b, c, d, e,f,g, h; PI. XXIX, 

figs. 1 a, b, c, d. 

Ctphosoma SPATULIFERUM, Forhes. Dixon's Geology of Sussex, pi. xxiv, fig. 20, 

p. 340, 1850. 

— — Forbes. In Morris's Catalogue Brit. Foss., 2Qd ed., 

p. 7.5, 1854. 

— — Woodward. Mem. Geol. Surv., Decade V, Supplement, 

p. 2, 1856. 

Test small, circular, inflated at the sides, concave at the base, and depressed on the 
upper surface ; ambulacra prominent, two rows of tubercles, eight to ten in each ; areolae 
wide, bordered by granules ; inter-ambulacra with two rows of primary tubercles, nine 
in each, and two short rows of secondary tubercles ; areolae wide, bordered by granules. 
Poriferous zones much undulated ; pores unigeminal ; tubercles of both areas nearly 
ahke in size and structure. Mouth-opening one third the diameter of the test ; discal 
aperture peutagonal, large and angular. Spines spatulate, very much flattened, smooth 
except near the base, where there are fine longitudinal lines. 

Dimensions. — Height nine twentieths of an inch ; transverse diameter seven tenths 
of an inch. 

Descrijjtion. — This beautiful little Cyphosoma has a circular body, with inflated sides 
and small projecting equal-sized tubercles ; the ambulacra] areas are prominent, and have 
two rows of tubercles ; fig. 1/ shows one of these segments magnified six times ; the areolae 
are wide, and fill nearly the entire plate ; the inner atd upper margins of each are bor- 
dered by a series of miliary granules, which define the boundary of the areolae, and entirely 
prevent them becoming confluent. The tubercles at the ambitus are a little larger, and they 
gradually become smaller as they approach the two apertures. The narrow poriferous 
zones are much undulated, and form a series of crescents around the large plates ; there 
are, in general, six pairs of holes opposite each plate, and they are entirely unigeminal 
throughout (fig. 1/). 

The inter-ambulacral areas are a little wider than the ambulacral, and composed of large 
plates (PI. XXVIII, fig. 1 y ; PI. XXIX, fig. 1 d), of which there are nine in each column. 
The areolae are wide, and bordered by a circle of miliary granules, complete on five sides 
of the plate, but absent on lower margin (PI. XXIX, fig. 1 d). The miliary zone is 



142 CYPHOSOMA 

narrow at the ambitus, where it is crowded with granules, and wide at the upper sur- 
face, where it is depressed and nearly nude (PI. XXVIII, fig. Id). At the base of the 
area, between the primary tubercles and the poriferous zones, there is a short row of small 
secondary tubercles (fig. 1 c), which extends from the peristome to the ambitus; fig. 1 /i 
shows the base of this segment magnified six times; the small secondaries are raised 
upon bosses (fig. 1 /i). 

The tubercles of both areas are nearly of the same size ; the boss is large, with feeble 
crenulations, closely embracing the mammillon, Avhichis very prominent (PI. XXIX,fig. 1 d). 

The base is concave, and the mouth-opening, one third the diameter of the test, is in 
a slight depression (fig. 1 c). The peristome is divided by slight incisions into ten nearly 
equal-sized lobes. The discal opening is large and pentagonal. The mould of the single 
ovarial plate descends further into the segment than either the antero- or postero- 
lateral ovarials into their respective areas. 

The spines of this Urchin are spatulate, and the stem is extremely smooth, except near 
the milled ring, where the base is marked by fine longitudinal hues. 

Affinities and Differences. — The spatulate form of the spines distinguish this 
species from C. coroUare, with which it has many affinities in the anatomy of the test ; 
C. spatuliferum is, however, a smaller Urchin, more compressed and pentagonal, less 
inflated at the sides, and more depressed on the upper side than C. coroUare ; the surface 
of the test is, likewise, rougher in consequence of the numerous small tubercles that 
project sharply from the plates. 

Locality and Stratigrajjhical Position. — This is a rare species in the Upper Chalk of 
Kent and Sussex. The type specimens of the Dixon Collection are now in the British 
Museum. One of these I have figured in PI. XXVIII, fig. 1 ; and a still larger specimen, 
from the Rev. T. Wiltshire's Cabinet, in PI. XXIX, fig. 1. 

CypHOSOMA RADiATUM, Sori(jnet, 1850. PI. XXIX, figs. 2 a, b, c ; figs. 3 a, b. 

CrPHOsoMA ? (small or young), Dixon. Geol. Sussex, p. x, pi. xxiv, figs. 28 — 31, 1850. 

— RADIATUM, Sorignet. bursins foss. du Dep. de I'Eure, p. 28, 1850. 

— SIMPLEX, i^orif*. Morris's Catalogue of Brit. Foss., p. 74, 1854. 

- — — Woodward. Mem. Geol. Surv., Decade V, App., p. 1, 1856. 

Phtmosoma Heberti, Besor. Synopsis des Echinides foss.. Supplement, p. 450, 

1858. 
CyPHOSOMA PERFECTUM, Cotteau tt Triger (pars). Echinides du Depart, de la Sarthe, 

p. 375, 1862. 
Phtmosoma Heberti, Dvjardin et Hupe. Hist. Nat. des Echinoderm., p. 508, 1862. 

— SIMPLEX, Dujardin et HupL Ibid. 

Ctphosoma r.\diatum, Cotteau. ^Paleontologie Fran^nise ; Ter. Cret., pi. 11-1", fio-s. 

10—14; pi. 1148, p. 609, 1864. 

Test small, subpentagonal, convex above, base concave; ambulacra, two rows of 



FROM THE UPPER CHALK. 143 

tubercles, eight in each, with large confluent areolae at the ambitus ; inter-ambulacra, two 
rows of primary tubercles, nine to ten in each, with two short rows of small secondaries 
at the base ; primary tubercles prominent at the ambitus, small and inconspicuous above ; 
areolse large, radiated, and nearly confluent at the middle, very small above ; poriferous 
zones undulated, unigeminal ; pores small. 

Dimensions. — Height three tenths of an inch ; transverse diameter six tenths of an 
inch. 

Descrij)tion. — This beautiful little species occurs in the hard gritty Chalk of Dover. 
The test is more highly ornamented than any of the preceding forms ; the tubercles at 
the ambitus are highly developed, with radiated areolae, and nearly all of the same size. 
On the upper surface they are proportionally small. The ambulacral segments slightly 
project; this imparts a subpentagonal form to the body (fig. 2 a). There are two rows 
of tubercles therein, eight in each, those at the ambitus being very large, and those on 
the upper surface very smafl (fig. 2 c). The areolae of the large ambital tubercles are 
confluent, and the smaller ones are separated from each other by a few granules 
(fig. 2 c). 

The poriferous zones are narrow and much undulated (fig. 3 «) ; at the ambitus the 
pores are small and unigeminal, and there are five pairs opposite each of the larger 
plates. 

The inter-ambulacral areas are a little wider than the ambulacral, with two rows of 
tubercles, nine to ten in each. The areolae are wide ; those at the ambitus and superior 
surface have a radiated border at the circumference, the radii being formed of elongated 
granules developed into a pyriform shape ; (fig. 3 b) represents four central plates 
of an inter-ambulacral segment magnified eight times. In some of the plates small 
miliary granules are introduced within the rayed circle. 

The discal opening is large, and of an elongated pentangular shape; the angle cor- 
responding to the single inter-ambulacrum projecting far down that segment (figs. 2 a 
and b). 

Affinities and Differences. — This species in its general facies resembles C. spatdiferum, 
but differs from it in having the tubercles on the upper surface disproportionately small 
when compared with the large size they attain at the ambitus (figs. 2 b, c). This character 
is very evident when fig. 2 c, PI. XXIX, is compared with fig. 1/ PI. XXVIII. The 
radiated structure of the areolae is likewise another good diagnostic character between these 
nearly allied forms. M. Cotteau appears to consider C. Wetherelli and C. spatdiferum 
as varieties of C. striatum ; but, after a careful comparison of the specimens themselves 
and with each other, I must dissent from this opinion. However much the tests of 
JEchinida per se may resemble one another, still we must not forget that the shell alone is 
not the complete body of the animal, and that without its spines our evidence of specific 
identity is incomplete : for example, the test of Hemicidaris crenularis, Ag., is identical 
with Hemicidaris intermedia, Flera. ; but the spines of the former are very different 



144 SALENIDyE 

from those of the latter, and without these appendages it is impossible to distin- 
guish the test of the one Urchin from that of the other, and the same conditions 
may be true of the tests of other, nearly allied forms. C. WethereUi may be con- 
sidered a variety of C. coroUare until proof to the contrary is discovered ; but the 
structure of the test of C. spatuliferum and the remarkable form of its flattened spines, 
when compared with the test and spines of C. coroUare, afford presumptive evidence that 
they are distinct forms. It is very desirable to diminish the number and correct the 
synonyms of species in our lists ; to do this, however, correctly requires much literary 
research and a critical examination and comparison of the specimens themselves, before 
a true solution of the difficulty can be arrived at ; and in doing all this the best ob- 
servers very often confuse analogy with identity of structure, from the imperfect materials 
upon which they are too often obliged to work. 

LocaJUy and Slratigrapldcal Position. — Cyphosoma striatum is usually found in the 
hard, gritty beds of Lower Chalk near Folkestone, and occasionally in the Upper Chalk 
with flints in Sussex. 

The type specimen figured in PI. XXIX belongs to the Museum of the Royal School 
of INIines. I have examined several others collected by my kind friend, the Rev. T.Wiltshire, 
F.G.S., from the Lower Chalk, near Folkestone, where he found it associated with 
Salenia granulosa, Forb. 

SALENID.E. 

Family 5. — Salenid^, Wright, 1856. 

This natural family nearly corresj)onds to the Salenies of MM. Agassiz and Desor, and 
is distinguished from other families of the Echinodea Endocydica by the peculiar structure 
and great development of the apical disc, which, besides the five genital and five ocular 
plates, has an additional or sur-anal plate, developed in the centre of the disc, immediately 
before the anal opening ; this plate in some genera is single, in others it is composed of 
from one to eight separate elements. 

The test is thin, and in general small, spheroidal, hemispherical, or depressed ; the 
ambulacral areas are always narrow, straight, or flexuous, with two rows of granules or 
small tubercles, that alternate with each other on the margins of the area. 

The poriferous zones are narrow ; the pores unigeminal, except near the peristome, where 
they fall into oblique ranks of threes. 

The inter-ambulacral areas are wide, with two rows of primary tubercles, which have 
large bosses and crenulated summits ; in Acrosalenia and Pseudosalenia the tubercles are 
perforate, in Peltastes, Goniojjhorus, and Salenia they are imperforate. The mouth-opening 
differs in size in the different genera ; the peristome is more or less decagonal, and 



SALENID^. 145 

sometimes deeply notched, or only feebly indented. The jaws are known in one genus, 
in which they resemble those of Hemicidaris. 

The spines in Acrosalenia are long, slender, angular, or flattened, and the surface of 
the stem, although apparently smooth, is covered with very fine longitudinal lines. In 
Pseudosalenia they are enlarged, ovoid, snb-glandiform, and more or less granular; in 
PeUastes and Salenia they are elongate, aciculate, straight, curved, or bent. 

From a misconception of the true relative position of the elements of the apical disc in 
this family, much confusion exists in the works of diffei-eut authors in the description of 
this part of the test. " The great difficulty in the study of this group," says M. Desor,' 
" is to find the place of the madreporiform body ; we are consequently embarrassed when 
we attempt to assign the lateral parts to the longitudinal axis of these animals, unless we 
admit that the sur-anal replaces the madreporiform body ; but this would be contrary to 
all analogy, because in all the other Cidarides the madreporiform body is an integral part of 
one of the genital plates. M. Agassiz got rid of the difficulty by means of an hypothesis, 
by admitting that the sur-anal plate is invariably placed in the plane of the animal, that it 
therefore could only be anterior or posterior; hence his two divisions in the genus Salenia, the 
first with a sur-anal plate posterior, and, consequently, with the periprocte excentral and 
before; the second with the sur-anal plate anterior, and, consequently, with the periprocte 
excentral and behind."^ 

Professor Johannes Midler assigns the left posterior genital plate as the bearer of the 
tiiadreporiform body in Saletiia persona/a. " Dies wird auch durch die Salenien bestatigt, 
wo die Langsachse durch die plaque suranale vor dem After bestimmt wird. An einem 
im mineralogischen Museum aufbewahrten ausgezeichnet schonen Exemplar der Salenia 
personafa. Ag., mit vorderem After, Taf. I, fig. 9, ist die linke hintere Genitalplatte poros 
und Madreporenplatte." ^ 

I have selected fine specimens of PeUastes Wriglitii, Desor, from the Lower Green- 
sand, PeUastes Austeni, Forbes, from the Lower Chalk, and Salenia petalifera, Desniarest, 
from the Upper Greensand, and in all of these the madreporiform body occupies the 
surface of the right anterior genital plate, as in the Cidaridce, Hemicidarida, Biademadce, 
and EcJiinida. The sur-anal plate is central, and the anal opening posterior in a line with 
the axis of the body, or inclined to the right side. In fact, the madreporiform body and 
sand canal, whatever their true functions may be, have the same position in all the 
Echinidea, recent and fossil, which I have examined, and probably the same in all 
Echinodermata. Professor Midler's mistake, therefore, may have arisen from jjlacing the 
Salenia in a false position before him. The study of the apical disc in the Acrosalenia 
reveals the true relation of its elements to each other, and jjroves that the sur-anal plate 

1 ' Synopsis des i5chiiiiiJes fossiles,' p. 138. 

2 For further details on this subject, M. Agassiz's 'Monographies d'Echinodermes: premiere Monographie 
des Salenies,' may be consulted. 

3 Job. Miiller, ' Ueber den Ban der Echinodernien,' p. 7. 

19 



146 



SALENID^. 



has nothing in common with the spongy madreporiform body which occupies tlie surface 
of the right anterior genital plate (PL XV, fig. 4, a, t). I had the good fortune to make 
this discovery some years ^ ago, when figuring and describing Acrosalenia hemicidaroides, 
which urchin has furnished a key to the true relation of the bilateral parts to the longi- 
tudinal axis of the SALENiDiE. On this point M. Desor observes : 

" Nous devons en outre a M. Wright une autre decouverte plus iraportante, celle du 
corps madreporiforme, qui fait partie integrante de I'une des plaques genitales corame dans 
les autres Cidarides. Or comme nous savons maintenant que cette plaque a une position 
fixe dans tons les oursins, nous sommes par la meme en raesure de determiner Pavant et 
I'arriere de ces animaux ; et puisque les plaques sur-anales sont situees eu arriere de cette 
plaque, il s'ensuit que le periprocte se trouve reellement refoule en arriere. II ne peut 
des-lors plus etre question d'Acrosalenies a periprocte eccentrique en avant, corame on 
supposait que c'etait le cas de \' Acrosalenia tuberculosa" &c. 

" II n'arrive que trop souvent que le disque apicial manque, et dans ce cas, il est tres 
difficile de distinguer les Acrosalenies du genre Hemipedina decrit-ci-dessus. Cependant, 
comme par suite du refoulement du periprocte en arriere la plaque genitale impaire ou 
posterieure gagne plus que les autres sur le test, on peut encore, d'apres M Wright, 
reconnaitre la place de cette plaque meme dans les individus depourvus d'appareil apicial." ' 



Family. Sections. 



Genera. 



03 C9 



< ^ 



Qj ■ 1 r- 

2Q £^ o 






S / 

-5 
< 
(/3 



O 

£ g 

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^ 0^ r- 

55 -72 «! 



A Table showing the Classification of the Salenid^. 

Diagnosis. 
Ambulacral areas straight, large, with two rows of small , 
tubercles ; apical disc small and not prominent ; sur-anal plate I Acrosalenia Ao-assiz 
composed of one or many pieces granulated on the surface ; 
vent posterior and central in the axis of the test ; spines long. 

Ambulacral areas narrow, flexed, with two rows of granules ; 
apical disc prominent, not granulated, and marked with impres- 
sions ; vent exceutral posterior, in the axis of the test ; spines I 
'•enlarged, ovoid, sub-glandiform, more or less granular. J 

Inter-ambulacral tubercles moderate; apical disc large and] 
prominent; genital plates in the form of elongated lobes ; sur- I 
anal plate single ; vent posterior and central in the axis of the | 
test. 



Pseudosalenia, Cott. 



I Peltustes, Agassiz. 



— s- 



luter-ambulacral tubercles large, few in number ; apical disc 
large, and forming a regular pentagon, with elevated angular 1 
carinae independent of the sutures ; sur-anal plate angular; vent <?<'«»o?^'""«*. Agassiz. 
large, escentral, oblong, and posterior. j 



Inter-ambulacral tubercles large ; apical disc wide and very solid, 

with an undulated circumference ; surface of the large plates 

ornamented with punctuations or sculptured figures along the 

line of the sutures ; sur-anal plate single ; vent posterior ex- 

> central and directed towards the right side. 



V Salenia, Gray. 



^ Wright, 'Annals and Magazine of Natural History,' 2nd series, vol. viii, p. 261. 
2 ' Synopsis des Echinides fossiles,' p. 140. 



SALENID^. 147 

M. Cotteau thus describes the family " Salenidees," Wright : — Pores disposed in single 
pairs; ambulacra sometimes large, straight, and presenting a double range of small 
tubercles ; sometimes narrow, and undulated, and garnished with granules ; interambu- 
lacral tubercles few in number, largely developed, perforated, or imperforate, always 
crenulated. Peristome sub-decagonal and furnished with entailles. Periprocte excentric 
and posterior, placed in the axis of the animal or inclined a little to tlie right side. 
Apical disc very large, solid, most often marked with deep depressions, composed of five 
ovarial plates and five ocular plates perforated, with one or many sur-anal plates which 
determine the excentricity of the periprocte. Madreporiform plate distinct, diSerent 
from the others by its spongy aspect and sometimes by a simple laceration, a fissure more 
or less large which corresponds to the genital pore and seems directed invariably to 
the left side. The spines are sometimes elongate, aciculate, or sub-cylindrical, fm-nished 
with fine longitudinal stria3 in the Acrosalenia heiuicidaroides, Wright, sometimes 
enlarged, ovoid, sub-glandiform, more or less granular, as in the Pseudosalenia tuberculosa. 

The SaleniDjE are divided into two natural groups. 

1st. The Acrosalenia have narrow ambulacra gradually enlarged towards the oral 
aperture and provided with perforated tubercles more or less developed ; the 
peristome is divided into two lobes by deep incisions ; the apical disc is very large and 
provided with a sur-anal plate composed of one or many elements ; in consequence of 
the number of small sur-anal plates, and their feeble union with each other, they are 
seldom preserved. 

2nd. The SalenicB, and the genera dismembered from them, have narrow ambulacra, 
often undulated and garnished with tubercles; their peristome is feebly incised; the 
apical disc is large and solid, projecting beyond the surface, and more or less deeply 
marked with impressions at tlie sutures of the plates. 

The Acrosalenia: resemble Hemicidaris and llypodiadema, except in the sti'ucture 
of the apical disc, and when this portion is absent it is often difficult to determine the 
genus to which the mutilated specimen belongs ; but the great size of the discal aperture, 
and the extension of the single ovarial plate into the single inter-ambulacrum readily 
enable the trained eye of the observer to distinguish it from Hemicidaris. 

The SalenicB, on the other hand, resemble the CidariDvE by their narrow sub-flexuous 
ambulacra, furnished with granules, their wide inter-ambulacral areas, their large primary 
tubercles, and the inflated ovoid or sub-glandular spines, sometimes supported on them ; 
their peristome is likewise feebly incised, like that of Cidaris. 

The Acrosalenice form only a single genus, the species of which, with one exception, 
are distributed throughout the Jurassic rocks. 

The Siilenm have certain distinctive characters l)y which they are readily distinguished 
from the Acrosalenice. 1st. Their tubercles are all imperforate, and 2nd, the position of the 
vent, or periprocte, is always excentric and posterior; sometimes it is situated in the axis 
of the body, and sometimes out of the axis, and inclines to the right side. For this reason 



J48 SALENIDiE. 

MM. Af^assiz and Desor have separated from the true Saleni(B the genera Peltastes and 
Hyposaleuia. By the same authors a doubt has been suggested about the vahie of this 
character, as it may be only an accidental and variable condition ; to this objection 
M. Cotteau replies, " that he has examined more than four hundred specimens of Salenice 
appertaining to the different stages of the Cretaceous formations, and representing almost 
all the known species, many among which, such as Peltastes acanthoides, P. Studeri, Salenia 
2}etalifera, 8. Predensis, and 8. Bourgeoisi present characters that are clearly defined. 
Nevertheless we have recognised in each of those species that the periprocte, whether 
in the axis of the animal or out of the axis, occupies a place which is invariably the same." 

The structme of the apical disc, and the lines and impressions marked thereon, afford 
a character of secondary importance, for although the general outline of these sutures is 
remarkably constant, still there are exceptions which show that caution must be exercised 
in using it, along with others, in the determination of species. The size of the ambulacra, 
and the number and magnitude of the granules contained therein ; the form of the 
test, the size of the inter-ambulacral tubercles ; the dimensions of the oral aperture, the 
structure of the peristome, and the depth of the incisions or eutailles, collectively form 
good specific characters on which we can rely. 

M. Cotteau divides the family Salenid^ into six genera, of which he gives the 
opposable characters in the following table.^ 

A. Ambulacra large, straight, furnished with small tubercles; apical disc 

with a compound sur-anal plate, the elements of which are covered K. Acrosalenia 
with granules. 

B. Ambulacra narrow, sub-undulated, furnished with granules; apical 

disc large, prominent ; sur-anal plate single ; elements large shield- 
shaped, marked by regular impressions. 

o. Tubercles perforated. 

X. Periprocte excentral and posterior, situated in the 



[ PSEUDOS 

XX. Periprocte excentral and posterior, situated with- ) 



. , . OSALENIA. 

axis of the animal 



, f Heterosa],enia. 

out the axis of the body ) 

h. Tubercles imperforate. 

X. Periprocte excentral and posterior, situated in the"") 

axis of the animal. „ 

, . II 1 • ,. ■,. ^Peltastes. 

1. Ambulacra destitute of poriferous impres- 

sions J 

2. Ambulacra furnished with poriferous im- ) _, 

\ GONIOPHORUS. 

pressions ; 

XX. Periprocte excentral and posterior, situated with-^ 

out the axis of the body and inclined to the ( Salenia. 
right side \ 

1 ' Paleontologie Franjaise ; Terrain Cretace,' tom. vii, p. 90. 



PELTASTES. 149 

The family Salenid^ commenced their life-career in the lower zone of the Inferior 
Oolite. Acrosalenia abound in the Inferior Oolite and the Cornbrash ; and one is found in 
the Coralline Olite. Pseudosalenia was discovered in the Corallian of the Haut Jura. 
Ileterosalenia is represented by one solitary species in the Chalk with Hippurites (Senonieii 
Inferieur). Peltmtes and Gonioj^horns are found chiefly in the Lower Cretaceous. Salenice 
occur in the Lower, Middle, and Upper Cretaceous rocks ; and in the Tertiary Numraulitic 
limestone of Biarritz, are represented by a curious species, Salenia Pellati, recently found 
in that formation. Our present seas contain, we are told, a representative form of this 
family, which was recently dredged up off the American coast by the deep-sea dredging- 
operations performed in 1869 ; beyond the alleged fact I know nothing whatever of the 
genus to which this existing form belongs. 



Genus — Peltastes, Acjassiz, 1838. 
Salenia (pars), Agassiz, 1S3S. Hyposalenia, Desor, 1856. 

Test small, circular, more or less inflated above, and almost flat below ; pores simple 
in the zone and crowded near the peristome ; ambulacra straight, or slightly flexuous, fur- 
nished with two rows of small, close-set, homogeneous mammillonated granules. Inter- 
ambnlacra large, provided with two rows of large, crenulated, imperforate tubercles. 

Mouth-opening moderate in size, peristome divided into unequal lobes by feeble 
incisions. Periprocte excentral and posterior, situated in the line of the animal's axis. 
Apical disc shield-shaped, composed of large plates, more or less undulated at the 
border; the disc covers in general a large portion of the upper surface of the test, and 
is marked by sutural impressions and striae that vary in the different species ; the right 
antero-lateral ovarial plate has an oblong fissure always directed from right to left, 
corresponding to the oviductal pore and representing the madreporiform body. 

Peltastes in its general form and structure resembles Salenia ; it is distinguished from 
the latter, however, by the position and direction of the periprocte, which is excentral, 
and directed obliquely backwards and outwards and towards the right side ; the ambulacra 
likewise are less flexed, the mouth-opening is smaller and lies in a deeper depression ; 
the madreporiform fissure in the right antero-lateral ovarial plate is smaller. 

The genus Peltastes was established in 1838 by Professor Agassiz j and in 184G 
MM. Agassiz and Desor comprised in the genus all the Saleniad^ in which the periprocte 
was situated in a line with the axis of the animal, and this forms the leading character 
by which it is distinguished from Salenia. 

The genus Peltastes is special to the Cretaceous formations; it commences with some 
remarkable forms in the Lower Greensand, appears in full force in the Upper Greensand and 
Lower Chalk; becomes rare in the Upper Chalk, and finally disappears from its upper stages. 



150 PELTASTES. 



A. Sjjecles fro7)i the Loiver Greensand or Neocomian. 

Peltastes Wrightii, Desor. PI. XXX, fig. 1 a—f, fig. 2. 

Salenia punctata, Forbes. In Morris' Catalogue of British Fossils, 2nd ed., 

p. 89, 1854. 
— — Woodward, Memoirs of Geol. Surv., App. to Decade V, 

p. 7, 1856, 
Hyposalenia Wiughtii, Besor. Synopsis des Echinides fossiles, p. 148, 1856. 
Peltastes — Cotteau. Paleuntologie Fran9aise ; Terrain Cretace, tome 

vii, pi. 1028, figs. 1—7. 

Biarjnosis. — Test circular, upper surface convex, sides inflated, under surface flat, 
ambulacra narrow, slightly flexuous, with two rows of granules fifteen in each, equal in 
size, and manimillated ; poriferous zones slightly flexed, pores unigeminal, set in oblique 
pairs, and multiplied around the peristome ; inter-ambulacra wide, with five or six large 
prominent tubercles, increasing in size from the peristome upwards. Apical disc very 
large, convex, subcircular, plates smooth, sutures marked with isolated points, periprocte 
transversely oblong, a little prominent; mouth-opening large, peristome divided by 
feeble indentations into ten lobes. 

Dimensions. — Height six tenths of an inch ; transverse diameter one inch. 

Bescription. — Tiiis beautiful typical form of Peltastes, and the oldest we at present 
know, appears in our lists of English fossils as Saletiia punctata, one of the synonyms of 
Peltastes stellulatus. A comparative study of specimens, however, convinced M. Desor 
that the identification was erroneous ; and he described^ our Earringdon urchin as a well- 
marked and distinct species, resembling Peltastes stellulatus, but separated from it in 
havinc a more inflated test, with more numerous and less prominent tubercles, the apical 
disc thinner and smoother, and marked only with some isolated punctations. 

The test is circular, the sides are a little inflated, and the upper surface is convex and 
depressed ; the ambulacral areas are narrow and very slightly flexed with two rows of 
mammillated granules, about fifteen in each. They are very uniform in size and arrange- 
ment throughout the area, except at the base, where two pairs are a little larger ; a line 
of microscopic granules down the middle of the area divides the larger lateral rows from 
each other (PI. XXX, fig. 1 e). The poriferous zones are wide for so small a test, and 
the pairs of pores are obliquely but very regularly arranged in a unigeminal series ; near 
the peristome, however, they become a little more crowded and doubled. 

The inter-ambulacral areas are wide, and in the large specimen I have figured fig. 1 a 



1 <■ 



Synopsis des Echinides fossiles,' p. 148. 



FROM THE LOWER GREENS AND. 151 

there are six plates in eacli column ; the tubercles increase in size from the peristome 
upwards, so that the three upper pairs of tubercles are the largest and most prominent 
of the series (fig. 1 d and fig. 1/). A few large mammillated granules, unequal in size, 
are arranged round the areola and in the miliary zone ; a double row of smaller granules 
occupy the middle space ; the tubercles are raised upon large bosses with deeply crenu- 
lated summits, and the mammillon is prominent, projecting, and imperforate (fig. 1/). 

The apical disc is very large, convex, subcircular, and entirely smooth, presenting in 
the line of its sutures two or three isolated superficial punctations in some of them 
(fig. 1 b) ; the sur-anal plate occupies the centre of the disc, and is situated immediately 
before the vent ; in one example (fig. 2) however, it is abnormal and rudimentary, and 
forms an exceptional variety in an otherwise remarkably regular and symmetrical structure. 
Of the many specimens of this Urchin that have passed through my hands this is the only 
exception that has come under my notice. All the ovarial plates are perforated near the 
centres of each ; the madreporic laceration is small, but very distinct in the rio-ht 
antero-lateral ovarial (fig. 1 h). The periprocte is sub-elliptical, rounded anteriorly, an o-ular 
posteriorly, and somewhat elevated and inflated at the border (fig. 1 b and fig. 2). 

The base is flat and the mouth-opening large, one half the diameter of the test (fio-. 1 c). 
The peristome is circular and divided by feeble incisions into ten nearly equal-sized 
lobes. 

Affinities and Differences. — This species presents great uniformity in its specific 
characters, after a careful examination of a great many specimens I have found very little 
variation from the type form I have figured and described. This specimen, belono-ino- to 
the British Museum, is unexceptionally large, and perfect in all its parts. Smaller 
specimens are, however, equally good for description. Tlue Sponge-gravel in which this 
Urchin is most commonly found is in general a very bad matrix for the preservation of the 
tests of Echinidse ; when shielded by a ferruginous crust, derived from the matrix, the 
more delicate portions of the urchin are wonderfully preserved. P. Wrightii resembles 
P. stellulaius ; it is separated from that form by having a greater number of less promi- 
nent tubercles in the area ; the apical disc is likewise thinner and smoother, and the sutural 
punctations are more isolated and more feebly marked. 

Locality and Stratigraphical Position. — I have collected Peltastes Wrightii from the 
Sponge-gravel bed of the Lower Greensand near Farringdon, Berks; it has been found 
likewise in the Lower Greensand at Hythe, Kent; and at Atherfield and Sandown 
Isle of Wight ; it is, therefore, a true Neocomian or Lower Greensand form. 

History. — This species is a very distinct form, and has been separated by Professor 
Desor from P.pimctatus, with which it had been identified by most of our English authors. 
The accuracy of this determination has been sanctioned by M. Cotteau, who has given a 
very good description of the species, with excellent figures thereof, in his great work on 
the Cretaceous Echinida3, in the ' Paleontologie Frangaise.' 



152 



PELTASTES. 



Peltastes stellulatus, Agassiz, 1846. PL XXXI, figs. 1, 2, 3 ; PI. XLI, fig. 1 a^g. 



SaLENIA STELLL'LATA, 



Agassi:. Monog. des Saleiiies, pi. ii, figs. 2.5 — 32, p. 

15, 1838. 
Agassiz. Ibid., pi. iii, figs. 1 — 8, p. 16. 
Agassiz. Echin. foss. de la Suisse, pi. xxiii, figs. 6 — 10, 

p. 90, 1840. 
Agassiz. Ibid., figs. 11 — 15, 18-10. 
Agassiz et Desor. Cat. raison. des Enhinides, Ann. Sc. 

Nat, 3e ser., torn, vi, p. 342, 1846. 
Agassiz et Desor. Ibid. 
— Marcou. Jura salinois, Me'm. Soc. Geol. de France, 2eser., 

t. iii, p. 140, 1848. 
pentagonifeba, A. Gi-as. Ours. foss. de I'lsere, p. 29,pl. i, figs. 11,12,1848. 
Bronn. Index Palseontologicus, p. 1008, 1849. 
D'Orbigng. Prod, de Paleont. strat., t. ii, p. 89, 1850. 
VOrbigmj. Ibid. 

Cotteau. Catal. des Echinid. ne'ocomiens, 1851. 
Bronn. Leth. Geognost., Kreidegeb.,pl. xsix, fig. 5, 1852. 
Desor. Synops. des Echinid. foss., pi. xx, figs. 6 — 8, 1856. 
Desor. Ibid. 

Pictet. Trait(? de Paleont., 2e ed., t. iv, p. 248, 1857. 
Pictet. Ibid. 
Ibid. 
Ibid. 



- areolata, 

stellulata, 

areolata, 

Peltastes stellulatus 

— punctata, 



SaLENIA STELLUL.4.TA, 

Peltastes — 
— punctata, 

Peltastes stellulata, 



Hyposalenia — 

— punctata, 

Peltastes stellulata, 

— punctata, 

— PENTAGONIFERA, PiCiTei. 

— COURTAUDINA, Pictet. 



— stellulata, 

Hypos.alenia — 
Peltastes stellulatus, 



Leymerie et Raulin. Geol. de I'Yonne, Stat. geol. du dep. 

de I'Yonne, p. 420, 1858. 
Leymerie et Raulin. Ibid. 

Cutteau. Ech. foss. de I'Yonne, pi. 54, figs. 1—10, 1859. 
Cotteau. Paleontol. Fran9aise ; Terrain Cretace, pi. 1023, 

p. 100, 1862. 



Diapwsis. — Test small, circular, convex above, flat below, poriferous zones straight, 
formed of oblique pairs, ambulacra straight, two rows of homogeneous mammillated 
granules, set closely together, fourteen in each row. Inter-ambulacra wide, two rows of 
tubercles, five in a row, unequal in size, large at the ambitus, and small near the base ; 
apical disc very large, round, and depressed ; sutures well marked with isolated points, and 
fine incisions ; madreporic fissure small, distinct, and surrounded by an elevation of 
the plate. 

Dimensions. — Height three tenths of an inch ; transverse diameter half an inch. 

Description. — The table of synonyms affords evidence how changes of form in certain 
parts of an Urchin lead to confusion in the identification of the species, and how impossible 
it is to define in a few words certain organisms among which the same structures vary much 



FROM THE LOWER GREENS AND. 153 

in different individuals with age and the changing conditions of their existence. The 
apical disc of Peltastes stellulatus, Ag., is one of these ; M. Cotteau remarks' 
that the ovarial plates are sometimes almost smooth, and present Jiardly any isolated 
points, as in P. pentagoniferus, Gras. In certain examples the number of these points 
augment sensibly, and the plates remaining perfectly smooth, the lines of the sutures are 
punctuated {P. pundatus, Ag.). Instead of isolated points, the sutures are often marked 
with lines or incisions which extend along the surface of the plates, and give to the apical 
disc a very remarkable parsley-leaved aspect (P. stellulatus. Kg.). Sometimes this charac- 
ter is exaggerated ; the incisions become deep, and penetrate even into the interior 
of the plates, which unite at certain points, and produce a remarkable variety of disc seen 
in certain specimens collected from the calcaires a Ecldnospatagus cordiformis in the 
environs of Auxerre. In other examples, the plates independent of the points, more or 
less elongated which exist on the suture, ai'e bordered by little flexuous bourrelets, which 
become attenuated as they approach the centre, as in P. Court audiims, Cot. These varie- 
ties, when studied separately, as they were discovered by different observers, were 
regarded as so many distinct types ; but a careful comparison of the series has taught M. 
Cotteau that they are only so many varieties of the same species. The admirable figures 
given of these variations fully confirm my learned friend's conclusions on the unity of the 
species. The structure of the apical disc forms, therefore, an important character in the 
history of this species ; and as the observations that have been made upon the differences 
noted on the ornamentation and sculpture of its elements are applicable to other forms of 
Peltastes, the careful study of this structure requires thoughtful notice in making a 
diagnosis of all supposed new forms of Salenidse. 

The ambulacral areas are quite straight (fig. 1 b), and between the two lateral rows 
of mammillated granules a zigzag line of microscopic graniUets extends from the base to 
the summit (fig. 3 b). 

The inter-ambulacral areas are wide and furnished with two rows of tubercles having 
crenulated bosses and imperforate mammillous; they are prominent, unequal in size, 
largest at the ambitus, and decrease towards the peristome; very large mammillated 
granules fill up the miliary zone and form very regular circlets around the primary 
tubercles. Between these granules in well-preserved specimens a number of microscopic 
granulets are seen closely arranged around their base. 

The mouth-opening lies in a slight depression, and the peristome is divided into ten 
lobes by feeble incisions, with reflected borders (fig. 2). 

The vent is transversely oval (fig. 3 a), and the periprocte has a slightly elevated and 
inflated border. 

A variety of "Peltastes stellulatus, Ag., figured in detail (PI. XLT, fig. I a — g), was col- 
lected by the Rev. T. Wiltshire, F.G.S., from a greenish yellow band of the Red Chalk 
at Speeton, Yorkshire. The trite position of this specimen was between the upper por- 
1 ' Pal^ontologie Fran^aise, terrain Cr^tace,' t. vii, p. 102. 

20 



154 PELTASTES 

tion of the Gault and the base of the Upper Greeiisand ; this stratum, about nine feet 
thick, contained small GryphtecB and TcrebratuJa semit^lobosm with the Peltasfes ; and 
few fossils besides these. The apical disc (fig. 1 b) shows many punctuations in the line 
of the sutures ; one entire ambulacraj magnified four times, is shown (fig. 1 /), and 
one entire inter-ambulacra, equally enlarged, in fig. \ e ; the structure of a single plate, 
magnified six times, in fig. 2 y, and the disc isolated, magnified foiu* diameters, is shown 
in fig. 1 d. All these figures are drawn with the utmost care and truthfulness for 
comparison with other varieties of this species collected from the Sponge-Gravel of 
Farringdon and figured in PI. XXXI, figs. 1 — 3. For an account of the Red Chalk of 
Speeton, in which this Peltastes was collected, the reader is referred to page 8 of this 
Monograph. 

Affinities and Differences. — P. stellulatus resembles P. Wrightii, but, according to 
M. Cotteau, the species are quite distinct. M. Cotteau had a large series of the different 
varieties of P. stellulatus to compare with specimens of P. Wrightii from Farringdon, sent 
him by my lamented colleague, Professor Edward Forbes, and after a careful study of 
these fossils my learned friend observes, it is true, that P. stellulatus (var. punctata) 
closely resembles P. Wrightii, but nevertheless it is separated from it by its form being 
more inflated, its tubercles more numerous and less prominent, its apical disc more smooth, 
less thick, and marked only with some isolated points.' 

Locality and Stratigraphical Position. — This species, which is very rare in England, 
was collected from the Lower Greensand at Farringdon, Berks, and the Red Chalk at 
Speeton, near Filey Bay, Yorkshire. 

It is abundant, according to M. Cotteau, in France, in the Neocomien inf. et moyen 
at Saint-Sauveur, Fontenoy, Leugny, Auxerre, Bernonil, Tronchoy (Yonne) ; Marolles, 
Soulaines (Aube) ; Saint-Dizier (Haute-Marne) ; Germigney (Haute-Saone) ; Fontanil 
(Isere) ; Ceuseau, les Rousses (Jura), where it is abundant ; and in Switzerland, 
according to Professor Desor, in the etage Valanginien or Neocomien inf. at La Chaux- 
de-Fonds, Sainte-Croix, Hauterive, Lauderon pres Neuchatel. 



Peltastes Lardyi, Desor. PI. XXXI, fig. 4 a, b, c, d. 

Hyposalenia Lardyi, Desor. Synops. des Echinides Fossiles, p. 148, 1856. 
Salenia acupicta, Desor. Ibid., p. 152. 

Hyposalenia Lakdyi, Pictet et Benevier. Foss. du terr. Aptien de la Perte du Rhone, 

p. 161, 1858. 
Peltastes Lardyi, Cotteau. Paleontologie Fran9aise, terr. Cretace, t. vii, p. 106, 

pi. 1024, 1862. 

Test circular, upper surface convex, under surface flat, sides inflated, poriferous zones 
straight, ambulacra narrow, straight, two rows of homogenous mammillated granules, 
' 'Paleontologie Fran^aise, terrain Cretace,' t. vii, p. 105. 



FROM THE LOWER GREENSAND. 155 

eighteen in each. later-ambulacra wide, two rows of tubercles, five to six in each, largest 
at the ambitus. Apical disc large, circular, with undulating borders. Moutli-opening 
circular, peristome decagonal, vent transversely oval. 

Dimensions. — Height four tenths of an inch ; transverse diameter eight tenths of 
an inch. 

Description. — This Salenia, belonging to the British Museum, is a very rare 
form, and was referred by my late friend Dr. Woodward to P. Lardyi. The test is 
circular with inflated sides ; the upper surface is convex and elevated, and the base is flat. 
The poriferous zones are straight, formed of oval pores arranged in obUque pairs ; 
separated a small granule, and unigeminal, throughout, except at the base, where they are 
a little crowded. 

The ambulacral areas are straight, with two rows- of marginal homogenous, mani- 
millated, granules, eighteen in a row (fig. 4 c, d) ; between the rows there are a double 
series of microscope granulets filling in the spaces. 

The inter-ambulacral areas are large, with two rows of tubercles, five to six in 
each (fig. 4 d), largest at the ambitus, diminishing above towards the disc, and below 
towards the peristome ; a double row of large mammillated granules extends down the 
middle of the area, and forms circlets around the tubercles ; a large mammillated 
tubercle occupies the outer angle of each plate near its union with the poriferous zones 
(fig. 4 c, d). Around the base of these granules a number of small granulets are freely 
distributed ; the surface of the test has therefore a highly ornamented appearance. 

The apical disc is large and undulated at the border ; in our specimen (fig. 4) the 
sutures are much filled in, and the typical character of the species is thereby obscured. 
In the beautiful specimens from the Aptien of Auxerre the sutures are sharply engraved 
with isolated points and lines of incision, so as to impart a parsley -leaved character to all 
the elements of the disc. The vent is moderately wide and transversely oval, and the 
rim of the periprocte is a little elevated. 

The mouth-opening lies in a slight depression, it is about half as wide as the diameter 
of the test. The peristome is decagonal, and marked by feeble incisions ; of the ten 
lobes those over the ambulacra are the largest. 

Jffinilies and Differences. — In its form and general characters P. Lardyi approaches 
P.stelhdafus; it is, however, a larger Urchin, with its upper surface more convex and inflated, 
sometimes it even assumes a sub-conical shape ; the marginal rows of mammillated 
granules on the ambulacra are more numerous, and separated from each other by a double 
series of microscopic granulets ; the apical disc is likewise thicker and more prominent. 

Locality and Stratiyraphical Position. — Collected from the Sponge-gravel of the 
Lower Greensand, near Farringdon, where it was associated with P. Wrightii. It is a 
very rare form in the English Neocomian strata. The fossil figured belongs to the 
British Museum, and is the only English specimen I know. 



150 PELTASTES 

B. Species from the Tipper Greensand. 
Peltastes clathratus, Agassiz. PL XXXII, fig. 1 a—f, 2, 3, 4. 

Parkinson's Organic Remains, vol. iii, pi. i, fig. 13, 1811. 

Salenia clathrata, Agass. MSS. Morris's Catalogue of British Fossils, p. 58, 1843. 

— STELLULATA, Id. Ibid. Ibid. 

— UMBRELLA, Id. Ibid. Ibid. 

— OENATA, Id. Ibid. Ibid. 

— CLATHRATA, Bronti. Index Palseontologicus, p. 1007, 1849. 

UMBRELLA, Id. Ibid., p. 1008. 

— CLATHRATA, Forbes. In Morris's Catalogue of British Fossils, 2nd ed., 

p. 89, 1854. 

— STELLULATA, Id. Ibid. Ibid. 

— UMBRELLA, Id. Ibid. Ibid. 

— CLATHRATA, Woodward. Mem. of Geol. Survey, App. to Decade V, 

p. 6, 1856, 

— — Desor. Synopsis des Echinides Fossiles, p. 151, 1856. 
Peltastes clathratus, Cotteau. Faleontologie Fran9ai8e, terr. Cretace, tome vii, 

p. 119, pi. 1028, fig. 8—18, 1862. 

Diagnosis. — Test siibglobose very convex above, poriferous zones straight, ambulacra 
narrow, straight, with two rows of mammillated granules. Inter-ambulacra wide, three 
pairs of prominent tubercles, miliaiy zone narrow. Apical disc very large, covering nearly 
the entire upper surface, its outline very deeply indented between the ovarial and ocular 
plates, which are smooth, and deeply notched at the sutures ; those connecting the centres 
of the plates forming a distinct pentagon, each of the ovarial pores is the centre of five 
radiating grooves with angular depressions between them. 

Dimensions. — Height nine twentieths of an inch ; six tenths of an inch. 

Description. — This Salenia is a very common species in the Upper Greensand of 
Wiltshire, where it is often found in a fine state of preservation. The test in general is 
small and subglobose, although depressed varieties sometimes occur. It is collected 
likewise from the Grey Chalk near Folkestone, from whence the largest individuals have 
been obtained. In the subglobose forms the upper surface is convex and inflated, and 
the under surface is flat, with rounded sides (PL XXXII, fig. 1 a). The ambulacral 
areas are narrow and very slightly flexed; two rows of small mammillated tubercles, 
fourteen to sixteen in each, set closely together, are placed on the sides of the area (fig. 
1 d), and a line of microscopic granules occupies the centre, and a few are scattered 
between the tubercles (fig. 1 e). The poriferous zones are slightly flexed (fig. 1 d), and 
the holes lie in oblique pairs (fig. 1 e) ; the septum separating each pair has a prominent 
elevation ; and there are eight [)airs of holes opposite the larger plates. 

The inter-ambulacral areas are wide, and the plates in the cohimns unequal in size ; 



. FROM THE UPPER GREENSAND. 157 

there are four or five tubercles in each series, and of these the two uppermost only attain 
a considerable development (fig. 1 b, and fig. 1 d, and fig. 3). The others are much 
smaller, and diminish in size as they approach the peristome (fig. 1 c and fig. 1 d) ; the 
margin of each plate is surrounded by a series of small mammillated granules (fig. 1 <?, 
and fig. 3), which form a circle around the tubercles, and in the upper part of the area 
between the larger granules a number of smaller granulets are placed between tliem 
(fig. I d), thus completing the ornamentation of the miliaiy zone. 

The base of this urchin is flat, and the mouth-opening small (fig. I c) ; the peristome 
is divided into ten nearly equal lobes, by feeble incisions (fig. 1/and fig. 1 c). 

The apical disc is very large, and occupies all the upper surface of the test (fig. 1 b, 
fig. 3). Its ovarial plates are deeply cut, with numerous incisions, which are much better 
defined by figures than words ; faithful portraits of these most complicated impressions 
my friend Mr. Bone has given in fig. 1 b, fig. 2, fig. 3, and fig. 4. These incisions are 
large and deep, and extend through the thickness of the plates ; three deep incisions mark the 
line of suture between the ocular and ovarial plates (fig. 2) ; the two antero-lateral ovarials 
have another series of impressions of a like character before the vent and behind 
the oviductal opening. The oviductal holes are large ; the two anterior are placed 
forward on their respective plates ; the three posterior lie near the inner borders of 
the genital plates and opposite the angles of the periprocte. The ocular plates are heart- 
shaped, and the orbit occupies a depression at the summit of the ambulacra, near the 
extreme border of the plates. The vent is large and transversely oblong, sometimes 
even becoming angular (fig. 1 b). The periprocte is elevated, and its funnel-shaped 
extremity encircled by a bourrelet directed backwards (fig. 3). Most specimens show 
this elevation of the vent, but in many varieties it is not so conspicuous as in the type 
specimen figured in fig. 3, where the test is magnified twice. The spines are long and 
needle-shaped (PL XLII, fig. 4) ; above the milled ring is a broad band of longitudinal 
hues, and the rest of the stem is covered with very fine longitudinal microscopic lines. For 
further details on the spines of this and other species, see description of PL XLII. 

Affinities and Differences. — Peltastes clathratus is readily distinguished from its con- 
geners by its subglobose test, the great size of its apical disc, and the number, width, and 
depth of the numerous incisions that divide its surface ; its flat base and small mouth 
opening, with its rounded sides, present an ensemble of characters which well characterise 
the species and separate it from all the others. 

Locality and Stratigraphical Position. — This species was in former years veiy common 
in the Upper Greensand near Warminster. Small examples were most abundant, and 
large specimens were rare. The largest tests are collected from the Grey Chalk near 
Folkstone ; my kind friend the Rev. T. Wiltshire has obtained several large examples from 
this stratum, and several of these have their spines in situ on the test. 

M. Cotteau gives as the French localities of this species, -where it is very rare, I'fitage 
Cenomanien, Le Havre, Seine-Inferieurc, La Perriere, Orne, Craie a Scaphites. 



158 PELTASTES 



Peltastes umbrella, Agassiz, MSS. PL XXXIV, fig. 1 a — d, fig. 2 and 3. 

Salenia umbrella, Agass. MSS. Morris's Catalogue of British Fossils, p. 58, 18-13. 

— — Id. Forbes, in Morris's Catal. of British Fossils, p. 89, 1854. 

— clatheata, Id. Woodward (pars), Mem. of Geol. Surv., App. to Decade V, 

1856. 

Diagnosis. — Body subglobose, convex above ; apical disc large, covering the upper 
surface, its outline deeply indented between the ovarial and ocular plates, sutural grooves 
deeply and sharply cut, those connecting the centres of the plates fomaing a distinct pen- 
tagon. Each oviductal hole forms a centre, from which five grooves radiate, having angular 
pits between them ; sur-anal plate marked with an inverted triangle formed by horizontal 
and inclined incisions. Ambulacra wide ; two rows of mammillated tubercles crowded 
with granules around the base ; interambulacra with four large tubercles in the upper part, 
and all the others small, diminishing towards the peristome ; base flat, mouth-opening 
small. 

Dimensions. — Height, one quarter of an inch ; latitude half an inch. 

Description. — I have figured the type specimen of this form belonging to the British 
Musemn, as it is the species Prof. Agassiz gave this manuscript name to many years 
ago, when he examined the Cretaceous Urchins in the National Collection. Whether P, 
umbrella is specifically distinct from Peltastes clathratiis I am not in a position to decide. 
The apical disc is certainly much more angularly incised, and more sharply defined than 
in P. dathratm ; and placing two well marked specimens of these type forms in contrast, the 
decision would lie in the affirmative ; but then we have the evidence of M. Cotteau, who 
informs us that the incisions and impressions on the disc alone are not to be relied on as 
specific characters, as one fonu glides into another by a series of intermediate gradations, which 
connect together fonns that appeared when isolated to be very distinct from one another. 

The ambulacral areas are nearly straight, and have two marginal rows of small mam- 
millated tubercles, fourteen in each. The mesial space between the rows and tubercles is 
filled with microscopic granules (fig. 1 c). The poriferous zones are conspicuous, and the 
pores placed in oblique pairs. The inter-ambulacral areas are wide, and the plates in 
the columns unequally developed, those above the ambitus are the widest, and support 
large tubercles ; from the ambitus to the peristome they gradually become smaller, and 
their respective tubercles diminish in the same proportion (fig. 1 b, fig. 1 c, and fig. 2). 

The apical disc is large, and its circumference much indented between the margin of 
the ocular and ovarial plates (fig. 1 a, and fig. 3), presenting two beautiful varieties of this 
remarkable structure. The sur-anal plate situated before the periprocte is marked with 
incisions that form a triangle ; each oviductal hole of the two antero-lateral ovarial plates 
forms a centre, from which five incisions radiate, and from each oviductal hole in the other 
three ovarial plates four incisions radiate outwards, having angular pits between 



FROM THE UPPER GREENS AND. 159 

them. The vent is raised on an eminence which is directed backwards. The anal opening 
is transversely oval, and the periprocte forms a thickened bourrelet, which is oblong in the 
variety fig. 1 a and angular in fig. 3. In both figures the apical disc is magnified four 
^diameters. 

The base of the test is flat, and the mouth opening small, about one third the diameter 
of the test. The specimens figured in figs. 2 and 3 have been kindly communicated by 
W. Cunnington, Esq., F.G.S., as remarkably well marked forms of this species. 

AjfmUies and Differences. — The test of P. umbrella closely resembles that of P. 
dathratus, the difierence chiefly residing in the form and structure of the apical disc, which 
can be much better understood by a comparison of the figures in PI. XXXII, fig. 2, and Pi. 
XXXIV, fig. 1 a, fig. 1 b, fig. 1 d, and fig. 3, and to which we must beg to refer the 
reader. 

Locality and StratigrapMcal Position. — The type specimen was collected from the 
Upper Greensand near Warminster, associated with Peltastes dathratus in the same 
stratum. 

Peltastes Bunburyi, Forbes, sp. PI. XXXIX, fig. 2 a — i. 

Salenia Bunburyi, Forbes. In Morris's Catalogue of British Fossils, p. 89, 1854. 
— — Woodward. Mem. Geol. Surv., App. to Decade V, p. 6, 1856. 

Diagnosis. — Test subglobose, much elevated, sides tumid, base wide and flat ; oral 
aperture depressed ; apical disc large, very deeply indented at the border, between the 
ocular and ovarial plates ; a series of ten elliptical ridges with central depressions fomihig 
an ornamented pentagon on the disc; sur anal plate with two pairs of oblique elliptical 
ridges. Vent large, diamond-shaped, exceutral, looking obliquely backwards, with a 
thickened periprocte. Ambulacra narrow, slightly flexed, with small remote marginal 
tubercles, separated by a prominent ridge of microscopic granules. Inter-ambulacra wide ; 
three prominent tubercles at the ambitus, and four smaller near the base ; upper surface 
covered with scattered granules. 

Dimensions. — Height, half an inch ; transverse diameter, thirteen twentieths. 

Description. — The original and unique specimen of tliis Salenia was presented to the 
Museum of the Royal School of Mines by E. II. Bunbury, Esq., M.P. My late lamented 
colleague Professor Edward Forbes named this Urchin, without leaving any notes of its 
specific characters. A brief diagnosis of these were given by my late friend Dr. Woodward 
in his appendix to the fifth Decade of the Organic Remains in the Memoirs of the 
Geological Survey. It is now figured for the first time. 

The test is svdiglobose and much elevated (fig. 2 a — d), inclining to a conical form. 
The andjulacral areas are narrow, and slightly flexed with two rows of small remote 
marginal tubercles, sixteen or seventeen in each row. These are separated by a median 
ridge formed of microscopic granules, which fill up all the space unoccupied by the tubercles. 



160 PELTASTES 

The poriferous zones are naiTow, the pores small and placed in oblique pairs, of which 
there are forty in each zone. The septa between the pores are capped by a prominent 
granule. 

The inter-arabulacral areas are wide, and the plates in the columns of unequal size. 
There are three large tubercles in each area ; of these one is very large, and two mode- 
rately so ; the five others diminish gradually towards the peristome ; the upper surface is 
destitute of tubercles, and this vacant space is covered with small, various sized, sparsely 
scattered, niaramillated tubercles ; a series of these encircle the areolas of the primary 
tubercles. Fig. 2/ represents an inter-ambulacral area, magnified four diameters, 
showing the great disparity existing between the volume of the different tubercles deve- 
loped therein. The miliary zone is likewise ornamented with similar bodies. Fig. 2 h 
displays these parts, magnified six times, in a single plate, and fig. 2 « a tubercle seen 
in profile. 

The base is wide and flat, and highly ornamented with the small close-set tubercles 
of the inter-ambulacral areas. The oral aperture, one third the diameter of the test, lies 
in a depression (fig. 2 c). The peristome is divided into ten lobes by feeble incisions. 

The apical disc occupies a large portion of the upper surface ; its border is exceed- 
ingly sinuous, and deeply incised at the marginal boundary line between the ocular and 
ovarial plates ; from each oviductal hole two pairs of elliptical-shaped incisions proceed, 
and right and left to join those proceeding from the adjoining oviduct ; and these form 
the sides of the pentagon which extends around the disc. The sur-anal plate is marked 
by two pairs of elliptical incisions, which join those from the anterior ocular, and thus 
form a diamond-shaped impression before the vent (fig. 2 c). The ovarial plates termi- 
nate in three-lobed cardiform expansions, and from each side of the orbits similar heart- 
shaped trilobate bodies stretch obliquely outwards. The disc of this species forms a 
most complicated structure, of which words fail to give any adequate idea. Fortunately, 
my friend Mr. Bones' admirable figures supply the eye with the fine symmetrical propor- 
tions of this intricate bit of anatomy. Consult fig. 2 a, b, d, e, for all details. 

The vent is large and looks obliquely backwards ; it is of a diamond shape, with a 
thick prominent periprocte ; at the three posterior angles of this bourrelet the single and 
postero-lateral oviducts open, the two antero-laterals are placed much in advance on the 
lateral boundary of the sur-anal. 

Affinities mid Differences. — The sculpture of the apical disc and the deep incisions 
through the same reminds us of some forms of Peliastes clathratus ; the margin, however, 
is more deeply indented, and the style of ornamentation on the same is different ; the 
marginal tubercles on the ambulacra are smaller and more remote, and divided by a 
prominent granulated ridge ; the structure of the inter-ambulacra exhibits a considerable 
diflerence, and the pores in the zones are smaller and more numerous. 

Locality and Strafip-apMcal Position. — This rare Salenia was collected from the 
Lower Chalk, Mildenhall, near Bury St. Edmunds. The original and unique specimen 
is in the Museum of the Royal School of Mines. 



THE 



PAL/EONTOGRAPHICAL SOCIETY. 



INSTITUTED MDCCCXLVII. 



VOLUME FOE 1872. 




LONDON 

MDCCCLXXII. 



MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODERMATA 



FROM 



THE CRETACEOUS FORMATIONS. 



BY 



THOMAS WRIGHT, M.D., F.R.S. Edin., F.G.S., 

COKKESPONDING MEMBER OF THE ROYAL SOCIETY OF SCIENCES OF LIEGE, THE SOCIETY OF 

NATURAL SCIENCES OF NEUFCHATEL, AND SENIOR SURGEON TO 

THE CHELTENHAM HOSPITAL. 



VOLUME FIRST. 
PART FIFTH. 

ON THE SALENIDtE. 

Pages 161—184 ; Plates XL— XLIV. 



LONDON: 

PRINTED FOR THE PAL^EONTOGRAFHICAL SOCIETY. 

1872. 



PBINTED BT 
J. E. ADLARD, BABTHOLOMEW CLOSE. 



FROM THE RED CHALK. 161 



Peltastes Wiltshirei, Wri(jht, nov. sp. PI. XL, fig. 1 a — h. 

Biagnosis. — Test subglobose, elevated at the upper surface, flat at the base ; ambulacra 
narrow, straight, two rows of marginal mammillated granules ; poriferous zones narrow, 
and slightly flexed ; inter-ambulacra wide, two rows of large tubercles, five in each ; apical 
disc very broad, margin deeply cut out ; ovarial plates largely incised ; vent elevated j 
periprocte prominent, projecting outwards and backwards. 

Dimensions. — Altitude, six tenths of an inch ; latitude, eight tenths of an inch. 

Description. — We owe the discovery of this beautifid Peltasfes to the long, careful, and 
patient study of my excellent friend, the Rev. T. Wiltshire, F.G.S., on the red chalk of 
England, to whose valuable collection it belongs. The test is subglobose, much elevated 
on the upper surface, and covered with a very large apical disc ; the base is flat, and the 
sides are tumid. The ambulacral areas, very narrow and straight, are occupied by 
two rows of small oblong mammillated marginal granules, about nineteen in each row, 
separated by a narrow band of fine, close-set granulations, which extends from the base to 
the summit of the area ; the poriferous zones are narrow and slightly flexed, and the 
small pores are arranged in oblique pairs, of which there are thirty-eight in each zone. 
Eig. l/exhibits one entire ambulacrum, with its poriferous zones, magnified four diameters. 

The inter-ambulacral areas are wide and largely developed (fig. 1 a, d, c) ; the ovarial 
and ocular plates of the apical disc cover up much of the upper portion (fig. 1 b, d, e) ; 
there are ten primary tubercles in each area, of which four are very large, two small, and 
four smaller ; they are all surrounded by wide areolas (fig. 1 d, e), and around their 
margins a few large granules are sparsely disposed, about five around the largest plates, 
three at the central, and two at the zonal side of the plate, as shown in fig. 1 h. The 
base is flat (fig. 1 c), about two fifths the diameter of the disc, the mouth-opening is 
nearly one half the diameter of the test, and the peristome is divided into ten nearly 
equal lobes by deep incisions ; the numerous small tubercles at the base of the areas, and 
the larger size of the marginal ambulacral granules, impart to this region of the test a 
highly ornamented appearance (fig. 1 c). 

The apical disc (fig. 1 b and ^7) is a large and complicated structure ; the suranal plate lies 
in front of the vent, and is notched with sections of four elliptical impressions ; the ovarial 
plates are large and cut in a hke manner into similar patterns, the two adjoining plates 
contributing each one half of the ellipse, so that the sculptured pattern on the entire disc 
is made up of separate pieces like mosaic ; the oviductal holes are in the middle of the 
plates and on the right antero-lateral ; the madreporiform tubercle appears like a laceration 
on the inner side of the oviductal hole — this has unfortunately escaped the eye of our 
artist, as it looks more like a portion of decayed plate than a veritable natural structure. 
The ocular plates are likewise large, and have five or six notches round their border, which 
in like manner join similar notches on the ovarial plates and complete the elliptical pattern 

21 



162 PELTASTES 

of the sculpture of the disc ; the outer border of each ocular plate forms a crescent around 
the summit of the ambulacra, and the terminal portions of the ovarial plates form an elegant 
five-leafed petal extending down the middle of the inter-ambulacra ; the outer margin 
of the disc is therefore very deeply incised between the ovarial and ocular plates, and 
produces a structure which will be better understood by an examination of fig. 1 g, mag- 
nified four diameters, than by any verbal description. The vent is large and the periprocte 
bluntly diagonal, angular at the sides, and less convex before than behind (fig. 1 g) ; when 
viewed in profile, as in fig. 1 a and d, the apical disc is conspicuously prominent, and the 
elevated periprocte is seen to be very excentral and projected far backwards. 

Afinities and Differences. — This beautiful species in its general characters resembles 
Scdenia Austeni, Forbes ; but a careful comparison of the tests of both species discloses 
important differences ; the ambulacra in P. Wiltshirei are narrower, with only two rows of 
oblong marginal granules throughout, whilst S. Austeni has four rows in its wider 
ambulacra. The inter-ambulacral areas in P. Wiltshirei are wider, and the primary 
tubercles therein fewer and larger than in S. Austeni. The apical disc of P. Wiltshirei 
is much larger ; the marginal incisions are deeper, the lines of sculpture wider, and the 
periprocte is in the axis of the suranal plate. 

This species resembles P. Bunbiiryi, Forb., in the general structure of the test, and of 
the apical disc ; the inter-ambulacral areas in P. Wiltshirei are wider, the tubercles are 
larger and more regular, the apical disc covers a wider surface of the test than in P. 
Bunburgi, and is deeply sculptured after a different pattern, both around the margin and 
along the sutures of the plates. 

Locality and Stratigraphical Position. — llhi?, Peltastes is a very rare Urchin in the Red 
Chalk of Hunstanton Cliff, Norfolk, where it was found by the Rev. T. Wiltshire, F.G.S., 
who has contributed a valuable paper on this stratum to the ' Quarterly Journal of the 
Geological Society,'^ and from which I have made the following quotations, as the true 
position of the Red Chalk is well defined in that communication. 1 am indebted to the 
kindness of the Council of the Geological Society for the use of the annexed woodcut 
illustrating the stratigraphy of this locality. 

Hunstanton Cliff " is marked by three parallel coloured bands, slightly inclined, and 
cropping out in succession on the surface soil, of which bands the uppermost is white, the 
next bright red, and the lowest yellow, each division being sharply defined, without any 
intermingling of tints at the line of contact. . . . The highest stratum, the white, con- 
sists of a hard calcareous substance, compact in texture, and much shattered and fissured, 
originally deposited in such a manner that its materials were arranged in definite layers, 
two of which {a b), those forming the base, are represented in the annexed section drawn 
to scale. The first of these (a), in thickness about 2 feet 6 inches, is noticeable for the 
presence of an enormous quantity of fragments of Inocerami dispersed throughout its 

' 'Quart. Journ. Geol. Soc.,' vol. xxv, p. 185, 1869. 



FROM THE RED CHALK. 



163 



Section of Hunstanton Cliff. 



whole extent, and which under the influence of weathering impart to this portion of the 
diff a jagged and rough appearance. Its characteristic fossils are spines of Cidaris vesi- 
culosa, Holaster planus, Vermicularia umbonata, Tere- 
bratulina gracilis, Terebratula semiglobosa, and Plica- 
tula inflata. The band h, in thickness about 1 foot 2 
inches, is conspicuous for a meandering and many- 
branched Sponge {Syphonia paradoxica), specimens of 
which are visible in the cliff only in short lengths, but 
on the fallen blocks washed by the sea are seen to 
extend continuously and horizontally over many square 
feet of surface. The underside of b departs from the 
general arrangement in the other courses ; for its base, 
instead of forming a flat or approximately flat floor, is 
broken up into a series of irregularly rounded ridges 
and hollows, which undulate perpendicularly within the 
limits of a few inches, and are represented in the section. 
The fossils from this bed {b) are not so many (numeri- 
cally speaking) as those in a. The chief forms are 
8ipho)iia paradoxica, Terebrafida biplicata, Terebratula 
semifflobosa,'^av. undata, Kingena lima, Avicula grgphmoides, 
and Inoceramus latus. 

" Next in succession, in descending order, is the red 
stratum, locally called the 'Red Chalk,' marked by an 
abundance of organic remains, some of Avhich, as 
Bourgiieficrinus rugosus and Terebratula cupillata, are, 
in England, special to this deposit. Lithologically it 
is unlike the beds above it, from the fact of its abound- 
ing in great numbers of rolled and subangular pebbles 
of quartz, slate, &c., which for the most part are of small 
size and insignificant, though occasionally assuming 
larger dimensions. In appearance it is divisible into 
three almost equal portions, of which the first (a) has towards its base a large 
quantity of fragments of Inocerami, the second and thickest division (b) is rich in 
Belemnites, and the third and lowest (c) yields many Terebratulce. The bands a and b 
are exceedingly hard and stony, and sufficiently tabular in character to have off'ered a 
plane of resistance to former upheaving forces, and to have aff'orded great support to the 
overlying white beds ; thus, although the whole cliff was evidently, in ancient geological 
times, much disturbed, the perpendicular fissures which rise out of the yellow bands 




* A thickness of upwards of 30 feet is here omitted for convenience. 



164 PELTASTES 

(y, x) cease just before reaching the layer b, affect the i^ed beds to the right and left of 
the points of application, and then start upwards through the white stratum in new posi- 
tions and in greater number. The colouring matter in a is less equally distributed than 
in B and c, and seems to have been accumulated as an envelope around irregular spheroidal 
masses ; in b the tint is of a lighter, and in c of a darker shade than in the highest 
division. The middle bed (b) is in substance the hardest and most homogeneous of the 
three ; the last (c) is the least compact. Viewed in the cliff, a wears a mottled aspect, b 
a nodular facies, and c a plain surface. Towards the base of the bottom bed (c) the hard 
limestone character of the Red Chalk is lost, and the stratum degenerates into a some- 
what sandy incoherent mass, hardly differing from the underlying, yellow division, except 
in colour. On account of the less compact nature of the last of the three red beds, fossils 
are more easily procured from it, have their surfaces in better condition, and are more 
readily seen when of small size. Resting on the top of a and filling the undulations on 
the under side of the lowest white bed {d) is a bright red argillaceous substance, very 
friable, without sand, apparently destitute of organic remains, and never exceeding two 
or three inches in thickness. 

" The fossils in the three red beds are for the most part similar, and suggest the infer- 
ence that all three bands may be considered as forming a single division, and composing 
one geological stratum. In the case where certain fossils have been seen only in the 
lowest part, their absence elsewhere may be accounted for on the ground that the upper 
bed (a) is less numerically abundant in organic remains than are those below, and that 
the middle bed (b) is so exceedingly hard and compact as to diminish the chance of 
discovering fossds. Avicida (jrypliaoides and Spongia jjcradoxica would seem, however, 
to be special to the upper part of a, the highest of the three red beds. The dip of these 
beds in the cliff is about 2° to the north ; sections inland, taken at right angles, give the 
same number of degrees to the east. 

" Underlying the Red Chalk is a coarse sandy deposit (x, t of the Section) termed 
in the district ' Carstone,' of a yellow tint, loose in composition, and full of small pebbles, 
which are subangular and polished. The upper part (x), for about 8 feet, consists of 
much sand, and is succeeded by a dark brown stratum (y), in which, at the beginning, 
the pebbles are of larger size, and in which, afterwards, the sandy particles are so 
loosely held together as to present a strong contrast to the massive nature of the white 
and red beds above. Covered by the Carstone and adjoining it is a bed of clay marked 
z in the section. 

" Throughout the space of more than thirty feet below the base of the Red Chalk no 
fossils have been hitherto found at Hunstanton in the Carstone; but beyond that distance, 
and just above the clay (z), there is a line of nodules (j/), in which are numerous speci- 
mens oi Ammonites Deshayesi, and occasionally of ^. Cornuelianus ; close to these nodules 
are others of ironstone, very similar to the masses found in the Lower Greensand of 
Blackgang and Shanklin, in the Isle of Wight, containing casts of fossils. 



FROM THE RED CHALK. 16£ 

" From this part of the Carstone I have obtained Perna Mulleti, Ancyloceras (jigas, 
Pleuroiomaria gigantea — fossils which, viewed in connection with the presence of Ammo- 
nites Deshayesi, &c., correlate the portion of the Carstone iuamediately above the clay (z) 
with the base of the English Lower Greeusand. 

" By a reference to the section it will be seen that the Hunstanton Red Chalk is, in 
position, lower than the Chalk-marl («), and higher than the Lower Greensand (x, y) ; 
the fossils also, it will be observed, recorded in the list as common to the bed, present a 
mixture of what are generally considered Lower Chalk, Upper Greensand, and Gault 
forms. The mingling together of these species, no less than the peculiar aspect of the 
stratum, has long caused the Red Chalk to be a fertile field for discussion in reference to 
its proper position in the geological scale, various writers ofiering various opinions, Mr, 
C. B. Rose^ inclining to its being the equivalent of the Gault, Mr. H. Seeley" to its being 
Upper Greensand, and Mr. Judd' to its combining both formations. If, however, the 
very fine section of the Gault at Folkstone (where the succession of the beds and their 
fossils can be examined in situ) be taken as typical of the English Gault, then it will 
become evident that the ' Red Chalk ' is the representative of the upper division of that 
formation." 



Genus — Goniophorus, Jgassiz, 1838. 
GoNioPHORUs, Desor. Goniophorus, Cotteuu. 

Test small, circular, elevated above, and flat beneath. Interambulacral areas wide, two 
rows of large tubercles with well-developed areolae, crenulated bosses and imperforate 
mammelons ; pores small, simple, unigeminal. Ambulacral areas very narrow, and having 
the poriferous zones slightly undulated. 

jMouth-opening small, peristome decagonal, with nearly equal sized oral lobes. 

Apical disc smooth, prominent, regularly pentagonal, and moderately large, composed 
of five ovarial and five ocular plates, and one suranal placed before the vent, which is 
excentral, in the axis of the body, and placed a little backwards, as m the genus Peltastes. 
The disc is destitute of sutural impressions so characteristic of many Salenid^, and is 
ornamented with prominent carinse, which assume regular geometrical figures, altogether 
independent of the form of the ovarial plates or their connecting sutures ; in fact, it is 

' "On the Geology of West Norfolk," ' Phil. Mag.,' 1835, vol. vii, p. 180. 

- "Notice of Opiuions ou the Stratigraphical Position of the Red Limestone," 'Ann. Mag. Nat. Hist.,' 
1861, vol. vii, p. 240. 

3 "Strata which form the base of the Lincolnshire Wolds," 'Quart. Journ. Geo). Soc.,' vol. xxii, 
p. 249, 1867. 



166 GONIOPIIORUS 

the carinated structure, superadded to the surface of the disc, which forms one of the most 
distinctive characters of this group. 

The genus Goniophorus resembles Peltnstes in the arrangement of the elements of the 
apical disc and the relative position of the periprocte to the axis of the body. It is distin- 
guished from it, however, in the absence of sutural impressions, and the presence of 
prominent ribs, that divide the smface of the pentagonal disc into a number of 
triangular areas (PI. XXXVI, figs. 1 and 2). 

M. Cotteau^ has added another character, which he considers of more importance than 
the preceding ; and observes, " The structure of the ambulacra presents a difference 
much more important, and the existence of poriferous impressions at the base of some of 
its granules form a type certainly exceptional, which ought to have a place apart in the 
Family Salenid.^. This character has not hitherto been noticed in any other Echinid." 



Goniophorus lunulatus, Jf/assiz, 183S. PI. XXXVI, fig. 1 a — d, fig. 2 a — d. 

GoNioPHORts LLXULATUS, Affitssh. Monogr. des Salenies, p. 30, pi. v, figs. 1" — 2-1, 

1838. 

— APICUL.VTUS, Agassi-. Ibid., p. 32, pi. v, figs. 25 — 32, 1838. 

— — Jgassiz. Catal. Ectyp. Foss., p. ii, 1840. 

— FAVOSUS, Agassi:, MS. Morris's Catal. of British Fossils, p. 52, 

1843. 

— LUNULATUS, Morris. Catalogue of British Fossils, p. 52, 1843. 

— — Agassis et Besor. Catal. raison. des Ecliiiiides, Aim. des 

Sc. Nat., 3e serie, t. vi, p. 343, 1846. 

— APICULATUS, Agassi: et Besor. Ibid. 

— — Bronn. Index Paleeontol., p. 548, 1849. 

— FAVOSUS, Biohii. Ibid. 

— LUNULATUS, Bronn. Ibid. 

— — B'Orbigmj. Prod, de Pal. strat., t. ii, p. 179, 1850. 

— APICULATUS, B'Orbigmj. Ibid. 

— F.Yvoscs, B'Archiac. Hist, des Progr. de la GeoL, t. iv, p. 51, 1851. 

— LUNULATUS, Bromi. Lethsea geogn., t. ii, p. 184, pi. xxix, fig. 6, 1852. 
Salenia lunulata, Morris. Catal. of Brit. Foss., 2 ed., p. 89, 1854. 
GoNioPHOKUs APicuL.^TUs, Besur. Synopsis des Echinides Foss., p. 14, pi. xx, 

fig. 12, 1856. 

— LUNULATUS, Pictet. Traite de Paleontol., t. iv, p. 248, 1857. 

— APICULATUS, Pictet. Ibid., pi. xcvii, fig. 3, 1857. 

— LUNULATUS, Cotteau. Paleontol. FranCj-aise, t. vii, pi. 1029, figs. 8— 19, 

1864. 



' ' Pak'oiitologie Frangaise,' t. vii, p. 1'26, Terrain cretace. 



FROM THE UPPER GREENSAND. ~ 167 

Diapwsis.- — Test small, globular, upper surface elevated, summit depressed, base flat, 
sides rounded ; ambulacra narrow, slightly flexed, filled with two rows of granules ; inter- 
ambulacra wide, two rows, six in each, of weU-developed tubercles ; apical disc small, 
angular, and pentagonal ; diagonal ridges of shell marking the surface of the plates ; base 
narrow, concave ; mouth-opening small, peristome decagonal with equal lobes. 

Dimensions.- — -a. The largest specimen, fig. \a, altitude half an inch; latitude six 
tenths of an inch. 

B. Altitude, three lines ; latitude, five lines. 

c. Altitude, two and a half lines ; latitude, three and a half lines. 

Description. — This beautiful little Urchin, the sole representative of the genus 
Goniophori/s, was at one time not uncommon in the Upper Greensand, near Warminster, 
and it is curious that no second species of the remarkable group to which it belongs has 
up to the present time been discovered ; the two other forms which appear in the table 
of synonyms {G. apiculatiis, G. favosus) being only usual varieties of the original type, 
so beautifully and accurately figured by M. Nicolet in Professor Agassiz's ' Monographies 
d'Bchinodermes,' where it was for the first time described. 

The test is small and nearly globular, the upper surface much elevated, the summit 
a little depressed, the sides inflated, and the base narrow and flat. The ambulacral 
areas are very contracted, and slightly flexed (fig. 2 b), the two rows of granules are set so 
closely together that they alternate on the area ; the poriferous zones are nearly as wide as 
the ambulacra, the pores are oblique, and the pairs remote from each other, twenty-four in 
the zone. The inter-ambulacral areas are well developed (fig. 2 a) ; in the specimen, fig. 
1 a, there are six primary tubercles in each row, the four above the ambitus are much 
larger than those on the lower part of the area, and the areola of each tubercle is sur- 
rounded by a complete circle of small mamraillated tubercles (fig. 1 a, d, and fig. % a, c) ; 
the miliary zone separating the two series is narrow and zig-zag, and only a little 
enlarged at the upper surface (fig. 1 d, fig. 2 a). 

The base is narrow and concave, and the small mouth-opening, one third the diameter 
of the test, lies in a central depression ; the peristome is divided by feeble incisions into ten 
equal-sized lobes (fig. 1 c). 

The apical disc (fig. 1 b, d) forms a regular pentagon, ornamented with prominent 
ridges ; an external carina bounds the outline of the disc, an oval carina encircles the vent, 
and two others extend from the anterior part of the periprocte to the two anterior sides of 
the discal pentagon (fig. 2 d), and two others unite these with the sides of the vent (fig. 1 b) ; 
these ridges of ornamentation have nothing whatever to do with the sutures of the disc, 
which are very delicate, and only seen in some rare specimens ; these sutures in Gonio- 
phorus are destitute of the incisions, punctuations, and impressions which form so 
remarkable a feature in the test of Peltastes. 

The suranal plate lies before the periprocte, having the two anterior carinse passing 
from the periprocte to the anterior border extended over its surface ; the two antero-lateral 



168 GONIOPHORUS 

ovarials have a rliomboidal figure, the postero-laterals an irregular shape, occasioned 
by the lateral extension of the vent, and the single plate is still longer and narrower by 
reason of the space occupied by the same aperture ; the oviductal holes occupy the centres 
of the sides of the pentagon near the point touched by the diagonal carinse that cross the 
ovarial plates. The ocular plates form small triangular bodies, the apices of which touch 
the summits of the ambulacra (fig. 2 b) ; in neither of the fine specimens from Mr. 
Cunningham's collection, nor in those from the School of Mines, which were selected as the 
best extant for figuring, could the sutures of the ovarial and ocular plates be seen. I have 
only discovered them now, April, 1871, long after the drawings were executed.in an otherwise 
indifferent specimen of my own, collected many years ago, and I have been able therefrom 
to trace out these sutural lines satisfactorily, and complete my description of the apical 
disc of this most curious and beautiful Salenia. The vent is transversely oblong, inclining 
to an angular figure, and surrounded by a ridge of the test, which well defines its 
boundary, and forms a prominent periprocte at the same time. The carinse of the disc 
cross the sutures of the plates in all directions, especially those anterior to the periprocte, 
and convert its surface into a series of seven triangles when all the ridges are preserved 
entire. 

Affinities and Differences. — This Urchin is so entirely different from other Salenid^ 
in the structure of its apical disc that it forms a type quite distinct from all the others ; 
the calcareous processes or carinse on the surface of the ovarial and ocular i)lates have 
nothing whatever to do with the sutural fines which unite the elements of the discal 
apparatus, whereas in Peltastes and Salenia the figures on the disc are always developed 
in the line of the sutures. 

Locality and Stratigrapldcal Position. — This Urchin has been collected from the 
Upper Greensand near Warminster; on the Continent it is a very rare fossil. The 
original specimen was found in the Etage Cenomanien, at Cap la Heve, near Havre, Seine 
Inferieure ; others from the same stratum at Vaches Noires, Calvados, and Vimoutiers, 
Orne ; in all these localities it is reported as being very rare. 

History.— Yix%i described and figured by Professor Agassiz in his ' Monographic sur 
les Salenies.' In this work he described two forms as distinct species, G. lunulatus 
and G. apicidatiis, which I consider as varieties only of the same Urchin. Professor 
Agassiz afterwards gave the MS. name G. favosus to a form of this group which 
he saw in the collection of Mr. Bunbury, of London, and the name found its way into 
Professor Morris's ' Catalogue of British Fossils,' 1 st Edition ; this variety exhibits only 
a slight deviation from the type form, so that the singular genus GoniojAorus is at 
present represented by the beautiful little Urchin now under consideration. Seeino- 
that so many examples of Salenid.e have been collected from the Upper Greensand of 
England, and the Cenoraanian stage of France, during the last forty years, it is remarkable 
that no true second species has been found. It has often occurred to me that this is 
one of many problems of a like nature that the disciples of Darwin might attempt to 



FROM THE UPPER GREENSAND. 169 

solve. The geological record of the Cretaceous rocks where the Salenid^ ■ abound 
is not so imperfect as many assert, and connecting forms, if such ever really existed, 
ought to be found somewhere in beds that are so often searched and so diligently worked 
for the Palgeontological treasures they contain. Notwithstanding all this investigation, 
Goniopliorus lunulatus still remains an isolated genus represented by a single species 
among the Salenid^. 



Genus — Salenia, Gray, 1835. 
Salekia, Affassiz, 1838. Salenia, Desor, 1858. Salenia, Cotteau, 1864. 

Test small, circular, moderately elevated, sides inflated, more or less convex above and 
flat beneath ; poriferous zones narrow, pores unigeminal, simple in the zones, and crowded 
near the peristome ; ambulacral areas narrow, gently flexuous, with two or four rows of 
close-set homogeneous mammillated granules. Inter-ambulacral areas wide, with two 
rows of large crenulated imperforate tubercles. 

Mouth-opening nearly two thirds the diameter of the test ; peristome divided into ten 
unequal lobes by feeble incisions ; vent circular, periprocte elevated, excentral, and 
posterior, placed at the right side of the axial line of the body ; apical disc shield-shaped, 
covering a large portion of the dorsal surface ; plates prominent, with a deeply undulated 
border ; the ovarials and suranal large and pentagonal, the ocidars wide and cordate ; the 
sutures punctuated or incised, and the surface of the plates smooth in S. pefal/fera, 
sometimes granulated, in S. granulosa, or striated with geometrical lines forming various 
figures, as in 8. Clarkii and S. Austeni. 

The right antero-lateral ovarial plate exhibits a slight laceration, in which the madre- 
poriform body is sometimes seen in ^v•ell-preserved specimens ; often it is iuvisible. 

The spines are known only in a few species ; in some they are long, slender, and 
aciculate ; in others they are stronger, with spatulate terminations (PI. XXXVIII, fig. 2) ; 
some rarer specimens have their stems flexed, and others have the extremities bent to right 
angles with the stem (PL XXXVIII, fig. 3 ; PI. XLII, figs. 1, 2, 3, 4, 5). 

The genus Salenia is distinguished from Heterosalenia and Pseudosalenia by its 
imperforate tubercles, and from Pel tastes, which it very much resembles, by the position 
of the vent. In Salenia the periprocte opens excentrically on the right side of a line passing 
through the axis of the body, whilst in Peltastes the periprocte lies in the centre of such 
an axial prolongation. 



22 



170 



SALENIA 



A. — Species from the Uiiper Greensand. 
Salenia PETALiFERA, Desviarest, sp., 1825. PI. XXXIII; PI. XLII, fig. 3. 



EcHlNlTE, from Wiltshire, Parkinson. Organic Remains, vol. iii, pi. i, fin;. 12, 181 I. 



Echinus, 



AREOLATUS, 
PETALIFERUS, 



Salenia petalifera, 



PERSONATA, 



PETALIFERA, 
PERSONATA, 



— PETALIFERA, 

PERSONATA, 

— PETALIFERA, 

— PERSONATA, 

PETALIFERA, 



JV. Smith. Strata identified by Organized Fossils, p. 1 2, 

Greensand, fig. ii, 1816. 
Koniy. Icones foss. sectiles, fig. 100, 1820. 
Besmarest. Oursin ; Diet. Sc. Nat., t. xx.'cvii, p. 101, 1825. 
Be Blainville. Zoophytes, Ibid., t. It, p. 210, 1830. 
Desmoiilins. Etndes sur les Echinides, p. 302, 1837. 
Agassi:. Monogr. des Salenies, p. 9, pi. i, figs. 1 7 — 2-1, 1838. 
Agassiz. Catal. Ectyp. foss., p. II, 1840. 
Bujardin. [n Lamarck's Animau.t sans Vert., 2e ed., t. iii, 

p. 394, 1840. 
Morris. Catalogue of British Fossils, p. 58, 1843. 
Agassi: et Besor. Catal. rais. des Echinides, .\n\^. Sc. Nat., 

3e serie, t. vi, p. 341, 184G. 
Forbes. Jlem. of Geol. Surv., Decade I, pi. v, 1849. 
Bronn. Index Palaeontologicus, p. 1107, 1849. 
d'Orbigny. Prodrome de Pal. strat., t. ii, p. 179, 1850. 
d'Orhujny. Cours element, de Pal., t. ii, p. 126, fig. 277, 

1851. 
Bronn. Lethsea Geog. Kreide-Geb., pi. xxix, fig. 15, 1852. 
John Mailer. TJeber den Bau der Echinodermen, p. 7, pi. i, 

fig. 15, 1854. 
Forbes. In Morris's Catal. of Brit. Fojs., p. 89, 1854. 
Besor. Synopsis des Echinides foss., p. 149, pi. sx, 

figs. 1—3, 1856. 
Pictet. Traite de Paleontologie, t. iv, p. 247, pi. xcvii, 

fig. 1, 1857. 
Cotleau. Paleontologie Francaise, Terrain cretace, tom, vii, 

p. 144, pi. 1034, 1864. 



LiatjHosis. — Test circular, depressed, upper surface conve.\, sides inflated, base 
narrow, concave; ambulacra wide, prominent, fle.xed, two complete rows of large marginal, 
and two incomplete rows of small central granules. Inter- ambulacra tliree times the 
width of ambulacra, two rows of tubercles, six in each, large above the ambitus, small 
below ; miliary zone wide, sparsely granulated ; apical disc smooth, large, margin 
undidated, sutures marked with punctuations ; vent circular, periprocte thin and 
prominent. 

Dimensions. — Altitude, four tenths of an inchj latitude, seven tenths of an inch. 



FROM THE UPPER GREENSAND. 171 

Description. — This beautiful Urchin, so long known to collectors of Upper Greensand 
fossils, has a subglobose body, depressed above, flat below, and with inflated sides ; the 
ambulacral areas, gently flexed, stand out more prominently than the inter-ambulacrals ; 
they have two complete rows of larger granules on the margins of the area, and two 
incomplete rows of smaller ones within (fig. 1 c, d, and fig. 2 h) ; the poriferous zones are 
very narrow, depressed, and much flexed, and the pores, which are unigeminal throughout 
(fig. 1 f/), are arranged in oblicioe pairs, separated by a prominent tubercle on the septum 
(fig. 2 h). The inter-ambulacral spaces are three times as wide as the ambulacral, with 
two rows of tubercles, having six in each row, those above the ambitus are large and well 
developed (fig. 1 b, d), those below are small, and decrease nuich in size as they 
approach the peristome (fig. 2 a) ; the base acquires an ornamented appearance from 
the number of small primary tubercles that adorn it (fig. 2 a). Each tubercle is sur- 
rounded by a wide areola, around which a more or less complete circle of large granules 
is regularly arranged (fig. 1 d), and most of these granules are mammillated; the miliary 
zone is wide below, and increases in diameter above ; throughout it is covered with small 
granules nearly of the same size (fig. 1 c andf/). At the base of the area the primary 
tubercles and granules are disposed as in fig. 3, where a portion of the area is magnified 
six times ; and a profile of one tubercle is given in fig. 4, magnified four times. 

The base is flat, and concave towards the centre, the mouth-opening, one third the 
diameter of the test, is sunk in a depression ; the peristome is deeply incised, and divided 
into ten nearly equal-sized lobes (fig. 2 a, fig. 4 (5). 

The apical disc forms a very regular structure in this species ; the antero-lateral and 
postero-lateral ovarial plates have a rhomboidal figure, and the single or suranal plate is 
smaller in consequence of the position of the vent ; the oviductal holes are perforated near 
the centre of the plates ; and the madreporiform body is seen as a slight laceration on the 
surface of the right antero-lateral in some well-preserved specimens only. The ocular 
plates are much smaller, and transversely or subtriangularly oblong, their inner sides 
forming the prominent portions of the triangle, and their frontal margins the bases. The 
suranal plate occupies the centre of the disc before the vent ; it is nearly as large, and of the 
same form as one of the ovarials, and the lines of the sutures present many punctuations. 
At the angles of junction of every three plates is a deep punctuation, and another in the 
line of union between every two plates. Thus there are nine punctuations around the 
borders of the three anterior ovarials, six around each of the posterior ovarials, and three 
around the oculars (fig. 1 e, b). The pits at the junction of three plates are triangular, 
and those at the junction of two circular ; they are never prolonged as linear notches into 
the substance of the plates, as in Pdlastcs dathralus and P. Bunhuryi. The vent is 
subcircular, excentral, and inclines to the right side ; the periprocte is elevated and pro- 
minent, and bordered by a rim formed of the elevated margins of the suranal, right 
postero-lateral, and single ovarial plates. There is considerable variation in the size of 
the punctuations and the width of the lines of suture ; but these variations have all their 



172 SALENIA 

connecting links, and fall within the general description given of the punctuations on the 
sutural lines of the discal elements. 

Affinities and Differences. — Salenia petalifera forms an excellent type of the true 
Salenia, and a leading fossil of the beds in which it is contained. I cannot appreciate 
the differences which some naturalists point out between this species and S. scutigera, 
Miinster ; and as I have never seen a true type of that species, I must reserve my 
opinion until I can make a comparison between them. After many careful examinations 
of Herr Hohe's figure in the ' Petrefacta,' and knowing the extreme accuracy and truth- 
fulness of that excellent artist's admirable drawing, I am inclined to think that Cidarites 
scutiger, Miinster, is only a smaller form of S. ])etalifera, Desm. ; but as most competent 
authorities have ruled it otherwise, I have not put 8. scutigera in my list of synonyms. 

8. petalifera resembles 8. Austeni, Forb. ; the latter, however, has a more elevated test 
with a smaller apical disc, and more prominent periprocte. It very much resembles 
8alenia giblia, from the same stratum of Upper Greensand, which may Ije only a variety 
of 8. petalifera : a closer comparison between these two allied forms will be found in the 
description of 8. gihha. 

Locality and 8tratigraphical Position. — 8ulenia petalifera was at one time an abundant 
fossil in the Upper Greensand of Longleat, Wilts ; but has now become more rare. It is 
collected from the Grey Chalk near Folkestone, where some very fine examples are some- 
times obtained. I have long noticed that nearly all the Upper Greensand Echinidse 
are found in the Grey Chalk, and that the specimens from the latter stratum are in general 
larger and more fully developed, as if they had been better nourished, than those collected 
from the arenaceous beds of the Upper Greensand of Wilts and other localities. 

History. — This Urchin has long been considered to be a leading English fossil of the 
Upper Greensand ; and Parkinson, 1811, Smith, 1816, Konig, 1820, have all given good 
figures of this Echinite. 

Foreign Distribution. — In the Craie Chloritee de Cap-la-Heve, and other parts of 
France, in Bavaria and Minorca, and in the " Hils-Congloraerat " of North Germany. 



Salenia Loriolii, Wright, nov. sp. PI. XXXV, fig. 1 a — d. 

Diagnosis. — Test small, circular, depressed ; upper and under surfaces flattened ; 
ambulacra straight, narrow, two rows of marginal homogeneous granules ; inter- 
ambulacra wide, four or five tubercles in each row ; decreasing gradually in size from above 
downwards ; apical disc large, border slightly undulated, surface flat, smooth ; ovarial plates 
without sutural lines or punctuations in the middle of the disc, and with ten round aper- 
tures near the outer border ; mouth-opening large, peristome deeply incised, lobes unequal. 

Dimensions. — Altitude, two lines ; latitude, four lines. 

Description. — This small Urchin exhibits a form of apical disc very unusual among the 



FROM THE UPPER GREENS AND. 173 

Salenid^. The test is depressed on the upper and under surfaces, and the sides are 
inflated between. The poriferous zones are narrow, and the pores unigeminal throughout. 
The aiubulacral areas are straight and narrow, with twelve pairs of marginal, close-set, 
homogeneous granules, and a few granulations between them at the widest part thereof 
(fig. 1 d). The inter-anibulacral areas are wide, and filled with two rows of large tubercles, 
four in each row ; those in the upper part of the area are the largest, and they gradually 
diminish in size from above downwards ; the bosses of the tubercles are very prominent, and 
their summits sharply crenulated ; the mammillon likewise is large ^g. 1 d). Two rows of 
large granules occupy the miliary zone, and describe a zig-zag ornamentation on each side 
of the mesial suture, and two granules occupy the angles of each of the plates at their zonal 
side, so that the test of this small species has a highly ornamented appearance (fig. 1 c, d). 

The apical disc is large, solid, and remarkable for the absence from its ovarial plates of 
sutural lines or punctuations ; its border is thickened, and recurved, and near this marginal 
bourrelet are ten wide equidistant punctures (fig. 1 a) ; the vent is round, the periprocte 
annulated, not much elevated, and slightly excentral (fig. 1 a,c). 

The mouth-opening is very large, one half the diameter of the test ; the peristome is 
deeply incised, and the oral lobes are slightly unequal (fig. 1 b). 

Jffinities and Bifferences. — Salcnia Loriolii resembles Salenia minima in the closely 
united sutures of its apical disc, but differs from it in the larger development of its tubercles 
and wideness of its mouth-opening. It differs from Salenia Besori, associated with it in 
the same " terrain" in which it is found, in possessing larger tubercles, a smooth disc without 
punctuations, and a much larger mouth-opening. A comparison of the capital figures of 
these two Salenice on the same plate places their affinities and differences better before the 
student than any verbal description. 

Locality and Stratigrapldcal Position. — This rare specimen belongs to the British 
Museum, and was collected from the Upper Greensand near Warminster. 

I have dedicated this Urchin to my friend Monsieur P. de Loriol, of Geneva, one of 
the learned authors of the ' Echinologie Helvctique,' and of several other important works 
on the Geology and Palaeontology of Switzerland. 



Salenia Desori, Wright, nov. sp. PI. XXXV fig. 2 a—f. 

Biagnosis. — Test small, circular, depressed, upper surface convex ; ambulacra straight, 
narrow, with two rows of mammillated granules ; inter-ambulacra wide, four or five 
moderate-sized tubercles in each row ; pores unigeminal throughout ; apical disc promi- 
nent, with large punctuations along the sutural lines ; mouth-opening moderate ; peristome 
deeply incised ; lobes nearly equal. 

Bimensions. — Latitude, four and a half lines ; altitude, two and a half lines. 

Bescription. — This pretty little Salenia was collected with S. Loriolii in the Upper 



174 SALENIA 

Greensaiid of "Wiltshire. The test is small and circular ; the upper surface convex, and 
the base flat; the sides are inflated, and the disc conspicuous and prominent. 

The ambulacral areas are straight, with two rows of prominent homogeneous granules 
on their margins, and oblique rows of small granulations, thi'ee in each, between every 
pair of marginal granules (fig. 2/, 2 c). The pores are unigeminal, the pairs slightly 
oblique, and the zones narrow and straight. 

The inter-ambulacral areas are wide, and the two rows of primary tubercles are placed 
close to the pores, so that the miliary zone is wide and filled with granules of different 
sizes (fig. 2 c) ; the tubercles are of moderate dimensions, and gradually decrease from 
above downwards. Four of the five sides of each plate are encircled with a row of 
mammillated granules (fig. 2/). 

The apical disc is large, solid, and prominent, the border gently undulated, and the 
sutural lines soldered up ; in lieu thereof, there are three large punctuations between tlie 
junctions of the three anterior ovarial and sur-anal plates, and between all the ocular 
plates and ovarials ; the oviductal holes are large ; the vent is round ; the periprocte 
thickened, ])rominent, and slightly excentral (fig. 2 a, 2 d). 

The mouth-opening is nearly half the diameter of the test ; the peristome is deeply 
incised, and the lobes are nearly equal (fig. 2 b). 

Affinities and Differences. — Salenia Besori resembles S. gibba. It has, however, fewer 
granules in the ambidacra, the inter-ambulacra are more regularly developed, the apical 
disc is without sutures, and the mouth-opening is larger in proportion to the diameter 
of the test. 

Locality and Stratiyraphieal Position. — This rare Urchin was collected from the Upper 
Greensand near Warminster. I have dedicated it to my friend Professor E. Desor, of 
Neuchatel, one of the learned authors of the ' Catalogue raisonne des fichinides ' and 
' Echinologie Helvetique,' and author of the ' Synopsis des Echinides fossiles ' and many 
other valuable works on natural science. 



SalEiNIA gibba, Agassis. PI. XXXIV, fig. 4 a, b, c, d, e. 

Salenia gibba, Jgassiz. Monogr. des Snleniea, p. 13, pi. ii, figs. 9 — Ifi, 1838. 

— — Ayassiz ei Desor. Catalog, rais. des Echinides, Ann. Sc. Nat., 3e serie, 

t. vi, p. 341, 1846. 

— — Bronn. Index Palaiontologicus, p. 1107, 184". 

— — d'Orhigny. Prod, de Pal. strat., t. ii, p. 180, 1850. 

— — Morris. Catalogue of British Fossils, 2nd ed., p. 89, 1856. 

— — Piclet. Traite de Paleontologie, t. iv, p. 248, 1857. 

— — Cotteau. Paleontologie Frau9aise, Terrain cretace, torn, vii, p. 151, 

pi. 1035, figs. 13—20, 1865. 

Z>^ffy??oiM-.— Test small, circular, Upper surface inflated, gibbous, under surface flat, 



FROM THE UPPER GREEN SAND. 175 

sides rounded ; ambulacra narrow, flexed, two rows of marginal, closely set, mammillated 
granules, with intermediate graiudation ; poriferous zones Hexed ; pores small, oblique, 
unigeminal; inter-ambulacra wide, tubercles large and prominent above, four or five in a 
row. Apical disc thick, gibbous, subconical ; sutural impressions deep, punctuations large, 
vent circular, periprocte elevated. 

Dimensions. — Specimen a. Altitude, two lines ; latitude, four lines. 
„ b. Altitude, five lines ; latitude, six lines. 

Description. — The type specimens of this species figured by Professor Agassiz and 
M. Cotteaii, from the Cenomanian of France, have a more elevated gibbous test 
than any of the specimens referred to Salcnia (jihha that I have seen from the Upper 
Greensand of England. The shell is small and circular, the upper surface elevated, 
the under surface flat, and the sides inflated. The ambulacral areas are narrow, and 
flexed in their upper third ; they have two rows of mammillated marginal granules set close 
together, from eighteen to twenty in a series (fig. 4 e), and the surface of the space 
between the granules is covered with a microscopic granulation. The poriferous zones 
are depressed, and follow the flexures of the areas ; the pores are small, round, and 
unigeminal, and disposed in oblique pairs, the two pores forming a pair being separated 
by a septal granule (fig. 4 e). 

The inter-ambvdacral areas are wide, and the tubercles, of which there are four or 
five in a series, are large, prominent, and distant at the upper surface, and small, 
granuliform, and closely set together below (fig. 4 b and e)\ the miliary zone is narrow and 
sinuous, and provided with unequal granules ; some of these are large and mammillated, 
and disposed around the primary tubercles in incomplete circles; others are smaller, and 
fill the lower portion of the zone with a sparse granulation. 

The apical disc is thick, irregularly round and prominent (fig. 4 c, d), and the plates are 
unequal. The sutures are open and incised, and the punctures deep ; in some specimens 
figured by M. Cotteau the disc is thick, gibbous, and subconical, and the impressions are 
wide and deep ; the surface of the ovarial plates has small attenuated elevations, which 
converge at the centre of the plates. The ocular plates are sub-triangular, and a[)pear to 
be perforated in the middle ; the sur-anal plate is large and thick, and the oviductal lobes 
pierce the centre of the plates (fig. \d). The vent is sub-circular, and the periprocte 
prominent, with an aniudar projecting border. 

The mouth-opening is small, rather more than one third the diameter of the test 
(fig. 4 h). The peristome is slightly incised, and the oral lobes are nearly equal. 

JJpnities and Differences. — In his ' Synopsis des Echinides fossiles,' my friend 
Professor Desor considers S.(/ibba as simply a variety of 8. scuti(jera ; it appears, however, 
to have a more infiated gibbous form, with more flexuous ambulacra, a thicker apical 
disc, more unequal in outline, and marked with larger and deeper perforations ; and the 
mouth-opening is hkewise proportionally smaller. 

The structure of the apical disc allies 8. gibba to 8. Bourgeoisi ; the test of the 



176 SALENIA 

latter is much less inflated, the apical disc thinner and more depressed, the ambulacra 
are straighter, and the mouth-opening wider. 

Locality and Stratiyraphical Position. — The specimen I have figured belongs to the 
British Museum, and was collected from the Upper Greensand near Longleat, Wilts, where 
it is extremely rare. This species appears to be equally scarce in France ; as it was 
obtained from the Cenomanian = Upper Greensand, in the " He d'Aix" (Charente-Infe- 
rieure). From this locality the type specimens in the Musee de Paris and others in 
private collections were collected. 



B. — Species from the Grey Chalk. 

Salenia Austeni, Torhes. PI. XXXVII, figs. 1, 2. 

Salenia Austeni, Forbes, MS. Woodward, Mem. Geol. Siirv., Decade V, App., 1856. 
— — Forbes. In Morris's Catalogue of British Fossils, p. 89, 185-1. 

Diagnosis. — Test tumid, more or less elevated; ambulacra prominent, slightly 
flexed, two complete rows of remote marginal granules and two incomplete rows of smaller 
granules within ; inter-ambulacra with two rows of tubercles, five in each, decreasing in 
size from above the ambitus to the peristome. Miliary zone wide, sparsely covered with 
granules. Apical disc small, thick, prominent ; sutures marked by regular punctuations ; 
vent elevated, periprocte projecting, having a sharply crenulated border. 

Dimensions. — Altitude, five tenths of an inch ; latitude, seven tenths of an inch. 

Description.— 1\\\s, beautiful Salenia has in general a tumid body, with a narrow base, 
inflated at the sides, and convex on the upper surface, the vent being very excentric, elevated, 
and prominent; in some examples, however, the upper surface is more or less depressed, 
and approaches the form of S. petalifera. 

The ambulacral areas are narrow, nearly straight, and very prominent ; they have two 
complete rows of remote marginal granules, twenty-four in each (fig. 1 c/), and two 
incomplete rows of smaller central granules, which occupy two thirds of the area (fig. 1/). 
The poriferous zones are narrow and slightly flexed ; the pores are very small, oblique, 
and unigeminal, ten pairs occupying the height of a single plate (fig. 1/and ^7). 

The inter-ambulacral areas are wide, and regularly developed (fig. 1 a), with two rows of 
primary tubercles, gradually diminishing in size from the upper to the lower part of the 
area, those near the disc being large, and those near the peristome small. Fig. 1 e shows 
an entire area magnified four diameters; the tubercles are seated near the poriferous 
zones ; each is surrounded by a wide, areolar space, and around the margin thereof three 
parts of a circle of six to eight large round granules are placed (fig. 1 d, e, g). 

The miliary zone is wide throughout, and sparsely covered with small granules, especially 
near the discal region (fig. 1 d, e). The base is concave (fig. 1 b), and highly ornamented 



FROM THE GREY CHALK. 177 

by the numerous small close-set tubercles of the inter-ambulacra, the large granules of 
the ambulacra, and the width of the miliary zones. The mouth-opening is large, more than 
one third the diameter of the test ; the peristome is deeply incised, and forms ten nearly 
equal-sized lobes (fig. 1 b). 

The apical disc is small and thick, and rises above the test (fig. 1 c and d). The 
two antero-lateral and the left postero-lateral plates have a rhomboidal figure, and 
are nearly the same size. The right postero-lateral, the single plate, and the suranal are 
small in consequence of the encroachment of the vent ; the posterior border of the 
suranal is thickened and elevated (fig. 1 c, d, i), and rises to form the anterior wall 
of the periprocte ; the sutures between the three anterior ovarial plates are each 
marked by six deep punctuations, which define their line of junction ; and the sutures, 
uniting the ocular with the ovarial plates, have each three deep punctuations (fig. 1 c and 
fig. 1 i). The test I have figured has not the perforations in the ovarial sutures as distinctly 
marked as the test which now lies before me for description, so that this character varies 
in different specimens. The vent is round and elevated, and placed near the posterior 
part of the disc (fig. 1 c). The periprocte projects upward and backward (fig. 1 a and (/), 
and forms a crenulated rim around the aperture (fig. 1 a, fig. 1 d, and fig. 1 i). 

Affinities and Differences. — In a large majority of specimens the general form of the 
body in 8. Austeni differs from S. j)etaUfera in being more globose and elevated. The 
apical disc is smaller in diameter, and thicker in substance. The vent is likewise more 
elevated, the periprocte more produced, and its margin sharply crenulated. In the 
structure of the areas, such as the character of the granules in the ambulacra, and the 
tubercles in the inter-ambulacra, there is a close resemblance between these portions of 
the test in both species. 

Locality and Stratigraphical Position. — S. Austeni is the most abundant species in 
the Lower or Grey Chalk, near Folkestone ; from this locahty and stratum it has been 
collected by my kind friend, the Rev. T. Wiltshire, F.G.S., to whom I am indebted for 
several fine specimens given to help me in my work. 

History. — Named by the late Professor Edward Forbes, but not described by him. 
A brief diagnosis of the species was given by my late friend Dr. Woodward, in the 
Appendix to the Fifth Decade of the ' Memoirs of the Geological Survey.' It is now figured 
and described in detail for the first time. 



Salenia Clarkii, Forbes. PL XXXVIII, fig. 1 ; PI. XXXIX, fig. 1 ; PI. XLII, 

figs. 1, 2, 5. 

Salenia Clarkii, Forbes. In Morris's Catalogue of British Fossils, p. 89, 1856. 
— — Woodward. Mem. Geol. Surv., Decade V, App., p. 5, 1856. 

Diagnosis. — Test globose, elevated, flattened on the upper and under surfaces; 

23 



178 SALENIA 

ambulacra narrow, two complete rows of marginal granules, and a few small central ; inter- 
ambulacra wide, two rows of primary tubercles large in the upper part, small below ; 
apical disc half the diameter of the test, plates roughened with raised points ; each ovarial 
plate with five fun-ows leading to the large sutural pores. Spines slender, cylindrical, 
finely striated and granulated, the longest exceeding If inches in length, and less than one 
line in diameter ; frequently forked at their extremities, and sometimes bent and otherwise 
distorted. 

Dimensions. — Height, nine twentieths of an inch ; latitude, thirteen twentieths of an 
inch. 

Description, — This very distinct form of Salenia has an elevated body, depressed and 
flattened on the upper and under surfaces ; the ambulacral areas are narrow and straight 
(fig. 1 d,) with two complete rows of marginal granules, about twenty in each ; within these 
are two incomplete rows of small irregular granules, having a microscopic granulation 
scattered around their base. Fig. 1 ^ shows an ambulacral area magnified four times, 
and exhibits the increase in volume of the marginal granules near the base of the area. The 
poriferous zones are narrow ; the pores form oblique pairs with a thick septum between, and 
having a small granular elevation on the sm'face : fig. 1 h shows this structure magnified 
six diameters, as well as the minute granulation on the surface of the plates, and the 
comparative sizes of the marginal and central granules in the area. The number of pores 
opposite each large plate is eiglit or nine pairs. 

The inter-ambulacral areas are wide above and narrow below ; there are six primary 
tubercles in each of the two rows, and of these the four above the ambitus are much the 
largest ; those on the under side are much smaller and set closely together ; all the tubercles 
have wide areolar spaces, which are encircled for three parts of their circumference with a 
series of large, remote, well-developed granules. Fig. 1/ shows an entire inter-ambulacral 
space magnified four diameters, and fig. 1 /^ a single plate with its primary tubercle, 
areolar space, and circle of marginal granules, with the poriferous zones and ambulacra, 
magnified six diameters. The miliary zone (fig. 1/) is wider below the ambitus, and is 
here filled with an abundant granulation (fig. 1 c, fig. 1/) ; above the ambitus, the large 
size of the tubercles diminishes the width of the zone, and the tubercles here are fewer 
and larger (fig. 1/, fig. 1 b, and fig. 1 d). 

The apical disc is one half the diameter of the test, and the surface of the plates is 
roughened with many raised points (fig. 1 b) ; each ovarial plate has five furrows leading 
to the sutural pores, which have an arrangement similar to the punctuations on the disc 
in S.petalifera ; a semicircle of seven punctures indicates the sutures by which the sur-anal 
is united to the three anterior ovarials ; one large and two smaller punctures mark the 
line of union between the ocular and ovarial plates. In fig. 1 e the apical disc is magnified 
four diameters ; and the sutural punctuations are very correctly delineated in this drawing. 

The spines of Salenia ClarJcii are very well preserved with the test in the unique 
specimen belonging to the Museum of the Royal School of Mines, and which I have figured 



FROM THE LOWER WHITE CHALK. 179 

in PI. XXVHI, fig. 2 a. The spines are slender, cylindrical, finely striated, and granulated ; 
the longest exceed If inches in length, and are less than the twelfth of an inch in diameter j 
some of the spines are bent, as in figures 3 and 4, some are spatulate (fig. 2 h), and others 
are forked (fig. 2 c) at their extremities. The base of the spine around the milled ring 
has fine longitudinal lines extending a short distance up the stem, which is likewise covered 
by finer microscopic lines (fig. 2 d, and figs. 3 and 4) extending along the stem. 

Affinities and Differences. — This species very much resembles 8. gihba ; but, according 
to Dr. Woodward, it is entirely distinct from the mould of Professor Agassiz's original 
example of that species. 

Locality and Stratigraphical Position. — Salenia Clarkii is very rare in the Grey Chalk 
near Folkestone ; from this " terrain " the specimens in the Royal School of Mines and the 
British Museum were obtained. 

Histonj. — First named by the late Professor Edward Forbes, in his additions to the 
Echinodermata in the 2nd edition of Professor Morris's Catalogue of British Fossils. 
A diagnosis of the species was subsequently drawn up by Dr. Woodward, in his Appendix 
to Decade V, Memoirs of the Geological Survey, illustrative of Organic Remains. It is 
now figured in detail from specimens contained in the Cabinet of the Rev. T. Wiltshire, 
F.G.S., and in both our National Collections, 



B. — Species from the Loioer White Chalk. 
Salenia granulosa, Forbes. PI, XLI, figs. 2, 3 ; PL XLIII, fig. 1 a — h. 

Salenia scutigera, Forbes. In Dixon's Geol. Foss. Susse.x, pi. ?,AQ, pi. xxv, fig. 24, 
1850. 

— HELIOPHOKA, Sorignet. Oursins de I'Eure, p. 20, 1 S.'iO. 

— GRANULOSA, Forbes. In Morris's Catalogue of Brit. Foss., p. 89, 1854. 

— - Woodward. Mem. of Geol. Siirv., Dec. V, 1856. 

— INCRUSTATA, Cotteau, in Desor's Synops. des Ech. foss., p. 152, 1856. 

— GRANULOSA, Pictet. Trait^ de Paleontologie, t. iv, p. 218, 1857. 

— — Cotteau. Paleontologie Francaise, Terrain Cretace, torn, vii, 

p. 167, pi. 1039, figs. 6—21, 1860. 

Diagnosis. — Test small, circular, depressed, upper surface convex, under surface flat; 
ambulacra narrow, slightly flexed, with two rows of marginal mammillated granules ; inter- 
ambulacra wide, much covered by a prolongation of the ovarial plates, tubercles small, 
surrounded by areolas ; apical disc very large, covering like an incrustation nearly the 
entire upper surface; the flat ovarial plates have flexuous lines of granular processes 
diverging from their centres, and the convex oculars have similar hues extending over them 
from their inner side ; the sutures smooth, and without impressions. 



ISO SALENIA 

Bimensions. — Specimen a. Altitude, four lines ; latitude, five lines. 

„ b. Altitude, four and a half lines ; latitude, six and a half lines. 

Description. — This beautiful species was first noticed by M. I'Abbe Sorignet, in his 
description of ' I'Oursins de I'Eure,' and referred by him to Ili/posalenia heliophora from 
the Upper Chalk (Danian) of Ciply, which M. Desor' described as " distinguished by its 
very much ornamented disc, each ovarial and ocular plate being the centre of a system of 
fine ridges, that radiate in all directions." This species was not figured by Sorignet; and 
I have not yet seen a French specimen to compare with our Urchin from the lower 
white gritty Chalk of Dover, where it has hitherto only been found. 

The test is small and circular, the upper surface convex, the lower flat, and the sides 
rounded and moderately inflated (PL XLI, fig. 2c; PI. XLIII, fig. 1 d). The ambulacral 
areas are narrow, straight, or slightly flexed, with two niai-ginal rows of round prominent 
granules, twelve to thirteen in each ; those near the base are large and raammillated 
(PI. XLI, fig. 1 e) ; those at the ambitus smaller, and on the upper part very small and 
closely placed together ; the intermediate space being filled with an unequal microscopic 
granulation, which extends horizontally between the marginal granules. 

The poriferous zones are narrow, the pores unigeminal, and set in oblique pairs, 
separated from each other by a small granuliform elevation of the septum ; there are 
about eight pairs of holes opposite one of the large inter-ambulacral plates (PI. XLI, 
fig. 2/; PI. XLIII, fig. 1 li, in which I have given accurate figures of this part of the 
test, magnified six times). 

The inter-ambulacral areas are wide (PI. XLI, fig. 2 d), and covered over in their 
upper third by a lateral extension of the ovarial plates ; there are three or four tubercles in 
each row, which rise a little above the ambitus; only one or two of these tubercles in 
each series are well developed, surrounded by a circular areola, and having a large boss 
and prominent mammillon (PI. XLIII, fig. 1 // ; PI. XLI, fig. 2/). The miliary zone is 
narrow, and its granules unequal in size and structure ; the larger are distinctly mammil- 
lated, and disposed in a regular crescentic form around the areolae ; where the latter abut 
against the poriferous zones the granules are absent (fig. 1 h, fig. 1 g) ; the other granules 
are small and irregularly disposed, filling up the space with a fine granulation (fig. 1 h). 

The mouth-opening is very small (PI. XLI, fig. 2 (5 ; PI. XLIII, fig. 1 c), in excess of 
one third the diameter of the test ; the peristome is divided into ten equal lobes by well- 
marked incisions. 

The apical disc is very large and pentagonal, occupying a great part of the upper 
surface (PI. XLIII, fig. 1 b, d, e). It is convex above, and so thin and closely adherent to 
the shell at the borders that it appears to blend witli the plates of the test ; the ovarial 
plates are large, and of an irregular form ; their surface is sculptured with small unequal 
punctuated lines, which appear to radiate outwards from the oviductal holes situate near 

' 'Synopsis des ficliinides fossiles,' p. 148. 



FROM THE LOWER WHITE CHALK. 181 

the centre of the plate ; the ridges on the plates resemble numbers of prominent gra- 
nulations projecting outwards, which impart a granulose aspect to the surface of the disc, 
and is very well represented in PI. XLI, fig. 3, and PI. XLIII, fig. 1 e ; a process 
of each plate extends into the inter-ambulacra, the ornamentation of which differs from 
that in the middle of the plate ; the punctuated lines are widest and more flexed, and this 
incrusting process appears to blend with the granidations on the test ; the sur-anal plate is 
elevated, and forms the anterior border of the periprocte ; the ocular plates are heart- 
shaped, and more prominent than the ovarials ; they are likewise covered with punctuated 
flexuous ridges, but the lines are more tortuous, and the style of ornamentation is different 
(PI. XLIII, fig. 1 e) from that on the ovarials. 

The spines are not preserved in any of the Dover specimens that have passed through 
my hands. M. Cotteau, however, describes them as elongate or aciculate, cylindrical, or a 
little compressed, provided with fine longitudinal sub-granular striae ; their greatest dia- 
meter is near the neck of the spine, and they regularly diminish to the upper extremity, 
which is pointed. The collarette is short or absent, the milled ring very prominent and 
strongly striated, and the rim of the articular cavity crenulated. 

Affinities mid Differences. — Salenia granulosa, Forb., strongly resembles Hyposalenia 
heliophora, Desor, from the Chalk of Maestricht ; it is distinguished from it, however, 
according to M. Cotteau, by being smaller in size, and having its upper surface more 
conical, its ambulacra furnished below the ambitus with smaller granules, and in possessing 
fewer primary tubercles in the inter-ambulacra ; the apical disc is thinner and distinctly 
circumscribed, the flexuous ridges on the ovarial and ocular plates are more irregular and 
more granular, and the periprocte is situated to the right of the axis. 

Locality and Stratic/rapldcal Position. — This fine species is found in the hard gritty 
whitish beds of the Lower Chalk at Dover, where it is associated with Cyphosoma simplex, 
Forb., and numerous Polyzoa. All the specimens I have examined were obtained from 
this one locality, where it is rather rare. 

M. Cotteau states that it is a common species in the Jltage Senonien of Vernonnct, 
Giverny, Petit-Andely, Penterville (Eure), and the environs of Beauvais (Oise). 

History. — M. I'Abbe Sorignet first described in 1850 this Salenia in his interesting 
memoir 'I'Oursins de I'Eure,' and identified it as the Hyposalenia lieliophora, Desor. In 
the same year the late Professor Forbes, in Dixon's ' Geology of Sussex,' gave a figure of 
this Urchin, which he referred to Salenia scutiyera, Gray ; subsequently, in the second 
edition of Morris's ' Catalogue of British Fossils,' 1854, Forbes separated it from that species 
under the MS. name S. granulosa. In 1856 M. Cotteau, in M. Desor's 'Synopsis des 
fichinides fossiles,' named the specimens collected and identified as Hyposalenia helio- 
phora by M. Sorignet, Salenia incrustata, Cott. ; he gave the following diagnosis of 
this form : — " Small Urchins, well characterized by their very large apical disc, thin, and 
little in relief, and incrusting in some manner the whole of the upper surface of the test. 
The ovarial plates present a series of small points disposed like rays around many centres ; 



183 SALENIA 

the disc is so intimately soldered to the test that it is sometimes difficult at first sight to 
recoo-nize its limits." A comparison of the English with the French specimens showed 
them to be specifically identical, and thus M. Sorignet was the discoverer, but Forbes the 
namer, of this well defined species. 



c. — Species from the Upper White Chalk. 

Salenia geometrica, Agassiz, 1838. PI. XLIII, fig. 2 a — y, fig. 3 a, h. 

Salenia geometrica, Agassiz. Mongr. Ecbinodermes, pi. i,figs. 25 — 32, p. 11, 1838. 
CiDARis ? VESicuLOsus, Por^/ocA-. Report on the Geology of Londonderry, pi. xviii, 

fig. 5, p. 358, 1843. 
Salekia scctigera ? Forbes. In Di.xon's Geology of Sussex, pi. xxv, fig. 23, 1850. 

— PoRixocKii, Forbes. In Morris's Cat. of Brit. Foss., 2nd ed., p. 89, 1854. 

— — Woodioard. Mem. of the Geol. Surv., Decade V, Append., 

p. 5, 1856. 

— GEOMETRICA, Cotteau et Triger. Echiuides du Depart, de la Sarthe, pi. xlvi, 

figs. 1—7, 1860. 

— SCUTIGEKA, Cotteau, pars. Pale'ontologie Fran9aise, Terrain Cretace, torn. 

vii, p. 154, pi. 1036, 1864. 

Diagnosis. — Test sub-globose, elevated, convex above, contracted and concave beneath ; 
ambulacra narrow, slightly flexuous, marginal granules separated by two rows of granulets ; 
inter-ambulacra wide, plates slightly radiate ; two rows of tubercles, seven to eight in each, 
the ambital large, the basal small ; miliary zone with large sparse granules and minute 
granidations ; apical disc moderate, of a regular geometrical figure, flattened, two thirds 
the diameter of test; sutures punctuated; plates nearly equal in size; mouth-opening 
small, one third the diameter of test. 

Dimensions. — a. Altitude, eight lines ; latitude, nine lines (Mr. Searles Wood's 
specimen). 
b. Altitude, eleven lines ; latitude, one inch (Mr. King's specimen). 

Description. — The species to which this Urchin has been referred is considered by 
Professor Desor and M. Cotteau to be the Salenia scutigera. Gray ; as I am doubtful 
about the identity of Dr. Gray's form, I have retained the name given by Professor 
Agassiz, seeing that he has published good figures and a clear description of this species 
in his beautiful Monograph on the Salenies. S. geometrica is the largest species of the 
genus at present known. The test is elevated and sub-globose, slightly flattened at the 
upper and under surfaces. The ambulacral areas are narrow and slightly flexed, with two 
marginal rows of close-set granules, fourteen to sixteen in each, and separated by a 
double row of minute granulation extending down the middle of the area (PI. XLIII, 
%• 2 c,g,f). The poriferous zones are narrow and slightly flexed, the pores unigeminal 



FROM THE UPPER WHITE CHALK. 183 

and oblique (fig. r2/), and the septa between the pores support prominent granuliform 
elevations (fig. 2y). 

The inter-ambulacral areas are very wide throughout (fig. 3 c, e, and fig. 3 a, b) ; they 
are formed of two series of deep plates, seven in each, that support large prominent 
tubercles (fig. \Le,g, fig. 2>a). The four ambital tubercles are the largest; they have 
well-defined areolas, prominent bosses, and moderate-sized mammelons. A series of mam- 
millated granules surround the areola, except where it abuts against the zones (fig. 2 
e andy). The miliary zone is wide, and filled with numerous small granulations (fig. 3 e) 
in addition to the larger granules that encircle the tubercles. 

The apical disc, two thu'ds the diameter of the test, has a regular geometrical figure, 
hence the origin of the specific name (fig. 2 a, 6) ; it is circular, slightly convex, and a 
little elevated at the vent. The ovarial plates have an irregular hexagonal shape, their 
outer sides are elongated and contracted, and the rounded external border lies within the 
circle described by the ocular plates, which have an irregular triangular figure, the largest 
side being turned outwards and slightly undulated (fig. 2 d) ; the sutures are fine, 
distinct, and regularly interrupted by small punctuated angular impressions; the oviductal 
holes open in the middle of the plates, and the orbits lie under the central projecting 
process (fig. 3 d) ; the surface of all the plates is quite smooth. The vent is slightly 
elevated, and the periprocte surrounded by a thick annulus (fig. 2 d, d) ; this aperture, 
nearly circular, occupies the posterior half of the sur-anal and the anterior halves of the two 
posterior ovarial plates. 

The mouth-opening is one third the diameter of the test (fig. 3 d) ; and the peristome 
is divided into ten unequal lobes. 

Affinities and Differences. — Salenia geometrica resembles ^S*. scutigera ; by some authors 
it is considered to be a large variety of the latter. M. Cotteau, in his beautiful Monograph 
on the ' Echiuides du Departement de la Sarthe,' figured and described this Urchin under 
the name Salenia geometrica, Ag., but in his later and most valuable contribution to the 
' Paleontologie ErauQaise' has united it yf'iih. Salenia scutigera ; he says, however,^ as to 
the Salenia geometrica, " la question est plus delicate et plus difficile a resoudre. Au 
premier abord, cette espece se distingue certainement du Salenia scutigera par plusieurs 
caracteres importants : sa taille est beaucoup plus considerable,, car sa hauteur depasse 
souvent 13 millimetres, et son diametre 17 miUimetres ; sa face superieure est plus 
elevee et plus sensiblement deprimee au sommet ; ses tubercules inter-ambulacraires sont 
plus nombreux, et la zone railiare qui les separe plus large, plus droite et plus granu- 
leuse; ses ambulacres sont plus longs et plus flexueux, et I'appareil apicial, relativement 
moins grand et moins epais, afFecte une forme plus pentagonale. Ces difierences se 
reproduisent chez un certain nombre d'individus avec une Constance qui n'est pas 
sans leur donner de la valeur ; aussi, dans nos ' Echiuides de la Sarthe,' n'avons-nous 
pas hesite a, maintenir la S. geometrica comme une espece parfaitement distincte. 

^ 'Paleontologie Fran^aise, Ter. Cretace,' tora. vii, p. 157. 



184 SALENIA 

"Les nombrenx raateriaux que nous avons sous les yeux, et que nous venons de com- 
parer, nous engagent aujourd'hui ii revenir sur cette opinion. Associes aux types les 
mieux caracterises il se rencontre des exemplaires cliez lesquels les differences que nous 
venons d'enuuierer s'effacent plus ou uioins, et qui tendent a se rapprocher, par des 
passages insensibles, du veritable S. scutigera. Les uns, tout en conservant leur grande 
taille, sont moins renfles, garnis de tubercules moins abondants, et presentent un appareil 
apicial plus developpe, plus epuis et arrondi au pourtour ; les autres, plus petits, ont un 
appareil apicial qui cesse peu a peu d'etre pentagonal, et tend, en s'agrandissant a s'ar- 
rondir sur les bords. lis appartiennent encore a la variete yeoMe^nca ; cependant ils 
ofFrent une grande ressemblance avec les exemplaires Cenomaniens ; quelquefois meme il 
est diiEcile de les en separer. 

" Woodward, d'apres Forbes, decrit sous le nom de S. Portlockii une espece d'assez 
grande taille, elevee, sub-globuleuse, a ambulacres etroits et sinueux, a disque apicial 
mediocrenient developpe ; ses caracteres la rapprochent beaucoup du 8. scutigera, var. 
geometrica. Peut-^tre devrait-elle y etre reunie." 

Locality and Stratigrapliical Position. — This fine large species occurs in tbe Upper 
Chalk of the North of Ireland, where it was collected by the officers of the Geological 
Survey, and figured in Colonel Portlock's ' Report on the Geology of the County of 
Londonderry.' It is found very rarely in the upper beds of white Chalk at Norwich and 
in Sussex, and flint moulds are not uncommon in the Gravel of Norfolk. The specimens 
figured Iselong to the British Museum. Mr. Searles Wood possesses a good example, and 
Mr. John King, of Norwich, has a large one which measures eleven lines in height and 
as much in diameter. There is also a fine specimen in the Hunterian Collection, Museum 
of the College of Surgeons (Woodward). 



Salenia magnifica, Wright, nov. sp. PI. XLIV, fig. 1, a — /. 

Diagnosis. — Test spheroidal, much elevated ; ambulacra nearly straight, two marginal 
rows of large mammillated and two internal rows of smaller granules; poriferous zones 
narrow, pores very oblique and unigeminal ; inter-ambidacra wide, two rows of tubercles, 
seven in each, the ambital and dorsal very large, the basal very small ; miliary zone wide, 
and sparsely covered with granulations ; apical disc large, plates smooth, sutures punc- 
tuated, vent large, oblong ; periprocte hexagonal, elevated, and projecting ; mouth-opening 
small, oblong. 

Dimensions. — Altitude, nine lines ; latitude, ten and a half lines. 

Descrijition. — This magnificent Salenia from the White Chalk belongs to the British 
Museum, and to the illustration of its finely preserved details I have devoted PI. XLIV. 
The test is spheroidal and much elevated, its altitude exceeding its diameter by one and a half 
lines ; the ambulacral areas are narrow and slightly flexed, with two marginal rows of large 



THE 



PALJIONTOGRAPHICAL SOCIETY. 



INSTITUTED MDCCCXLVII. 



VOLUME FOE 1873. 



LONDON 

MDCCClX.Xir. 



MONOGRAPH 



BRITISH FOSSIL 



ECHINODERMATA 



FROM 



THE CRETACEOUS FORMATIONS. 




BY 



THOMAS WRIGHT, M.D., F.R.S. Edin., F.G.S., 

COBBESPOSDING MEMBEK OF THE KOYAl SOCIETY OF SCIEKCES OP LIEGE, THE SOCIETY OF 
NATTIBAi SCIENCES OP NEUPCHATEL; SENIOR SUEGEON TO THE CHELTENHAM 
HOSPITAL; AND MEDICAL OPPICER OF HEALTH FOB, THE UBBAN 
SANITARY DISTRICTS OF CHELTENHAM, CHARLTON- 
KINGS, AND LECKHAMPTON. 



VOLUME FIRST. 

PART SIXTH. 
ON THE ECHINOCONID^. 

Pages 185—224 ; Plates XLV— LII. 



LONDON: 

PRINTED FOR THE PAL^ONTOGRAPHICAL SOCIETY. 

1874. 



FEINTED BY 
J. E. ADLAED, BAETHOLOMEW CLOSE. 



FROM THE UPPER WHITE CHALK. 1S5 

■close-set mammillated granules, twenty-six iu each roAV, larger at the base than in the 
upper part of the area. Within these are two rows of much smaller granules, twenty- 
two in each, less regular in their arrangement than the marginal rows (fig. 1 (/). The 
poriferous zones are extremely narrow and the pores disposed in very oblique pairs 
(fig. Iff), eight lying within the height of one of the large inter-ambulacral plates (fig. 1 i) ; 
the septum between each pair terminates in a grauuliform elevation (fig. 1 i). 

The inter-ambulacral areas are vi^ell developed (fig. 1 a, d, /), with two rows of 
tubercles, seven in each ; those in the upper part of the area and at the ambitus are large, 
and at the base small ; fig. 1 / shows one area magnified four diameters ; the three pairs 
of large tubercles i^early occupy the entire surface of their respective plates (fig. 1 i) ; the 
boss has a wide base, surrounded by a well-defined areola, and this is encircled by a 
series of eight large mammillated granules ; fig. 1 i shows one of these large plates, 
and fig. 1 i- gives a profile of one tubercle with its surrounding granules, both figures are 
magnified six diameters ; from the ambitus to the peristome the tubercles gradually 
diminish in size, and the four small basal nearest the mouth have a row of mammillated 
granules separating them from the poriferous zones (fig. 1/ and fig. 1 //). The miliary 
zone is wide, nearly of equal diameter throughout; and in addition to the large granules which 
form a series of crescents around the areolae the interspace is covered with small granules 
sparsely strewed over the surface of the plates (fig. 1 d, y, /). The apical disc is 
large and prominent, consisting of a series of thick plates ; fig. 1 a shows its natural size 
and I'elations, and fig. 1 i the same magnified four diameters. Three of the ovarial plates 
have an irregular hexagonal and two a rhomboidal figure (fig. 1 h and e) ; in all the 
oviductal holes are in the centre of the plates ; the sur-anal plate is much thickened and 
raised to form the anterior wall of the periprocte (fig. 1 a, h, d, e) ; the ocular plates are 
triangular, having their base undulated and turned outwards : the outer border of both 
the ovarial and ocular plates are placed within the circle having its centre at the anterior 
wall of the vent; the sutures are well marked and punctated with small angular im- 
pressions ; the vent is large and oblong (fig. 1 b, e), and the periprocte surrounded by a 
thick prominent annulus, which forms a conspicuous character of the test of this fine 
Salenia ; the vent is excentral (fig. T a, d), and looks obliquely backwards and to the 
right side. The base is narrow, and highly ornamented; the small primary inter- 
ambulacral tubercles are closely set together, and the large mammillated ambulacral 
granules are very conspicuous, and form a prominent band between the tubercles (fig. 
1 c, h) ; the miliary zone is wide, and filled with small close-set granules (fig. \f, c). 
The mouth-opening is oblong (fig. 1 e, /) about one third the diameter of the test. 
The peristome is decagonal, dividing the opening into ten unequal lobes ; each of the 
ambulacral lobes, which are the largest, have a double crescentic outHne, fig. 1 h, I -. 
this is the only species of the genus Salenia which possesses an oblong mouth-opening, 
and this forms, therefore, one of the specific characters by which it is distinguished from 
its congeners. 

24 



ISG COTTALDIA. 

Affinities and Differences. — This magnificent Salenia in point of size resembles S. 
fieometrica, var. Portlockii, ft-om the White Chalk. The test, however, is more elevated, 
the apical disc thicker and more prominent, and the inter-ambulacral areas resemble each 
other in the number and development of the tubercles in each rovi' ; the oblong vent and 
oblong mouth-opening are, however, special to S. magnifica. 

Locality and StratigrapJiical Position. — This Urchin was collected from the Upper 
Chalk near Norwich, and belongs to the British Museum collection. 



Genus — Cottaldia, Desor, 1856. 

Echinus, pars, Z^CBn!>, 1820; Mimster, 1826; Forbes, 1849. Arbacia, Gray, 1835. 

Cottaldia, Desor, 1856. 

Test small, sub-globular, sides inflated, more or less depressed at the poles. 
Shell lobed, divided into fifteen sections ; the five most prominent form the ambulacral, 
and the ten others, grouped in pairs, the inter-ambulacral areas. Poriferous zones 
narrow, straight ; pores unigeminal. Tubercles small, mammillated, imperforated, 
uncrenulated, very numerous, homogeneous, and forming on each plate a close-set hori- 
zontal row. Granules microscopic, placed on all the inter-tubercular spaces. Apical 
disc solid, narrow, forming a prominent ring, composed of five perforated, rhomboidal, 
ovarial plates, and five cordate oculars ; all the elements of the disc are covered with close- 
set granules. Mouth -opening moderate, lodged in a concave depression of the base ; peri- 
stome sub-pentagonal, decagonal, and feebly notched. 

The genus Cottaldia forms a very natural group of small fossil Urchins appertaining 
to the Cretaceous and Tertiary formations ; well characterised by their sub-globular form, 
and the abundance and uniformity of their tubercles, arranged in horizontal series 
over the entire test. Much confusion formerly existed between Arbacia, Gray ; Echino- 
ciDARis, Desmoulins ; Poltcyphus, Agassiz ; and Magnosia, Michelin. This, however, 
has been in a great measure removed by clearer definitions of the genera retained, the 
suppression of those that were doubtful, and the establishment of the genus Cottaldia. 

The uniformity of the tubercles, Prof. Desor remarks, attains its maximum in this 
small genus; and this character accords with its peristome, which is narrow and depressed, 
and its pores, which are unigeminal throughout the zones. These characters distinguish 
Cottaldia from the neighbouring types with which it has been confounded up to the 
present time. It is dedicated by M. Desor in honour of his friend M. Cotteau, the 
learned author of the ' Echinides fossiles de 1' Yonne,' and of the ' Paleontologie Fran^aise.' 



FROM THE UPPER GREENSAND. 187 



CoTTALDiA Benetti^, Koiliff. PI. XLV, figs. 1, 2, 3. 



EcHTNCS BENETTI^, Konig. Icones Foss. Sectiles, p. 2, pi. iii, fig. 3,5, 1825. 

— GRANULOSUS, Munster, Pet. Germ., p. 125, pi. xlix, fig. 5, a. b, 1826. 

— — Grateloup. Mem. Oursins Fossiles, fichiiiides, p. 82, 1836. 
Aebacia granulosa, Agassiz. Cat. Syst., p. 12. 

— — Morris. Cat. of British Fossils, p. 48, 1843. 

— — Agassiz et Desor. Cat. Rais. des Echinides, Ann. des Sc. 

Nat, 3rd series, vol vi, p. 356. 
Echinus granulosus, Forbes. Mem. Geol. Surv. Organic Remains, Decade I, pi. 

vi, 1849. 

— — Forbes in Morris. British Fossils, 2nd ed., p. 79, 1854. 
Cottaldia granulosa, Desor. Synop. des Echinid. Foss., p. 114, pi. xix, fig. 1 — 3, 

1858. 

— — Cotteau. Paleontologie Fran9aise, Ter. Cretace, t. vii, p. 789, 

pi. 1193 and 1194, 1—9, 1866. 

Diapiosis. — Test small, globular, nearly equally depressed at both poles ; plates 
of both areas very narrow, the inter-ambulacral supporting a horizontal series of small, 
equal-sized, imperforate, spiniferous tubercles, from eight to twelve in a row ; the ambu- 
lacral tubercles of the same size, less numerous, and packed obliquely together ; poriferous 
zones very narrow, pores unigerainal throughout ; apical disc very small ; mouth-opening 
large, placed in a depression ; peristome slightly decagonal, notches feebly marked. 

Dimensions. — Altitude, nine twentieths of an inch ; latitude, six tenths of an inch ; 

the relation of the altitude to the latitude varies considerably, 

some being more conical, others more depressed than others ; in 

four specimens the ratio was 17 to 10, 15 to 11, 12 to 11, and 

12 to 8. 

Description. — This beautiful little Urchin was first figured by M. Konig in his 

' Icones Fossilium Sectiles ' under the name of Echinus Benettice, in honour of a lady 

who had long made the fossils of Wiltshire her especial study, and had published a valuable 

catalogue of the same ; a year later the German forms of this species were figured and 

described in Goldfuss' ' Petrefacta Germanise ' imder Count Minister's name Echinus 

granulosus ; subsequently it was entered in Agassiz and Desor's ' Catalogue Raisonne des 

Echinides ' at the head of the list of their second type of Arhacice with uniform 

tubercles on all the surface of the test; and, lastly, M. Desor established the genus 

Cottaldia for this small group, which was characterised by having the surface of the small 

test covered with spiniferous tubercles, uniform in size and regular in arrangement. 



]SS COTTALDIA. 

forming distinct liorizontal rows on the plates of the inter-ambnlacra, and having the 
pores unigeminal throughout the narrow areas. 

The test varies in form in different individuals from nearly a globular shape, as in PL 
XLV, fig. 1, to forms more or less depressed at both poles, as in figs. 2 and 3. The 
uniformity in size and arrangement of the numerous small tubercles covering the surface, 
and the division of the same into five broad and five narrow segments (fig. 1 d), by 
the poriferous zones radiating from the circumference of the apical disc (fig. 1 h) and 
converging below around the peristome (fig. 1 c), impart a remarkable physiognomy to- 
this pretty little Urchin ; the medial suture down the middle of the inter-ambulacra is 
often depressed, and then Cotfaldia Beneitia resembles a little melon, having its surface 
divided into fifteen lobes (fig. 1 b, d). 

The ambulacral areas are about one third the width of the inter-ambulacral, and at 
the ambitus there are three or four tubercles on each plate (fig. 2 h), with numerous small 
granules around them ; the outer rows of tubercles are the most persistent, and the inner 
rows in general are limited to the ambital region of the test ; the poriferous zones are very 
narrow, and the pores numerous and unigeminal throughout (fig. 2 h) ; near the base 
they show a disposition to fall into triple oblique pairs, as in the genus Echinus, but the 
deviation is so slight that it is only occasionally seen in exceptional specimens ; there 
are in general three pairs of holes opposite each ambulacral plate (fig. 1 e and fig. 2 b), 
so that in the specimen I am describing there are quite 100 pairs of holes in each zone. 

The inter-ambulacral areas are three times as wide as the ambulacral ; the plates are 
very narrow in proportion to their length, and in the specimen before me there are thirty- 
five plates in each column ; each plate has a horizontal series of small equal-sized spini- 
ferous tubercles ; in the longest plates at the ambitus there are from nine to eleven on 
each according to the age and size of the specimen under examination ; the tubercles of 
both areas are of the same size, but they are rather more closely set together, and more 
obliquely placed in consequence in the ambulacral areas (see fig. 1 e and fig. 2 b) ; the 
number of tubercles in each vertical row varies with the age and size of the specimen ; 
they are most numerous near the ambital region ; the rows nearest the poriferous zones 
are the longest and most persistent, and those near the miliary zone the shortest and most 
frequently absent. In some large specimens there is a depression in the line of the 
median suture in the inter-ambulacral areas, which gives this space a bilobed appear- 
ance; as these areas are nearly half the width of the ambulacral, the whole circum- 
ference of the test is divided by the five sutural depressions into ten poriferous zones 
and fifteen well-marked lobes, as represented in fig. 1 a, b, c, d, and this imparts a 
remarkable symmetrical neatness to the physiognomy of the Urchin. 

The mouth-opening is nearly circular, and about one half the diameter of the test (fig. 
1 c) ; the peristome, which is superficial, is very feebly notched opposite the zones. 

The apical disc is a small ring-like structiu'e slightly projecting from the surface of 
the test (fig. 1 b) ; the ovarial plates are sub-triangular (fig. 1 b), and perforated near 



ECHINOIDEA EXOCYCLICA. 189 

tlieir outer third b}' a large ovidnctal hole ; the madreporiform tubercle is feebly developed 
and occupies the inner portion of the right antero^lateral plate ; in most specimens the 
ocular plates are small and angularly reniforra, the orbit is excavated out of the centre of 
their outer margin, the elements of the disc are covered with numerous small granules, 
which are closely crowded together on the surface of all the plates. 

The test' is extremely thin, and the spines are at present unknown. 

Affinities and Differences. — There are very few species in the genus Cottaldia. C.conica, 
Agass., is merely an elevated form of C. gramdosa ; C. BucJdi, Steiniger, is a nearly 
allied species, from a Tertiary rock at Rommelsheim, near Friim. 

Loccdity and Stratigraphical Position. — This Urchin was formerly very abundant in 
the Upper Greensand of Warminster, and at Chute Farm, Wilts. On the Continent the first- 
described specimens were collected at Regensburg, Bavaria. In France, according to M. 
Cotteau, it is found at Villers-sur-mer (Calvados) ; le Havre, Rouen (Seine- Inferieure) ; 
Yimoutiers, La Perriere (Orne) ; La Madeleine (Eure) ; le Mans, Coulaine, Yvre-l'Eveque, 
les Bordiers, Nogent-le-Bernard, Gaville (Sarthe) ; Cherves-de-Cognac (Charente- 
Inferieure) ; La Bedoule (Var) ; very abundant in the Etage Cenomanien = Upper 
Greensand ; Environs of Royan (Charente-Inferieure) ; very, rare in the Etage Senonien 
:=. Low-er Chalk. . 



ECHINOIDEA EXOCYCLICA, Wright, 1855. 



Before entering upon the study of the Echinoidea exocyclica, it is due to the 
Echinological student to state in general terms the reasons that have led to the adoption 
of names for several generic groups so different from those in general use at the present 
time. In working out the materials for these Monographs it has been my most earnest 
endeavour to do justice to my predecessors and contemporaries in the same field of labour, 
by observing the most scrupulous care in reference to priority of date in each 
genus and species founded on figures or descriptions, or both; without a rigorous 
base of equity on this fundamental principle, it would be vain to hope for the stability of 
any sysjtem of nomenclature, or limits to the interminable list of synonyms which would 
result from its neglect. In every case, therefore, I have traced back the history of each 
genus and species to its original author, and have added his name and the date after 
each, so that justice is done to every naturalist who has enriched our science by original 
work. The following remarks were made in the preface to my Monograph on the Oolitic 



190 ECIIINOIDEA EXOCYCLICA. 

EcMnodermata, and twenty years' experience has only afforded additional evidence of 
their truth. 

" Many of the readers of this Monograph will probably be surprised to find some old 
generic names reproduced which have been long superseded by those of modern writers ; 
but a sense of justice to such authors as Van Phelsum, Breynius, Klein, and Leske has 
led me to consult their original works and restore the genera first described and figured 
by them, but omitted from the treatises of later authors on the same subject. 

" In the nomenclature of the Echuiodermata, had I merely gone back to the time of 
Linnaeus, as suggested by the Committee of the British Association in their Report made 
in 1842. I must necessarily have excluded the important work by Breynius,^ in which, 
for the first time, were proposed seven well-described and accurately figured genera of 
Uchinoidea, which, by some strange oversight, were not adopted by his contemporaries, 
although they have reappeared under new names in the works of later authors. On the 
principle of priority, therefore, I have restored the original genera so clearly defined by 
Breynius, even although it may occasion a temporary inconvenience in the names of some 
well-known forms of Urchins. 

" In every case where practicable the name of the author who either first recorded, 
described, or figured the species follows the specific name of the object without the 
addition of ' Sp.' adopted by some authors. By this mode justice is done to the original 
author and confusion avoided. The modern practice of inventing new generic terms and 
appending to the old specific name that of the individual who has merely clianged a 
word but discovered nothing cannot be sufficiently discountenanced, as it increases the 
confusion arising from an overloaded synonymy, and thereby retards the real progress of 
the natural-history sciences."'' 

The first author who described systematically and figured accurately many typical 
forms oiEchinidm was undoubtedly Breynius,' in his ' Schediasma de Echinis ;' he takes 
the general form of the test and relative position of the vent as the basis of his 
methodical arrangement, in which he groups the whole order into the seven following 
genera. 



I. Genus — Echinometra, Breynius, 1732. 

Shell more or less globular, the mouth and vent occupying the two poles. This 
genus was retained by Gaultieri, 1742 ; by Seba, 1758, and by Van Phelsum, 1770 ; but it 

' De Echinis et Echinitis, sive methodica Echinorum distribiitione, Schediasma. Gedani, 1/32. 
2 'Monograph on the British Fossil Echinodermata of the Oolitic Formation,' p. vii. Pal. Soc. vol. for 
18.55. 

8 Joannis Phillippi Breynii dissertatio physica de Polythalamiis— tanderaque Schediasma de Echinis 
niethodiee disponendis cum figuris. Gedaui, 1732. 



BREYNIUS' GENERA. 191 

was changed into Cidaris by Klein, in 1734, into Echiiiushy Linnseus, in 1758, and into 
Echinus and Cidaris by Lamarck in 1801, who suppressed the name Echinometra 
altogether. It has been restored to another group of Urchins by Agassiz in 1846, 
who unfortunately attributed the name to Klein instead of Breynius its author. 



II. Gemis — EcHiNOCONUs, Breynius, 1732. 

The mouth in the centre of the base, and the vent beneath, at the margin, or above 
the border ; the shell elevated, round, or conoidal. This generic name was ignored by 
Klein, 1734, who changed it to Conulus ; Leske, his commentator in 1778, changed it to 
EcMnites. Lamarck, 1801, omitted the names proposed by his predecessors, and gave 
that of Galerites to the same group; all the authors down to the time of Alcide 
d'Orbigny have followed Lamarck instead of Breynius, who nearly a century before 
had well described and figured this genus. 



III. Genus — Echinocorys, Breynius, 1732. 

* 

The test is helmet-shaped, with the mouth and vent beneath, the former aperture 
before, and the latter at the marginal border. This generic name was ignored by Klein and 
changed by him to Galea in 1734. It was retained by Leske, 1778, by Parkinson, 1811, 
and Mantell, 1832. Lamarck in 1801 proposed the new name Ananchytes for this group, 
which was retained and adopted by all subsequent modern authors down to 1853, when 
d'Orbigny restored to this form Breynius' original name Echinocorys. 



IV. Gettus — EcHiNANTHDs, Breyuius, 1732. 

Large, oblong, shield-shaped Urchins with petaloidal, ambulacral areas , the mouth- 
opening beneath near the centre, and the vent within or below the marginal border ; this 
genus was preserved by Gaultieri, 1742, and Leske, 1778. It was changed into Scutum 
by Klein, 1734; into Clypeaster by Lamarck, 1816; and into Echinolamjjas by Gray in 
1834. Agassiz and most other modern authors retained the name Echinolampas until 
d'Orbigny rightly restored the old original name Echinanthiis to all oblong Urchins with 
leaf-shaped ambulacra and the vent in the lower border. 



193 BREYiNIUS' MEMOIR 



V. Genus — Echinos-patagus, j8irey«2«s, 173i2. 

Heart-shaped Urchins, with inflated sides, the ambulacra on the upper surface lodged 
in depressions of the test; the mouth anterior between the centre and tlie border; the 
vent on the upper part of the posterior border in a direction oblique to that of the 
mouth. This name was changed by Klein, 1734, to 7§?fl/««^MS, adopted by Lamarck 
and all subsequent authors. As the genus Echinospatagm represents a natural family 
rather than a genus, one of the forms figured by Breynius among his types ought to 
bear this generic name, whilst the other genera might be readily arranged around the 
central type form. 



VI. G^KS— EcHiNOBRissus, Brepiius, 1732. 

Small buckler-shaped Urchins more or less depressed, the mouth-opening near the 
centre of the base, vent debouching into a deep dorsal sulcus, ambulacral areas petaloidal. 
The specimen figured as the type of this genus is one of the most common Oolitic forms. 
Still no author has cited this genus, and it appears to have been overlooked until Lamarck 
described it under the name Nucleolites. 



VII. Genus — Echinodiscus, _5rej/wzas, 1732. 

Discoidal Urchins with the mouth and vent opening near each other at the base. 
The ambulacra limited, petaloidal, and dorsal. Shell always flat ; border thin, entire, or 
often indented or perforated. This genus was adopted by Gaultieri, 1742, and by Seba, 
1758; by Leske and Davila, 1778. It was changed to Botula by Klein, 1734, and into 
Scutella by Lamarck, 1801. 

The ' Dissertatio Physica de Polythalamiis, de Belenmitis, de Echinis,' by Breynius, is 
a very scarce book. After endeavouring in vain to obtain it in commerce, I made known 
my want to my friend Professor de Koninck, of Liege, who kindly gave me the copy I 
now possess. In discussing many years ago the merits of this work with my old friend 
the Rev. Robert Hepworth, M.A., he kindly offered to make a translation for my Mono- 
graph of that portion of the dissertation which related to the classification of the Ecldno- 
dermata, for which I heai-tily thank him, and I have now the pleasure of adding the 
version as it came from his pen. I have inserted such references to the plates of this 
Monograph as will help the reader to supply the absence of the original plates which 
accompany the work of Breynius. 



DE ECHINIS. 193 



" De ECHINIS ET ECHINITIS, SIVE METHODICA EcHlNORUM DiSTRIBUTIONE, ScHEDIASMA 

JoANNis Philippi Breynii, M.D., ET SociET. Reg. Lond. Sodalis." 



" Genus I. — The Echinometra is an Echinus with the oral aperture placed in the centre 
of the base, hut icith the anal one diametrically opposite at the summit. 

The term Echinometra occurs in Aristotle, who designates by it the largest genus of 
Echini. Naturalists dispute whether, on this point, regard must be had to the size of 
the spines, or of the test. Bellonius and his followers determine the latter. Hence I 
think that this name is not inappropriately affixed to this Echinus, since those belonging 
to this genus are found equal in size to an infant's head. There is this additional 
peculiarity, that this genus, among all the Echini, is provided with very large spines and 
tubercles. Its common name is Ovarius. 

The Echinometra has many peculiarities which distinguish it from other Echini, 
besides the position of the apertures. 

1. Internally there are five testaceous teeth, each elaborately composed of several 
parts, and surrounded by testaceous semicircles, which are situated internally around the 
oral aperture. Some species of Echinanthus are also furnished with teeth, but of a 
different structure. 

2. The test is divided into five equal or nearly equal areas. 

3. Externally it is rendered rough by tubercles, greater or smaller according to regular 
series, placed for the purpose of receiving the sockets of the spines ; whilst in the other 
Echini all the tubercles are nearly equal in size and very small. 

4. In like manner it has the primary and secondary spines more or less large and 
unequal in size, whilst all the spines of other Echini are very small, and generally of 
equal size. 

5. I have also especially observed near the anal aperture a small warty substance [the 
madreporiform body], which can be more clearly distinguished with a lens, and similar to 
that which Linck first detected in the Star-fish, the use of which in that animal will 
doubtless throw light also upon this species of the Echinometra." 

[Plates V and VI of this work represent typical forms of this group.] 



25 



194 SCHEDIASMA 



" Genus II. — The Echinoconus ii an Echinus, whose ajiertures are lofh in the base, the 
oral in the centre, and the anal at or in the mar(ji7i. 

It is either of a conical figure (the Echinites pileatus of Luidius), or hemispherical, or 
more or less compressed or oval. All of them have five duplicate pointed Unes 
extending from the vertex to the oral aperture. 

I have observed various fossil species of this genus, but only one recent species. 

I have given it the name of Echinoconus from the conical figure which certain 
species possess. 

Table II, fig. 1. — The Echinoconus vere conicus ; perfectly conical, fossil; filled 
with cretaceous matter. From the Kent chalk pits. The Echinites pileatus, with either 
a conoid figure, or somewhat turbinated. [Plates XLIX and L of this work.] 

Pig. 2. The base of the same, in which may be observed the oral aperture in the 
centre and the anal in the margin. [Plate L, fig. 1. Echinoconus conicus, Brey.] 

Fig. 3. The Echinoconites hemisph^ricus ferme, nearly hemispherical, consisting 
of siliceous matter, or of what is commonly called hornstoue. [Plate LIII, fig. 2 c, (/.] 

Fig. 4. The base. [Plate LIII, fig. 2 b. Echinoconus subrotundus.'] 

Fig. 5. Echinoconus ovalis, the anal aperture near the margin. This is the only 
recent one known to me ; it does not exceed half an inch in size, is fragile, and with a 
whitish shell. 

Fig. 6. The base. 



Genus III. — The Echinocorys is an Echinus with both ajjertures in the base, the oral 
between the centre and the margin, and the anal as distant as possible from the 
moicth in the margin itself. 

All those which have come under my observation approximate in some measure in 
their form to that of a helmet. Hence they are termed by Luidius in his 'Litho- 
phylacium Britanuicum ' galeati or helmeted. 

I have designated the genus Echinocorys for the same reason, as Kopuc among the 
Greeks signified a helmet or casque. Hitherto I have observed no recent specimen of 
this genus, but many fossil ones. 

Table III, fig. 1. The Echinocorys vulgaris ; fossil, filled with cretaceous matter, 
from the chalk pits near Gravesend, Kent. This is the common helmeted Echinites 
of Luidius. 

Fig. 2. The base of the same, with two apertures; the upper one is the mouth, the 
lower the anus." 



DE ECHINIS. 195 

" Fig. 3. The Echinocoryta, like marble, ashy grey, representing with the greatest 
exactness the internal face of the shell. [This is a siliceous mould of an EcJdnoconus.'] 
Fig. 4. The base. [Siliceous mould of the base of a small Echimcorys vulgaris?^ 



Genus IV. — The Echinanthus is an EcMnus toJiose oral aperture is near the centre, 
and the aiial vpon or at that part of the margin iohich is at the greatest distance 
from the oral. 

All the species of this genus have an oval figure, one extremity of which is narrower, 
the other broader, in which latter the anal aperture is always situated ; but the poriferous 
zones in the upper surface resemble a five-petaled flower, as though they were artificially 
marked by a needle ; and for this reason I have assigned to this genus the name of 
Echinanthus or Urchin flower. 

It is termed by Woodward Echinus pentaphglloides, i. c., five-leaved, and is repre- 
sented as having only one foramen in the centre of the base ; whereas, on the contrary, 
the other foramen is conspicuous upon or at the margin in both the fossil and the recent 
species. 

Fig. 1. The Echinanthus, with the vertex (upper surface) more or less raised, of a 
whitish colour. F>om the Kleinian Museum. This species seems to approximate in the 
outward shape of an helmet to the Echinocorys, but it differs from it sufficiently in the 
position of the mouth, and in the likeness of the flower at the summit. 

Kg. 2. The base. This fossil Echinanthus, filled with chalky matter, is depicted in 
the ' Museum Amboinse,' Tab. LIX, fig. d. 

Fig. 3. An Echinanthus of flatter form ; fossil ; filled with stony matter. From Monte 
Baldo, near Verona ; remarkable for the upper surface Avith the anal aperture. 

Fig. 4. An Echinanthus with the dorsal region more or less raised along its length ; 
fossil ; filled with stony matter of an ashy colour. 

Fig. 5. The base. The oral aperture near the centre, the anal on the margin. In 
this genus the anal aperture is generally so situated that it can be viewed equally well 
from both the summit and the base. On this account I am the more astonished that 
Woodward should have overlooked it." 

[Plate LVIII, Pygurus lampas, represents a type form of this genus.] 



196 SCHEDIASMA 



"Genus V. — The Echinospatagus is an Echinus lohose oral aperture is between the centre 
and the margin, but the anal is situated obliquelj) oj^iposite to the mouth upon or 
at the margin towards the summit. 

The figiu-e is usually heart-shaped, the furrow being on the upper surface at the broader 
extremity ; or it is oval without a furrow of that kind. But the anal aperture is always 
observable in the narrow extremity, as in the Echinanthus. In some species there is also, 
it appears, some representation of a flower, as in my Echinanthus, but this consists not of 
fve but of only/o?(!r petals, and those of unequal size ; the fifth towards the broader 
extremity being absent. 

1 have thought that the name of Sjxitaf/us or Spatancjus, derived from the Greek 
Swarayyoc, and which is found in Aristotle and other naturalists who have thus desig- 
nated this Echinus, ought, on this account, to be retained, although more recent writers 
have extended the terra Spatagus or Spatanc/us to all except the oval Echini ; and these 
Woodward also has followed in his catalogue, which embraces under this title all except 
the oval and those marked with five leaves — the pentaphylloidal shaped. 

Table V, fig. 1. — The Echinospatagus cordiformis ; very common. The anal 
aperture which, in the entire shell, is usually closed l^ecause it is membranous, does not 
seem to be less minute than in the oval. I have found the shells of this genus empty, 
blanched, and very fragile. They are very commonly found on the shores of the Adriatic, 
near Pesaro, where they are termed Cut/lioni on account of their shape and size. 

Fig. 2. The base, in which may be observed both the oral aperture and the anal one 
of less size. 

Fig. 3. The heart-shaped Echinospatagus, more or less flat, of a smaller size ; fossil ; 
filled with chalk rock ; from, I believe, Wirtemberg. Fig. 4. The base. 

Fig. 5. The heart-shaped Echinospatagus ; fossil. English, from the Kent chalk pits. 
The Echinites cordatus of Luidius. [See Plate LXII, Micraster cor-anguinum?\ 

Fig. 6. The base. [Plate LXII, fig. 1 5.] 



Genus YI. — The Echinobrissus is an Echinus whose oral aperture usually occupies the 
centre of the base, but the anal is seen upon the upper surface at a short distance 
from the centre, and in a furrow obliquely opposite to the mouth. 

It is always of an oval shape, with the mouth invariably placed towards the narrower 
and the anus towards the broader part. Some species are rather more elevated, and 
represent in some measure the human buttocks ; hence it is called clunicularis by Luidius : 



. DE ECHINIS. 197 

but others with a flatter surface may be compared to a shield ; hence they are termed 
Echini clypeati. 

The Brissus (Bpfo-trog) is enumerated by Aristotle in his fifth book of the ' History 
of Animals ' as the tJiird genus of Echini. But since his translators have not sanctioned 
what this naturalist understood by that term, I have applied the name of Brissus to this 
genus. 

No recent Echinobrissus has come under my observation, but I have seen some fossil 
species, although these latter are by no means common. Morton assigns only one aperture 
to this Echinus, since the other situated in the furrow escaped his notice ; but Woodward 
ought afterwards to have discovered it, since he enumerates it among the Echini which 
have two apertures, the other being in the furrow. 

Table VI, fig. 1. The Echinobrissus planior or Clypeatus minimusj fossil; filled 
with stony matter ; with the anal aperture in the furrow. From England. [Echino- 
brissus clunicularis.'\ 

Fig. 2. The base with the oral aperture. 

Fig. 3. Echinobrissus ELATIOR ; more or less raised ; fossil; filled with stony matter. 
From England. [Echinobrissus scutatus, a characteristic fossil of the Coralline Oolite.] 

[Plate LVI, figs. 1 and 2 represent several type forms of Echinobrissi from the Creta- 
ceous formations. This genus has one living representative species.] 



Genus VII. — The Echinodiscus is an Echinus with the oral aperture situated near the 
centre, but ivith the anal between the centre and the margin or on the margin. 
The form always somewhat flattened. 

All the species of this genus have the likeness of a five-leaved flower upon the upper 
surface. 

I have termed it Echinodiscus from the figure of a disc or orb. 

As I have not seen any recent Echinus of the genus iumiediately preceding, so, on the 
other hand, I have never hitherto observed a fossil of this genus. The foUowing species 
were all brought from the Eastern Ocean. 

Table VII, fig. 1. The Echinodiscus circinatus minor, with the margin entire. 

Fig. 2. The base or lower portion, in which is seen the anal aperture, but the other 
(the oral) in the middle is not visible on account of the mutilation of the shell in the 
centre. 

Fig. 3. Echinodiscus, one half of the circumference generally marked with equal 
indentations. 

Fig. 4. The base, in which are seen the oral and anal apertures." 



198 ECHINOCONIDtE. 

"Fig. 5. All EcJiinodiscus, one half of the circumference marked with unequal indenta- 
tions. The other half furnished with two pervious apertures. 

Fig. 0. The base, with mouth and anus. 

Fig. 7. The Echinodiscus aiaximus, with margin entire. The anal aperture placed 
on the margin itself. From the Kleinian Museum. 

Fig. 8. The base, with the oral aperture in the centre. 

A new genus may not inaptly be constituted as the eighth in order in my 
' System,' from this last species, since it differs as to the rule of the position of the anal 
aperture, and in the absence of the representation of the flower. But since only this 
single species has been known hitherto, I have preferred adding it to the EcJiiuodisci, 
until perchance some other specimen shall have been discovered." 

[I must refer all interested in the study of this group to Professor L. Agassiz's 
admirable Monograph ' Des Scutelles,' with magnificent plates of living and fossil forms. 
T. W.] 



VI. Famili/ — Echinoconid^, Wright, 1854. 

^Vlien I proposed the establishment of this Family I defined it as a natural group of 
fossil Eclihioidea having a thin, circular, or slightly pentagonal test ; the upper surface 
in most of the forms being very much elevated or conoidal, in others it is more or less 
depressed. 

The ambidacral areas are narrow and the inter-ambulacral wide ; the plates of both 
are covered with numerous, small, perforated tubercles, raised on bosses with crenulated 
summits. They are sometimes scattered over the plate, but are frequently arranged in 
regular longitudinal rows. They are always larger at the base than on the sides and 
dorsum ; and the surface of the test is likewise covered with close-set microscopic 
granules. 

The poriferous zones are narrow, and formed throughout of round unigeminal pores 
about equal in diameter; they converge in a straight line from the apical disc to the 
peristome, around which aperture they have sometimes a bigeminal arrangement. 

The mouth-opening is inferior, central, sub-circular, and armed with five pairs of jaws ; 
the peristome is more or less decagonal and divided by notches into ten lobes, well 
marked in Pijcjaster and Holed i/jms, but feebly in Discoidea and Echinoconus. 

The vent is variable in position ; it is situated at the upper surface in Py(jaster, at the 
border in Echinoconus, at the base in Discoidea ; and this "aperture is oval, pyriform, or 
oblique in different genera. 

The apical disc occupies the summit of the upper smface, and is composed of five ovarial 
and five ocular plates ; the madreporiform body is very large, extending from the right 
antero-lateral ovarial into the centre of the disc. 



ECHINOCONID^. 199 

The posterior ovarial is often replaced by a complementary, imperforate plate, which 
is sometimes wanting altogether. 

The spines are small, short, and subulate. 

The EcHiNocoNiDyE are distinguished from the Echinobrissid.e, Echinolampid^, 
and Clypeasterid^, by their simple poriferous zones ; in this respect the family 
resembles the Echinonid^, from which, however, it differs in possessing a peristome 
furnished with auricles and a masticating apparatus ; the form is likewise more circular 
and elevated, and the tubercles are more developed and arranged in longitudinal rows. 

The EchinoconiDjE are an extinct family, found only in the Oolitic and Cretaceous 
rocks; at present we recognise six well-defined genera in this natural group, which 
present the following opposite characters : 

Test elevated ; ambitus with projecting internal septa ; vent 

inferior always ..... Discoidea. 

Test elevated ; peristome sub-decagonal ; vent marginal . Echinoconus. 

Test depressed ; ambitus without internal septa ; vent inferior 

and marginal ..... Holectypus. 

Test depressed ; peristome decagonal ; vent oblique, distant from 

the disc ; tubercles perforated and crenulated , . Anorthopygus. 

Test depressed ; peristome decagonal ; vent pyriform, separated 
from the disc; tubercles perforated, but not crenulated; 
irregularly superposed pores . . . Pileus. • 

Test depressed ; peristome decagonal; vent pyriform, not separated 
from the disc ; tubercles perforated and not crenulated ; pores 
xmigeminal, regularly superposed . . . Pygaster. 



I. Gemis — Discoidea, Klein, 1734. 

Galekites, pars, Lamarck, 1801. Discoidea, Gray, 1834. Discoidea, Agassiz, 1836. 

Discoidea, Desor, 1842. 

Test circular or subpentagonal at the border ; upper surface much elevated, hemi- 
spherical ; sides vertical or slightly convex ; inferior surface flat, slightly concave. 

Poriferous zones very narrow, and converging in a straight line from the disc to the 
peristome. 



200 DISCOIDEA. 

Tubercles very small, perforated, creniilated, and surrounded by areolae, unequal and 
microscopic on the sides and upper surface; larger at the ambitus and base, and disposed 
there in regular concentric rows. 

Mouth-opening small, circular, central ; peristome decagonal, marked by slight notches. 

Vent inferior, oval, sub-acuminate at both extremities, situated between the peristome 
and posterior border; opening covered with irregular granular plates, which are very 
small around the anal opening ; this aperture is placed near the internal angle. 

The apical disc solid, well soldered to the areal plates, and forming a slight projection 
above the test, having in some five perforated ovarial plates, in others four perforated 
ovarials, and an imperforate, complementary, single ovarial ; raadreporiform body resting 
on the larger antero-lateral, and extending into the centre of the disc ; ocular plates small 
and well wedged into the angles of the ovarials. 

From the inner surface of the inter-ambulacral plates near the poriferous zones thick 
shelly processes project inwards, and form internal septa, which occasion the ten charac- 
teristic impressions near the ambitus seen on the moulds of this genus. 

Spines short, stout. 

The Biscoidea very much resemble Holedijpus. Prof. Desor properly separated 
the latter from the former in consequence of the absence of all internal ribs from the shell 
of Holectypus, which likewise has a larger mouth-opening, the peristome deeper notched, 
and the vent often marginal. 



o 



A. — Species from the Upjjer Greenscmd. 
DiscoiDEA SUBUCULUS, Klein, 1734. Plate XLV, figs. 4, 5, 6. 

DiscoiDES SUBUCULUA, Klein. Nat. dispositio Echinodermatum, p. 26, pi. xiv, 

I, m, 1734. 
EcHiNiTES SUBUCULUS, Leslce, apud Klein, p. 171, pi. xiv, /, ?n, n, o, 1778. 

— — Gmelin. Systema Nature, p. 3183, 1789. 

— — ■■ Encyclop. metliod., Moll, et Zoophyt. Atlas, pi. 158, figs. 

14, 15, 1791. 
DiscoiDEA SUBUCULUS, JBarkinsoH. Organic Eemains, toI. iii, p. 21, 1811. 

EcHiNiTES, Smith. Strata Ident. by Organ. Foss., pi. vii, fig. 12, 

1816. 
Galekites kotulaeis, Lamarck. Animaux sans Yert., t. iii, p. 21, 181 1. 

— — Deslongchamps. Zoopb., Encyl. method., t. ii, p. 433, 

1824. 

— — Befrance. Galerites, Die. Sc. Nat., t. xviii, p. 86, 1825. 
Galerites SUBUCULUS, Goldfuss. Petref. Germanise, t. i, p. 129, pi. xlix, fig. 2, 

1826. 
EcHiNONEUS KOTULARis, BlainvUle. Zoopb., Die. Sc. Nat., t. Ix, p. 194, 1830. 
DiscoiDEA SUBUCULUS, Bronn. Lethsea Geogn., p. 615, pi. xxix, fig. 19, 1835. 

— ROTULAKis, Agassi:. Prodrome d'une Monogr., p, 186, 1836. 



FROM THE UPPER GREENSAND. 201 

Galerites hemisph^eeicus, Grateloup. Mem. les Oursins Fossiles, p. 55, 1836. 

— sxTBCCULUs, Besmoulins. fitudes sur les Echinides, p. 254, 1836. 
DiscoiDEA STJBUCULUS, Besor. Monogr. des Galerites, p. 54, pi. vii, figs. 5 — 7, 

1842. 

— — Morris. Catalogue of British Fossils, p. 52, 1843. 

— — Agassi: and Desor. Catal. rais. des Ech., Ann. Sc. Nat. 

3e serie, t. vii, p. 146, 1847. 

— — A. Gras. Oursins fossiles de I'lsere, p. 44, 1848. 

— — Bronn. Index Palseontologicus, p. 430, 1848. 
Galerites subuculus, Forbes. Mem. Geol. Surv., Dec. 1, pi. vii, 1849. 
DiscoiDEA SUBUCULUS, d'Orbigny. Prod, de Pal. Strat., t. ii, p. 179, 1850. 

— — Sorignet. Oursins fossiles de I'Eure, p. 39, 1850. 
Galerites subuculus, Forbes in Dixon's Geology of Sussex, p. 341, 1852. 
DiscoiDEA SUBUCULUS, Forbes in Morris's Catalogue of Brit. Fossils, 2ud ed., 

p. 77, 1854. 

— — Desor. Synop des Echinides Foss., p. 1/6, pi. sxiv, 

fig. 1, 1857. 

— — Cotteau and Triger. Ecliinides Foss. de la Sarthe, 

p. 170, pi. xxiv, fig. 12, 1859. 

— — Cotteau. Paleontologie Fran^aise, Ter. Cretace, t. vii, p. 

23, pi. 1009, fig. 8—16, 1864. 

— — Be Loriol. Oursins de la Suisse, pi. xiii, fig. 15, 1873. 

Dict(/)iosis. — Test small, circular, or slightly pentagonal ; upper surface inflated, more 
or less conical ; under surface concave in the middle ; ambulacra forming five prominent 
bands, composed of very narrow plates ; poriferous zones narrow, straight, holes 
imigeminal in oblique pairs. Interambulacra wide, divided into three lobes by two sub- 
central carinse, which rise from near the middle of the plates ; miliary zone concave, 
depressed ; tubercles small, perforated, larger at the base ; on the sides there are two 
regular, constant, carinal rows, and eight or ten less regular and inconstant ; at the base 
the principal tubercles are arranged in concentric lines around the peristome. Surface of 
all the plates covered with fine close-set granulations ; mouth-opening small, sunk in the 
middle of a deep depression; vent infra-marginal, pyriform, midway between the 
peristome and border, with the apex directed inwards. Apical disc small, prominent, 
composed of five ovarial and five very small ocular plates. 

Bimensions. — Height, seven twentieths of an inch ; latitude, eleven twentieths of an 
inch. The relative proportion of height to breadth varies considerably in different 
specimens. 

Description. — A figure given by Plott^ in his ' History of Oxfordshire,' pi. viii, fig. 9, 
and described as "another sort of Button-stone, sent me from Teynton, which I take to be 
a mere production of nature, finely striated from the top, as I have seen some hair buttons, 
as in Eig. 9, and may therefore be called Porpites .- except we should rather take it for a new 
sort of EcJdnites not yet discovered, which is wholly left to the reader's choice." Martin 

> ' The Natural History of Oxfordshire,' ed. 1677, pi. viii, fig. 9, p. 139. 

26 



202 DISCOIDEA 

Lister' in his ' Hist. Animal. Angliae ' states, in reference to his fig. 20, tab. vii, which is 
copied from Plott, " Echinites parvulus striis capillaceis undiq ; insignitus," ex D. Plott, 
fig. 9, tab. viii, " Juxta Teynton agri Oxoniensis inventus est." 

Lang,2 in his ' Historia Lapidum Figm-atorum,' says, in reference to " Echinites, striis 
capillaceis a centro ad circumferentiam undique insignitus, subluteus mediocris rotundus, 
vertice compresso, basi ex pluribus annuUs striatis sibi invicem impositis conflata." I 
regard the original of Plott's figure not as an Echinite, but as a species of Coral belonging 
to the family Ci'CLOLiTiDiE, genus Anabacia; about Lang's figure I think there can be no 
doubt, the concentric ridges of the epitheca at the base afford sufficient evidence of the 
class Anthozoa to which his fossil Coral belonged. Klein's ' Naturalis Dispositio ' is the 
first work^ in which we find an undeniable figure of this Urchin ; in tab. xiv, /, m, n, o, he 
says, " Discoides siibuculus ; Kamisol-Knopff: Discum Germanorum imitans, si versum vel 
supinum consideramus, a Vertice rosacea ; quiuque seriebus geminis capillaceis et velut 
acu pictis; in vertice figuram rosulag ferens." Leske,' in his 'Additamenta ad Kleinii 
Echinodermata,' observes, in reference to the figure given by Plott and Lister, " pro 
Echinite exhibetur ; at vero quantum ex icone coniicere licet, potius Madreporites est, quam 
Echinites. Nam striae capillaceas ex centro progrediunter, ut in Madreporis, neque aliqua 
oris vel ani mentio fit, prajterea a Plotio Porpites dicitur, quod ipsum nomen Madreporis 
petrefactis tribui solet. Tanquam dubium corpus, illud itaque omisi." Of Lang's figure 
Leske says, " mea sententia firma manet, hsec corpora non Echinitas, sed jMadreporitas esse." 

The figures of this Urchin given by Parkinson of English specimens, and by Brongniart of 
French, are very poor; and those of Bronn and Goldfuss of German forms, are not satisfactory. 
The first real good drawing is that given by Professor Desor in his valuable ' Monograph 
on the Galerites,' and since then Professor E. Forbes' beautiful plate of this species in the 
'Memoirs of the Geological Survey,' decade 1, pi. vii, leaves nothing to be desired; 
subsequently admirable figures have been pubUshed in the ' Paleontologie Francaise, 
Terrain Cretace,' and in the Echinides of the department of the Sarthe, by M. Cotteau. 

The test is small, orbicular, or slightly pentagonal, the upper sm-face convex, more or 
less conical, and divided into five broad and five narrow segments by the poriferous zones, 
Avhicli radiate with mathematical accuracy from the circumference of the apical disc, which 
is small and prominent at the vertex. The imder surface is rounded in young and 
concave in adult specimens, the small, circular mouth-opening hes in a deep central 
depression, and between it and the posterior margin is a large oblong vent. 

The inter-ambulacral areas at the ambitus are nearly twice the width of the ambulacral ; 
the dorsal surface of large specimens contains thii'teen plates in each column between the 
apical disc and the basal angle ; the length of the plate varies from the ambitus, where 

1 ' Historia Auimalium Angliae,' 16/8, tab. vii, fig. 20, p. 220. 

2 'Historia Lapidum Figuratorum Helvetise,' 1708, tab. 36, figs. 1, 2, p. 126. 
5 'Naturalis Dispositio Echiuodermatum,' 1734, tab. xiv, sec. 57, p. 26. 

* Ibid., Additamenta ad Kleiuii, 1778, p. 172. 



FROM THE UPPER GREENSAND. 203 

they are longest, to tlie apex, where they are shortest, but their vertical depth is nearly 
the same throughout ; their surface is thickly covered with minute secondary granules 
placed in very regular horizontal rows (fig. 4y). Each plate exhibits a more or less 
distinct sub-central carination, so that in many specimens the inter-ambulacral areas 
appear to be partitioned by two prominent ridges on each side of the line of junction of the 
plates. Along the carinated ridge each plate develops a larger tubercle, and these form a 
complete series from the base to the summit (figs. 4, a, h, d, (/) : between this and the 
median suture there are two smaller tubercles placed horizontally (fig. 4^), and between 
the carina and the poriferous zones are two or more similar tubercles placed in 
two oblique series with reference to the larger central tubercles on the line of carina- 
tion ; consequently the primary tubercles placed between the carinated ridge and the 
median suture are horizontal, and those between the ridge and the zones arranged in 
obhque rows (fig. 4). At the ambitus the tubercles are more numerous and less regu- 
larly disposed. The basal plates resemble very much those on the upper surface ; in 
full-grown specimens they are from six to eight in number; they are of the same ver- 
tical depth as those on the dorsal surface, and are ornamented in a like manner. 

The ambulacral areas are half the width of the inter-ambulacral; the plates are 
numerous and narrow, four plates occupying the vertical depth of one inter-ambulacral 
plate (fig. 4 g) ; they are closely covered with small granulets, and each plate supports a 
small primary tubercle. These tubercles are so placed that they form oblique rows of twos 
or threes, and do not form direct vertical rows. The plates forming the ventral portion 
of the areas are rather larger than those on the dorsal surface (fig. 4 c). 

The poriferous zones are straight and extremely narrow ; the pores are unigeminal, 
and the pores of each pair are obliquely placed (fig. 4 //, g). Each inter-ambulacral 
column contains twenty-one plates, and each ambulacral column eighty-four, and 
there are one pair of pores opposite each plate; it follows that each zone contains 
eighty-four pairs of pores ; all the primary tubercles are raised on elevated bosses in 
areolar spaces, and they are ail perforated (figs. ^f,g, A)- 

The apical disc is small, and makes a slight prominence at the vertex ; the right 
antero-lateral plate is the largest, and supports a large madreporiform body (fig. 4 e) ; the 
single ovarian plate is imperforate, as in all its congeners. The ocular plates are very 
small, and closely fitted in between the ovarials. 

The mouth is circular, and occupies a deep depression in the centre of the under 
surface ; it is about one fourth the diameter of the base ; the peristome is feebly 
decagonal, and the lobes are nearly equal (fig. 4 c). 

The vent occupies a considerable portion of the basal region in the single inter-ambu- 
lacrum, between the peristome and the border ; it is of a pyriforni shape, having its small 
extremity directed inwards towards the mouth with a series of tubercles surrounding it 
(fig. 4 c). 

Like other Discoidea, moulds of the interior diff'er materially from the external shape 



204 DISCOIDEA 

of the test in exhibiting ten notches around the margin, extending to the mouth on the 
ventral surface, and disappearing at the lower third of the dorsal. Five of these unite 
near the mouth, and five continue singly to it. The centre of the prominent interspaces 
of the latter is marked by a shallow depression. This groove corresponds to the line of 
suture of the ambulacral plates, and its prominent sides to the pores. The ten deep 
notches are caused by as many internal ribs, which spring from the inner sides of the 
mouth, and run up the wall under the carinated portion of each series of inter-ambulacral 
plates . " — Forbes. 

Affinities and Differences. — x\fter a careful comparison of B. subuculus with the four 
following allied species, the late Professor Forbes remarks •} — The first, Discoidea minima, 
Agass., founded on a single example from the Chalk-marl of France, appears to be only 
one of the less conical forms of the young of the species, such as not uncommonly occur 
at Warminster. The second, D. fisum, Merian, is said to be exactly like B. minima, and 
only distinguishable from it and B. siihucuhis by having distinctly perforate primary 
tubercles ; this, however, is a generic and not a specific character. The third, B. turrita, 
Desor, is proportionally higher than B. subuculus. The fourth, B. infera, Desor, has 
primary tubercles only at the base. I have little doubt, the Professor observes, that the 
several so-called species just enumerated are only slight varieties, if as much, of B. sub- 
uculus. M. Cotteau admits that B. pisum may be the young of B. subuculus, but that the 
three others indicated by Professor Forbes are certainly distinct. B. subuculus differs 
from B. Bixoni,Yox\i.,m having smaller mouth- and vent-openings, so that the appearance 
of the base is materially different. 

Locality and Sfratit/raphical Position. — This Urchin is abundant in the Upper Green- 
sand of Warminster, and Chute Farm, Wilts ; in the junction beds of Greensand and 
Chalk-marl at ]\Iaiden Bradley, Wilts ; the Lower Chalk at Weymouth, and the Grey 
Chalk near Folkestone. This species is very abundant in the different type localities of 
the Etage Cenomanien in France, see p. 189. 

B. — Species from the Lower Chalk. 
Discoidea cylindrica, Lamarck's sp. PI. XLVI, figs. 1,2; PI. XLVII, figs. 1 — 3. 

Galeeites cylindricus, Lamarck. Aniniaux sans Vertebres, torn, iii, 

p. 23, 1816. 
— — Beslongchamps. Encycl. Method., Zoophytes, 

t. ii, p. 433, 182-1. 
CoNCLUS Haavkixsii, Mantell. Geol. Trans., new series, vol. iii, 

parti, p. 208, 1828. 
Galeeites canalicdlatus, Goldfuss. Petrefacta GermauiEe, vol. i, p. 128, 

pi. xli, 1829. 

' ' Memoirs of the Geological Survey,' Decade 1, pi. vii, p. 4. 



FROM THE LOWER CHALK. 



203 



scutella depressa, 

hemispherica, 

discoidea canaliculata, 

Galerites Hawkinsii, 

discoidea cylindeica, 

Galerites cylindkicus, 

DiSCOIDEA CYLINDRICA, 



HEMISPHERICA, 
CYLINDRICA, 



Woodward. Geology of Norfolk, p. 52, pi. v, 

%. 4, 1833. 
Woodward. Idem, pi. v, fig. 5, 1833. 
Agassis. Prodrome, Mem. Sc. Nat. Neuchatel, 

t. i, p. 186, 1836. 
Besmoulins. Etudes sur les Ecbiiiides, p. 254, 

1837. 
Agassiz. Echinid. foss. de la Suisse, Part I, 

p. 92, pi. vi, figs. 13—15, 1839. 
Bujardin. Animaux sans Vertebres 2e ed., t. 

iii, p. 311, 1840. 
Besor. Monogr.iphie des Galerites, pi. viii, figs. 

8—16, p. 58, 1840. 
Morris. Catalogue of British Fossils, p. 52, 1843. 
Morris. Idem. 
Agassiz et Desor. Catal. rais. les Ecb. An 

Sc. Nat. 3e ser., t. vii, p. 147. 1847. 

— — Bronn. Index Palseontologicus, p. 429, 1848. 
Galerites (discoidea) cylindricus, Forbes. Mem. of Geol. Surv., Decade 1, pi. viii, 

1849. 
d'Orhigmj. Prod, de Pal. strat., t. ii, p. 178, 1850. 
Quenstedt. Hand, der Petrefact., pi. xl, fig. 20, 

p. 583, 1852. 
Gras. Catal. Ours. foss. de I'lsere, p. 43, 1852. 

— — Morris. Catal. Brit. Foss., 2 ed., p. 77, 1854. 

— — Pictel. Traite de Paleont., t. iv, p. 228, pi. 

xcv, figs. 9—12, 1857. 

— — Besor. Synopsis des fichinides Fossiles, p. 177, 

pi. xxix, fig. 12, 1857. 

— — Cotteau. Paleont. Fran^aise, Ter. Cret., t. vii, 

p. 28, pi. 1010 et 1011, 18(36. 

— — BeLoriol. Ours, de la Suisse, pi. xiii, fig. 14, 1873. 

Biapiosis. — Test large, sub-circular, slightly pentagonal ; upper surface hemispherical, 
more or less elevated, regularly convex above, rounded vertically on the sides, and acutely 
angular at the border ; base nearly flat, marked by impressions which correspond to the 
internal carina ; ambulacra one third the width of inter-ambulacra ; mouth-opening 
central, decagonal ; vent small, oblong, basal, midway between the peristome and border. 

Dimensions. — a. Height, one inch and four tenths ; latitude, two inches and one tenth, 

B. Height, one inch and eight tenths ; latitude, two inches and two tenths. 

Description. — Whether this' common Chalk Urchin was known to Leske or not is 
difficult to decide. My friend Professor Desor considers the notice on Echinus quater- 
fasciatus to refer to this species ; but a careful examination of Leske's figures leads me to 
the conclusion that the mouth figured by that author in his PI. xlvii represents some 
■species of the genus Echinoconus rather than a Discoidea, for they show no trace of 



discoidea cylindrica, 
Galerites cylindricus, 

Discoidea cylindrica, 



206 DISCOIDEA 

impressions made bj' the internal ribs, so characteristic of the latter genus. For this 
reason I am of opinion that the history of this Urcliin commences with Lamarck's description. 

The outline of Discoidea ci/K7idrica is orbicular, the base is very flat, and the upper 
surface convex, more or less elevated, the amount varying with its phases of growth from 
a regularly hemispherical form in young shells, as in the specimen figured in PI. XLVI, 
fig. 2 a, to hemispherico-cylindrical, its adult condition, as shown in PI. XLVI, fig. 1 c, 
and PI. XLVII, fig. 1 a, h. 

The inter-ambulacral areas are three times the width of the ambulacral (fig. 1 a, h,d); 
the plates on the sides and lower part of the dorsal surface are broad horizontally and 
narrow vertically (fig. 1 f/), and those around the vertex are nearly square (fig. 1 e) ; 
near the middle of each plate there is a slight elevation of the surface which, in connection 
with others in the column of plates, form a line of carination, which extends from the 
apical disc to the circumference, and imparts a marked feature to some old tests (PI. 
XLVII, fig. 1). On this ridge a tubercle rather larger than the others is developed 
(fig. 1 d) on the lower half of each plate ; (this tubercle with the line of carination is indi- 
cated in fig. 1 dhy the vertical shading). On the surface of each plate from the sides of 
the test there are from six to seven larger, and the same number of smaller tubercles 
(fig. 1 d), all of which are perforated and striated, and their areolar spaces surrounded 
by circles of minute granules (fig. 2d); the quadrate plates in the upper portion of the 
columns support only the one tubercle growing on the line of carinations already referred 
to (fig. 1 e). In addition to the perforated and striated tubercles, the plates are covered 
with microscopic granules, distributed very regularly over the surface. The series of 
plates around the angular border are narrow, and bear five or six large tubercles 
arranged in regular horizontal rows, having areolar excavations aroimd their base. Those 
on the basal plates are still more conspicuously ornamented with rows of primary tuber- 
cles, each surrounded by a depressed areola bounded ])y granules, which are larger and 
more thickly set than on the upper surface. The plates round the mouth are smaller and 
have fewer tubercles (fig. 1 b). The inferior inter-ambulacral plates bulge out on each 
half near the margin, a prominence which is continuous with the lines of carination above, 
and indicates the position of the internal ribs in the interior of the test. PI. XLVII, 
fig. 2 a, b, shows the position of impressions made by the internal ribs on a well-marked 
mould ; from this we learn that the two impressions at the base of each inter-ambulacra, 
and the ridge at the circumference, are due in part to the internal ribs of the test. 

The ambulacral areas are narrow and lanceolate above, and of the same width and 
more prominent at the base ; they are composed of small unequal plates, of which about 
three correspond vertically to one inter-ambulacral plate. They are, however, very 
irregular in size and shape, some being narrow, others rhomboidal or triangular, with 
small wedge-shaped pieces fitted into the poriferous zones, the whole forming a kind of 
mosaic of many-sized pieces. The plates at the base and on the upper surface are more 
regular in form and smaller in size than those on the sides (fig. Id); each plate carries 



FROM THE LOWER CHALK. 207 

one or two small primary tubercles ; at every thiixl plate one of these is near the zonal 
side (fig. 2/), so that in each ambulacra there are two marginal rows of small perforated 
and crenulated tubercles surrounded by several microscopic granules. 

The poriferous zones are very narrow, and liave one pair of small round holes opposite 
each ambulacral plate, which are larger and more conspicuous on the dorsal than on 
the ventral surface ; on the lateral and dorsal surfaces the pores are unigeminal, but at 
the base, from the narrowness of the plates, they fall into doable file (fig. 2/), and near the 
mouth-opening two rows go to each plate, the numl)er of pairs of pores corresponding 
with the number of the ambulacral plates ; taking the average as equal to seven ambulacral 
plates for two inter-ambulacral an average-sized adult test would have seventy pairs of 
pores in the lateral and dorsal portions of the zones ; the exact number at the base it would 
be difficult to estimate, from the narrowness of the plates and the bigeminal arrangement 
of the pores. 

The base is flat and the mouth-opening occupies the centre of the disc ; it is a small 
obscurely decagonal opening (PL XL VI, figs. 1 5, 2 b), equal in diameter to one fourth the 
distance between it and the border ; the peristome is subcircular and divided into ten 
equal lobes ; it is only in some rare specimens that this part of the anatomy of the test is 
shown, as the oral opening is nearly always filled with closely adhering matrix. Li 
some fine specimens from the soft Grey Chalk I have been able to clear out the peristome 
and demonstrate the oral lobes. 

The vent is proportionately very small, oblong, and acute at each extremity. It 
occupies rather more than one fourth of the space between the mouth and border, 
and is distant from the margin about its own long diameter (fig. li^). The plates of the 
single inter-ambulacrum appear sharply incised by the vent, the margins of which are on 
a level with them except at the inner extremity, where there is a bulging of the plates 
extending to the peristome (PL XLVII, fig. \b). 

The apical disc is well shown in my type-specimen ; and this structure is accurately 
drawn in PL XLVI, fig. 2 c. It is often prominent in consequence of the convexity of 
its elements ; the five ovarial plates are of an irregular rhomboidal figure and closely united 
together ; four of the five plates are perforated for the passage of the genital tubes, the 
single plate is imperforate, and the microscopic madreporiform body occupies the entire 
surface of the right antero-lateral plate. The five ocular plates, each having an orbit, 
are small cordate bodies wedged into the angles of the ovarials, fig. 2 c shows this 
structure magnified six diameters. Mr. Bones' very accurate drawing renders any 
lengthened description of the discal elements unnecessary. 

In PL XLVII, fig. 2 a, b,l have figured a very perfect mould of this Urchin to assist 
the geologist to identify the species when all the test is absent. This mould is marked by 
ten impressions made by the internal carinse of the test, which deeply groove the border 
and base and extend from the lower part of the sides, pass along the floor of the test and 
vanish at the peristome. In addition to these well-marked depressions Professor 



20S DISCOIDEA 

Desor describes and figures three fine marginal incisions nsible below and in profile in 
each cohimn of plates, and which assume a different form in the single inter-ambulacrum 
where they are only two in each column ; they are here wider and deeper than those in 
the pairs of the inter-ambulacra. 

PI. XLVII, fig. 3, is the drawing of the base of a mould of a monstrosity of this 
species, in which there are only four ambulacra seen from below. 

Affinities and Differences. — Blscoidea cylindrica cannot be mistaken for any of its 
congeners, as it is readily identified by its great height, its inflated and sub-cylindrical 
form, its perfectly flat base, and by the proportionate smallness of the oral opening and 
the vent. Biscoidea Favrina is the nearest allied form ; this, however, differs from 
D. cylindrica in having a larger vent placed nearer the border, and in having the iuter- 
ambulacral plates much larger ; each plate, in vertical height, corresponding to six 
ambulacral plates. 

Local if 1/ and Siratigrapldcal Position. — This species occurs in the Upper Chalk of 
Norwich and Holt (Mr. S. Woodward, Sen-), Chalk Marl and Lower Chalk at Hamsey, 
near Guildford, Markham Gayton, Charing, Lewes, Dover, Burham, near Maidstone, 
Speeton, Yorkshire ; the Chloritic Marl, near Chardstock, and in the Red Chalk, in the 
highest of the tinted bands at Speeton CliS", Yorkshire, at the part where the pink and 
white sems alternate (Rev. T. Wiltshire). 

Foreign Distribution. — In France, in the ' Etage Cenomanien,' according to M. 
Cotteau, Rouen (Seine-Inferieure) ; Pourrain, Saint-Sauveur (Yonne) ; La Fauge pres le 
Villard-de-Lans (Isere) ; Saint-Aignan en Vercors (Drome) ; Castellanne (Basses-Alpes). 
Lr Germany, in the Lower Planer (stage with Ammonites BJiotomagensis) = Chalk-marl 
of English authors ; at Langelsheim near Brunswick (Strombeck) ; at Rethen, near Hilde- 
sheim (Romer), near Paderborn (Goldfuss), from the Gault of the Mountain of Fis, 
according to Desor, and from the Etage Albien, Cheville, Alpes Vaudoises = Lower 
Chalk (Renevier). 

DiscoiDEA MINIMA, Agassiz, 1840. PI. XLVII, fig. 4 a — h. 

DiscoiDEA MINIMA, Agassiz. Catal. S3'st. Ectyp. Foss., p. 7, 1840. 

— — Desor. Monogr. des Galerites, p. 56, pi. viii, figs. 1 — 4, 1842. 

— — Morris. Catalogue of^Britisli Fossils, p. 52, 1843. 

— — Agassi: and Desor. Catal. raisonne des llchinides, 1847. 

— — Morris. Catalogue of British Fossils, p. 77, 2nd ed., 1854. 

— — McCoy. Contributions to British Palaeontology, p. 67, 1854. 
_ _ Cotteau. Paleontol. Fran9aise, t. vii, pi. 1012, figs. 1—7, 186G. 

Diagnosis. — Test small, sub-circular ; height and length equal ; upper surface 
inflated ; base slightly convex ; border round ; ambulacra half the width of the inter- 
ambulacra; tubercles form regular series on the sides of the areas; mouth and vent 
moderately wide. 



FROM THE UPPER GREENSAND. 209 

Description. — The specimens of this Urchin sent to me for drawing and description 
were so imperfect that I requested Mr. Bone to make accurate copies of the very capital 
figures of this species given by my friend M. Cotteau in the ' Paleontologie Fran9aise,* 
pi. 1012, figs. 1—7. 

The test is small and sub-circular ; the upper surface inflated and convex ; the 
base slightly swollen in the middle, and round at the border. 

The ambulacra half the width of the inter-ambulacra, with two rows of primary 
tubercles extending from the disc to the peristome (fig. 4 r/, h) ; the plates supporting, 
besides, numerous fine granules, which are disposed around the base of the tubercles. 
The poriferous zones are narrow, the pores round, unigeminal, slightly oblique, and well 
spaced out from each other (fig. 4/ and fig. 4 ff). 

The inter-ambulacra are formed of large plates ; at the ambitus each plate carries 
three tubercles, two of which are more conspicuous and persistent than the others, and 
reach higher up the sides. The central tubercles extend from the disc to the peristome, 
and the zonal series is absent above and below ; the larger tubercles grow on two slightly 
elevated longitudinal carinal lines (fig. 4/), indicated by the direction of the shading in 
the figures. The granulations on the plates are very fine and form horizontal beaded 
chains of great delicacy ; the primary tubercles at their base have circular depressed 
areolas without encircling granulations. 

The small mouth-opening has a circular or sub-decagonal peristome and opens in the 
centre of the base, which is shghtly convex (fig. 4 a). 

The vent is oval, and acuminated at the inner extremity ; it occupies nearly two 
thirds of the space between the peristome and posterior border ; the aperture was closed 
by a series of ten anal plates, unequal in size (fig. 4 h) and covered with small granules ; 
the periprocte at the inner border is surrounded by seven small plates let into a space 
around the vent like a piece of mosaic. 

The apical disc is small and composed of five perforated ovarial plates, the right 
antero-lateral being much the largest and covered with the madreporiform body ; the 
surface of the other four is crowded with granules ; and the small cordate oculars are 
wedged into the angles formed by the ovarial plates. 

Jffinities and Differences. — The general form and arrangement of the tubercles on 
D. minima resemble the young condition of D. subucuhts, of which some authors 
consider it a small variety. M. Cotteau^ has had an opportunity of examining with care a 
great number of specimens collected from different localities, and says that he has 
acquired the certainty that this species differs essentially from D. subuculus, not only in 
its size, which is constantly smaller, but in its greater height, more inflated sides, and 
convex base, and by its granules, which ai'e more closely set together and disposed in 
more regular lines on the plates, and always by its apical disc, which is composed of five 
perforated ovarial plates. 

1 ' Paleontologie Fran9ai8e,' tome vii, p. 35. 

27 



210 DISCOIDEA 

Localitij and Stratigraj)liical Position. — This species is extremely rare; on the 
authority of Professor M'Coy one only has been found iu England in the Upper Greensand 
of Cambridge ; and this type-specimen, with its anal plates, is in the Woodwardian 
Museum of Cambridge. 

Tlie Foreif/n Localities, according to M. Cotteau, are Rouen (Seine-Inferieure), Neu- 
■chatel pres Boulogne (Pas-de-Calais) ; Verronnet (Eure) ; La Chapelle Saint-Aubin, Les 
]\Ienus pres la Loupe (Sarthe) ; environs de Villedieu (Loir-et-Cher), from the Etage 
Turonien, where it is very rare. 



DiscoiDEA Favrina, Bcsor, 1842, PI. XLVIII, fig. 1 a — g. 

DiscoiDEA F.vvRiXA, Besor. Monogr. Jes Galerites, p. 62, pi. vii, figs. 12 — 16, 1842. 
— — Forbes. Mem. of Geol. Survej-, Decade I, descrip. pi. viii, 1849. 

Diaf/noms. — Test sub-pentagonal ; upper surface elevated, round, more or less inflated ; 
base flat ; mouth-opening small ; vent oblong, midway between the peristome and border ; 
inter-ambulacra wide, two prominent rows of primaiy tubercles ; ambulacra narrow ; five 
plates opposite one inter-ambulacral. 

Dimensions. — Height seven tenths of an inch ; latitude one inch. 

Description. — This Urchin was first figured by my friend Professor Desor under the 

name Discoidea rot/da; he informs us that when the plates were executed for his 

beautiful memoir on the Galeritida his knowledge of the D. rotula was limited to moulds 

of this species, or to moulds with a fragment of the test adherent, but so much effaced 

that it was impossible to study its intimate structure. As he had recognised among 

the Urchins sent to M. Agassiz by M. Alex. Brongniart from the " Glauconie" of Bouen, 

who had first figured D. rotula, a species very similar in form to the others, he thought he 

could identify it with D. rotula ; subsequently ^L Favre, of Geneva, sent from Saxonnet 

a specimen of D. rotula with its test perfectly preserved. This specimen he compared 

with those sent from Rouen, when he found that the tubercles on D. rotula from Saxonnet 

were very different from those on the specimens from Rouen, for instead of being 

scattered without apparent order on the surface of the test, they formed horizontal series 

very continuous, resembling those on D. macrojiyga. This discovery determined M. 

Desor to separate the Saxonnet specimen from those derived from the " Glauconie " of 

Rouen, and to describe it under the name Discoidea Favrina. 

The specimen I have figured from the British Musemu collection was identified by the 
late Dr. Woodward as the representative of Desor's species from the Upper Greensand ; 
the test has a subpentagonal outline, is considerably elevated with a convex dorsal surface 



FROM THE UPPER GREENSAND. 211 

(fig. 1 c) ; the base is flat ; the mouth-opening small (fig. 1 b, and the oblong vent 
occupies a space midway between the peristome and the border. 

The arabulacral areas are formed of small irregular-shaped plates, many of a triangular 
form. On each of these is a primary tubercle, so placed that on every three plates we 

observe an oblique disposition like this . : * The poriferous zones are very narrow, 

and there is one pair of pores opposite each of the arabulacral plates, of which five are packed 
within the vertical depth of one inter-ambulacral. Fig. 1 e shows the structure of one of 
these areas magnified four diameters, and the form of the individual plates is well 
delineated in this drawing. 

The inter-ambulacral areas are four times the width of the arabulacral ; the tubercles 
are arranged with much regularity, and two series in each area, situated about one third 
the distance between the zones and the median sutures, are formed of larger primary 
tubercles, which are elevated on a slight carinal ridge of the plate, and extend unin- 
terruptedly from the apical disc to the peristome ; this ridge is faintly represented 
by a vertical line in fig. 1 e ; besides the longitudinal series there are several other 
tubercles very regularly arranged, and between them the surface of the plates is covered 
with a microscopic granulation. The tubercles are larger at the base, and form hori- 
zontal rows on the plates (fig. 1 y), where several of the basal plates are drawn four dia- 
meters to show this arrangement of the tubercles with their encircling granules. The 
structure of the basal portion of the single inter-ambulacrum with the oblong vent is w^ell 
shown in fig. 1/, where the two primary series of tubercles flank the periprocte, and others 
fill up the intermediate spaces ; in this figure, likewise magnified four diameters, we observe 
that each alternate plate of the basal portion of the ambulacra supports a priraary tubercle. 

The apical disc (fig. 1 d) is formed of five irregular, pear-shaped ovarial plates, four of 
which are perforated ; the right antero-lateral is larger than the others, and supports as 
usual the madreporiform body. The five heart-shaped oculars with their microscopic 
orbits are wedged between the ovarials ; the elements of the disc are well soldered together 
and form a compact body. 

The mouth-opening is small, and occupies a slight central depression (fig. 1 b). 

Afmities and Differences. — This Urchin closely resembles D. cylindrica, a species 
which presents many interesting varieties of size and form from difi'erent localities, scarcely 
two specimens from the Grey Chalk of Folkestone, or the Lower Chalk of the South of 
England, being precisely alike. The same remark may be made of the specimens of 
B. cjjlindrica now before me from the Planer of Hanover, the Craie Chlorite of La Fauge 
(Isere), and the £tage Cenomanien of Saint- Aignan (Drome), and of other departments of 
France; such being the case I accept B. Favrina only as a provisional species 
until a series of specimens have been found which may determine more accurately 
its specific charactei's. 

Locality and Stratigrapliical Position. — The specimen I have figured belongs to the 



212 DISCOIDEA. 

British Museum, and was obtained from the Upper Greensand. Professor Desor's type 
was collected by Professor Favre from the same stage at Saxonnet. My late colleague. 
Professor Forbes, stated in his note on alUed British species of D. cylindrica .• " I think 
it not improbable that in the end we shall have to adopt the specific appellation 
Favrina for the Greensand species ; and that the Chalk specimens alluded to will prove 
varieties of cylindrica; but a comparison of the types themselves only can settle the 
matter." ' Memoirs of the Geological Survey, British Organic Remains,' Decade i ; note 
to plate viii, Biscoidea cylindrica. 



DiscoiDEA DixoNi, Forbes, 1850. PI. XLVIII, fig. 2 a—d, fig. 3 a, b. 

DiscoiDEA DixoNi, Forbes, in Dixon's Geology of Sussex, pi. xxiv, figs. 13, 14, 1850. 
— — Forbes, in Morris's Catal. of British Fossils, 2nd ed., p. 77, 1854. 

Diagnosis. — Test small, circular ; upper surface elevated, dorsum convex, sides 
inflated ; base slightly convex ; mouth-opening and vent very small ; inter-ambulacra 
wide ; two rows of primary tubercles more prominent than the others ; surface of the 
plates finely granulated ; l)asal tubercles larger ; apical disc small ; the five genital plates 
all perforated. 

Dimensions. — Height five twentieths of an inch ; latitude three tenths of an inch. 

Description. — In describing this Urchin, which he found in Mr. Frederick Dixon's 
' Cretaceous Fossils from Sussex,' my late colleague, Professor Edward Forbes, observes : 
" In form and size this species resembles Discoidea subuculus ; also in the proportional 
number of ambulacral as compared with the inter-ambulacral plates, and the granulation 
of their surfaces. It is distinguished, however, by the proportions and dimensions of 
mouth and anus as compared with the whole ventral surface. The mouth, instead of 
being (as in subucuhis) nearly equal in diameter to the distances between its sides and 
the margin of the inferior surface, is scarcely half that size, and the anus, instead of 
occupying the greater part of the space between the mouth and the margin, fills less than 
half of it."^ 

This elegant little Urchin has likewise the upper surface elevated, the sides inflated, 
and the base slightly convex, a careful comparisou of type-specimens discloses the affinities 
and differences subsisting between these congeneric forms. 

The ambulacral areas, half the width of the inter-ambulacral, have a row of small 
tubercles on the zonal side of the plates, one tubercle on every other plate in the column, 
and a second row more irregular than the former, filHng in only the wider part of the area 

' ' Dixon's Geology and Fossils of Sussex,' p. 341. 



ECHINOCONUS. 213 

■('iig. 2d); the surface of the plates is likewise covered with numerous microscopic 
granules set in horizontal rows. There are four ambulacral plates opposite each inter- 
ambulacral, and a pair of oblique pores correspond to each ambulacral plate. 

The inter-ambulacral areas have two rows of primary tubercles, nearer the zonal than 
the sutural side of the plates ; these rows extend from the disc to the peristome (fig. 2 a, b, 
• and fig. 3 a) ; each plate besides, near the ambitus, supports four smaller tubercles 
'placed less regular on the surface than those forming the vertical series. The surface of 
the plates is likewise covered with a most abundant development of microscopic granules 
arranged in horizontal rows in the direction of the long diameter of the plate. Fig. 2 d 
shows this condition of the surface in the plates of both areas magnified six times ; all the 
tubercles are perforated and crenulated. Those on the base are large as shown in fig. 3 a, 
where the test is magnified twice ; and the details of a portion of the same are very well 
exhibited in fig. 3 h, where a portion of both areas is accurately drawn eight times the 
natural size. These admirable drawings by my friend Mr. C. R. Bone render any 
detailed description unnecessary, as they are correct representations of the minute anatomy 
•of the test carefully drawn under a lens. 

The apical disc is level with the general surface, and all the five ovarial plates are 
perforated (fig. 2 c), as in D. minima. 

The base is slightly convex ; the small mouth-opeuing is quite superficial, and its 
.peristome is marked with microscopic incisions ; the vent is oblong, and occupies the 
middle of the space between the peristome and border, which is rounded and inflated, 
but never angular as in B. snbuculus. 

Affinities and Differences.— ^\\Qn compared with D. suLucuIas it is distinguished by 
•the proportions and dimensions of mouth and vent as compared with the whole ventral area, 
which are much larger in D. subiicidus than in D. Dixoni. M. Cotteau is inclined to 
unite D. Dixoni to D. minima, as the apical disc in both has each of the five genital plates 
^perforated, whereas, in other congeneric forms, only fom- of the ovarials are so. 

Locality and StratiffrapMcal Position.— The type-specimen was collected from the 
White Chalk of Sussex, and the original of our figures belongs to the British Museum. 



Gemcs — Echinoconus, Breynim, 1732. 
CoNULUS, ffZwi, 1734. EcHiNiTES, Xe«^e, 1778. Gtale rites, Zamarc/:, ISO 1 . 

Shell round, oval, or pentagonal ; enlarged a little before and slightly contracted 
behind ; upper surface more or less elevated, and having a rounded or conoidal form ; 
:summit central ; under surface flat, border rounded or angular, sometimes concave in the 
middle, rarely undulated by the depression of the ambulacra. 

Mouth-opening small, circular, decagonal, in the centre of the base; peristome 



214 ECHINOCONUS 

notched with internal auricles, and supporting a pentagonal masticating apparatus ; vent 
oval, acuminated above, opening on the border, either marginal or infra-marginal. 

Ambulacra lanceolate ; poriferous zones narrow ; pores unigeminal, except near the 
peristome, Avhere they are trigeminal. 

Inter-ambulacra wide, with numerous primary tubercles, small on the sides and 
upper surface, and larger at the base ; in both crenulated and perforated ; miliary granules 
either microscopic and homogeneous, filling up all the intermediate spaces, or larger and 
more developed, and disposed in regular cii'cles around the primary tubercles. 

The apical disc, placed at the centre of the summit, is quadrangular, solid, and 
compact, and composed of four perforate and one imperforate ovarial plates ; the right 
antero-lateral is much the largest, and is prolonged posteriorly with a portion of the 
madreporiform body into the centre of the disc ; the three other plates are much smaller, 
and terminate externally in prominent angles, in which the genital aperture is pierced. 
The five ocular plates are very small, and interposed between the angles of the ovarials. 

The genus EcMnoconus is distinguished from Discoidea by the position of the vent, 
and the absence of projecting processes from the interior of the test ; from Pygaster by its 
infra-marginal vent, absence of a dorsal aperture, and its elevated conoidal test ; from 
Holedjjjms by its elevated profile and much smaller mouth- and vent-openings ; from Fyrina 
in the quadrangular structure of the apical disc, its more pentagonal and conoidal 
form and regular decagonal peristome provided with five jaws, and by its infra-marginal 
vent. 

In Professor Desor's valuable Monograph on the Galerites twelve species are beauti- 
fully and accurately figured belonging to the genus Echinoconus, such as I have defined 
it ; after a careful study of this series, and a comparison with a collection of specimens of 
many varieties now before me, I have come to the conclusion that they all are referable 
to four types, each of which may be described as a distinct species. These are — 

1st. B. casfanea. — Has an oblong form, enlarged anteriorly and contracted posteriorly ; 
the upper surface depressed ; it belongs to the Upper Greensand, the Chalk-marl, and 
Lower Chalk. 

2nd. E. sub-rotundus. — Has a tall, round, or sub-globular test, and appears to be one 
of the many forms which were figured by Klein and described by Leske under the name 
Echinites vulgaris ; the specimens grouped together were siliceous moulds, entirely destitute 
of shell, and clearly referable to several specific forms ; one of them may represent the 
beautifid test I have figured ; but as it is impossible to determine its identity, I pi'efer 
retaining the appropriate name given to it by Mantell. This species is collected from 
the Lower Chalk of Sussex, and several of my specimens came from Lewes. 

3rd. E. conicus. — This is the true Echinoconus vere conicus ; marmo-terrestris, 
creta rejiletus ; ex cretcB fodhik Ca/itianis, oi Breynius ; two years later Klein named it 
Comdus albogalerns on account of its fancied resemblance to the white caps worn by the 
priests of Jupiter ; it has been frequently figured (see the synonyms of this species) and 



FROM THE LOWER CHALK. 215 

■described under that name; there never was any mistake about the typical form of this 
species ; although its generic and specific names have been frequently changed ; in justice 
to its original author I have restored its old name. It appertains to the Medial Chalk. 

4th. E. abhreviatus. — This species was proposed by Lamarck for a large flint mould 
figured by Leske ; but whether that form is the prototype of the Urchin to which I now 
apply the name is uncertain, for moulds seldom possess specific characters and ought 
never to have been described and figured as representatives of species ; moulds having 
been so admitted by former authors have led to interminable confusion, and E. abhre- 
viatus is one of many examples that might be adduced of this error. My learned friend, 
Professor Desor, in his valuable Monograph, has cited thirty-one references to Galerites 
abbreviata, Lamk., and given excellent figures of one of the varieties, which is the 
G. vulgaris of Goldfuss and Bronn. The first figure that can be relied upon as truly 
representing E. abhreviatus, Desor, is that given in Woodward's ' Geology of Norfolk,' pi. v, 
figs. 2 and 3, p. 47, where it is entered in his stratigraphical list of fossils as G. vulgaris, 
I have a series of type-specimens of this Urchin from the same chalk pits, and have 
ascertained the accuracy of this identification ; we next find that G. vulgaris, Woodward, 
is G. angulosa, Desor, pi. iv, figs. 5 — 7, and Caratomus liemisph(Bricus, Desor, pi. v, 
figs. 14 — 19 ; both these species were drawn and described from English specimens collected 
from the White Chalk of Norwich, and sent by the Marquis of Northampton to Professor 
Agassiz, so that there can be no mistake about the identity of the original specimens most 
beautifully and accurately figured in Desor's valuable work. 

A. — Species from the Lower Chalk. 

EcHiNocoNUS CASTANEA, Brongniart, 1822. PI. LI, fig. 2 a — g, fig. 3. 

Ntjcleolites CASTANEA, Brongniart. Geol. Environs Paris, pi. q, figs. 13, 14, 

1S22. 

— — Defrance. Diet. Sc. Nat., tome 35, p. 214, 1825. 
Galerites castanea, Agassiz. Echinod. Foss. Suisse, pi. xii, fig. 7 — 9, p. 77, 

1839. 
Catopygus CASTANEA, Agassiz. Prodrome des iScbiniJes, p. 185, 1835. 

Pykina CASTANEA, DesmouHns. Etudes Echiiiides, p. 185, 1837. 

Galerites Kothomagensis, Agassiz. Cat. Syst. Ectyp., p. ". 

— CASTANEA, Besor. Monogr. des Galerites, pi. iv, figs. 12 — IC, p. 23, 

1842. 

— — Agassiz and Besnr. Catal. rais. des Echinides, Ann. Sc. 

Nat., 3rd series, vol. vii, p. 149, 1847. 

— — Morris. Catalogue of British Fossils, p. SO, 1854. 

— — Forbes. Mem. Geol. Surv., Decade iii, pi. vii, 1850. 
EcHINOCONUS CASTANEA, d'Orbigny. Revue deZool., p. 21, 1854. 

Galerites Kothomagensis, Sismomla. Echin. Foss. de Nizza p. 51, pi. 2, figs. 8 10, 

1843. 
EcHiNocoNUS CASTANEA, Cotteau. Paleoutol. Frau^aise, t. vi, p. 503, pi. 990. 

— — Be Loriol. Ours, de la Suisse, pi. xiv, fig. 1, 1873. 



216 ECHINOCONUS 

Biapiosis. — Test oval, pentagonal, enlarged anteriorly, contracted and rounded- 
posteriorly ; upper surface elevated and convex ; sides inflated; base contracted, slightly 
convex or flat. Mouth-opening small, roundish, and central ; vent large, elliptical, 
marginal ; ambulacra narrow, prominent, corresponding to the angles of the test. 
Poriferous zones linear, pores unigeminal ; apical disc small, central, soldered to the plates^ 
of the test. 

Bimensions. — The following measurement of six specimens is given to show the- 
variability of the proportions of this species. 





A. 


B. 


c. 


D. 


E. 


F. 




G. C. 


G. C. 


G. C. 


U. G. 


C. M. 


C. M. 


ength 


2 


1 *' 


1^ 


iiV 


1 


9 
10 


readth . 


lA 


It^o 


ll^ 


1 


9 
10 


9 
10 


eight 


li^ 


1^ 


17 
20 


9 
10 


tV 


6 
10 



G. c. means Gritty Chalk ; u. g. Upper Greensand ; c. m. Chloritic Marl ; and the measurements are^ 
in inches and parts of an inch. 

Description. — The two Urchins, from the cretaceous rocks of Savoy, drawn in pi. q,. 
figs. ]4 and 17, of M. Alex. Bronguiart's 'Description Geologique des Environs de 
Paris,' and described under the names Nucleolitcs castaiiea, Al. Br., fig. 14, and 
Nucleolifes depressa, Al. Br., fig. 17, have occasioned much diversity of opinion among 
Palaeontologists in consequence of the unsatisfactory condition of the specimens them- 
selves and the inadequacy of the figures for subsequent determination. 

Having collected many specimens of this species showing its various stages of growth, 
I am enabled to state that the two forms figured by Brongniart are only different conditions 
of the same species, my larger shells agreeing with K castanea and the smaller with 
N. depressa. 

I have given the anatomy of the test with ample details of structure of the largest 
specimen I have seen from a very fine fossil in my collection (fig. 2 a— y) ; the smaller 
and commoner shell is drawn in fig. 3. 

The distinctness of the two forms has been persistently maintained by most foreign 
authors, as our table of synonyms shows ; nevertheless in this, as in other matters, 
authority must bend to facts, and dry anatomy settle the question of the unity of the 
species. 

The British specimens of Eclnnoconus castanea nearly all belong to the small variety ; 
these were collected from the Chloritic Marl near Chaldon, Dorset, and most of them 
have the test beautifully preserved. My larger specimens were obtained from the bed of 
hard gritty siliceous Chalk near Folkestone, and are equally well preserved, so that both 
varieties belong to the lower portion of the Cretaceous formation. 

All my specimens are of an ovate or sub-globular form, incKning to a pentangular or 



FROM THE UPPER GREENSAND. 217 

hexangular outline. They vary much in the degree of height and tumidity, as compared 
with their length and breadth ; the upper surface is sometimes convex and sometimes 
depressed ; the anterior half of the shell is more enlarged than the posterior, the widest 
portion being the region across the antero-lateral ambulacra (fig. 2 b, d). The obscure 
angles, when they are five, correspond to the ambulacral areas ; when there is a sixth it 
is in the centre of the sinde inter-ambulacrum. The sides are so rounded that their 
most tumid portions are central or sub-central. 

In the large specimen (fig. 2 h) the base is flat, inclining to concave, in the smaller 
specimens from the Chloritic Marl, as in fig. 3, the border is so rounded off at the sides 
that it becomes slightly convex, in the still smaller varieties it is mostly flat. 

The ambulacral areas are narrow, tapering towards the disc and peristome, and widest 
above the ambitus (fig. 2 a, b, c) ; they are formed of narrow plates four or five of which are 
opposite one inter-ambulacral ; four rows of tubercles set in a zig-zag arrangement occupy 
the area (fig. 2 e), and those at the base are much larger than those on the sides. The 
poriferous zones are linear and the very small pores arc set in triple oblique pairs, 
six or eight pair being opposite the vertical height of one inter-ambulacral plate. 

The inter-ambulacral areas, four times the width of the ambulacral, are formed of broad 
and well-developed plates (fig. 2 a, b, c) ; in the large specimen (fig. 2 c), twelve of these 
are found in each column between the disc and border, and six between the border and 
peristome ; each plate supports two rows of tubercles set in irregular horizontal lines 
above each other, four or five tubercles occupying each row. Fig. 2 e shows two 
complete and two incomplete inter-ambulacral plates, and a portion of the ambulacral 
area and poriferous zones magnified four times ; besides the primary tubercles the surface 
of the plates of both areas is covered with numerous microscopic granules. The basal 
have larger tubercles than the lateral plates. Fig. 2/ shows two of these plates from the 
middle of the base magnified four times ; the crenulations of the boss and the perforations 
at the summit are better seen in this than in the other figure. 

The apical disc is composed of five genital and five ocular plates ; four of the former 
are perforated and the single plate is imperforate (fig. 2y). The right antero-lateral 
genital plate is much the largest and supports the madreporiform body, which extends 
backwards and fills the central portion of the disc. The small cordate perforated oculars 
are wedged into the angles formed by the ovarials and complete the circle of the disc, the 
elements of which are well soldered together to form a compact structure ; and the surface 
of the plates uncovered by the spongy body is studded with close-set microscopic granules. 

The mouth-opening is small and oval (fig. 2 b), the long diameter extending obliquely 
across the base from the left to the right side ; the peristome is obscurely decagonal and 
divided into ten nearly equal-sized lobes. The base is sometimes flat, or slightly con- 
cave, as in the large specimen (fig. 2 b), or it is flattened in the centre and rounded off at 
the sides, or sometimes it is slightly convex (fig. 3) ; in either case the mouth-opening 
is nearly in the middle. 

28 



21S ECHINOCONUS 

The vent is elliptical (fig. 2 d) ; one third larger than the mouth in vertical dimensions ; 
it is placed at the lower part of the posterior border in the single ambulacrum imme- 
diately below the margin (fig. 2 d), or just within the range of the same ; it varies a little 
in the degree of its elevation in the different specimens I have compared. 

Affinities and Differences. — This species is distinguished from its congeners by its 
elongated and pentagonal form ; it is enlarged anteriorly and tapers slightly posteriorly, 
its greatest transverse diameter being across the antero-lateral ambulacra j it becomes 
a little narrower towards the posterior border, which is rounded with an elongated ridge 
rising from the upper angle of the elliptical vent. The primary tubercles of both areas are 
of the same size ; they are sunk in areal depressions and scarcely rise above the general 
surface of the plates, the whole of the intermediate structure being covered with numerous 
close-set granules ; so that the shell of Echinoconus castanea feels smooth to the touch 
when compared with that of Echinoconus conicus or E. abbreviatus. In this respect it 
resembles E. subrotundus ; the latter, however, has a smoother test, with fewer and 
smaller tubercles on the plates ; besides this character the elongated pentagonal form 
is very characteristic of E. castanea. 

Locality and Stratit/rapJdcal Position. — Echinoconus castanea is collected very rarely in 
the Upper Greensand. A few specimens have been found in this formation at Chute Farm, 
near Warminster, and one of these now lies before me. Small forms of this Urchin in 
fine preservation are very characteristic of the Chloritic Marl near Chard, a bed of Chalk 
Marl tinged green with scattered particles of silicate of iron, which lies between the Chalk 
Marl and Upper Greensand, and contains a most interesting suite of Echinidce, all of 
which likewise occur in the Upper Greensand formation. The large figured specimen 
was obtained from the Chalk Marl near Lewes, in Sussex. I have others that were 
collected from the bed of hard gritty Lower Chalk near Folkestone, a stratum which has 
yielded many interesting Urchins, as Salenia (/ranulosa, Cijphosohia simplex, and numerous 
Polyzoa. It belongs, therefore, to the lower division of the Cretaceous formation. 

Foreign Distribution. — It was collected by Mr. Alex. Brongniart in the Albien stage 
of the Chalk at the Mountain of Fis, in Savoy ; in the same stage near Nice, by M. 
Cailliand ; in France at Escragnolles (Var), by MM. Cotteau and Koichlin ; near Pres, 
Valley de Rencurel, near Grenoble (Isere), by M. Albin Gras. 



FROM THE LOWER CHxVLK. 



219 



EcHiNOcoNUs suBROTUNDUs, MmMl, 1822. PI. LII, fig. 1 a—f; PI. LIII, fig. 2 a—^f. 



fig. 3. 



CoNDLDS SUBROTUNDUS, Mantell. Geol. of Susse.x, p. 191, tab. xvii, figs. 15 — 18, 

1S22. 
Galerites subrotunda, Agassiz. Monogr. des Radiaires, jMem. Soc. des Sc. Nat. de 

Neuchatel, t. i, p. 186, 1836. 

— — Besmoulins. fitudes sur les Echinides, p. 256, 1837. 

— — Bvjardin. In Lamarck's Auimaux sans Vertebres, 2e ed., 

t. iii, p. 313, 1840. 

— — Besor. Monogr. des Galerites, p. 18, tab. ii, figs. 11 — 14, 

1842. 

— — Morris. Catalogue of British Fossils, p. 53, 1843. 

— — Agassiz and Besor. Catal. rais. des Echinides, Ann. Sc. 

Nat., 3e serie, t. vii, p. 148, 1847. 

— Leskei, Besor. Id., p. 148, 1847. 

— SUBTRUNCATA, d'Orhigny. Prod, de Pal., t. ii, p. 272, 1850. 

— SUBROTUNDUS, Forbes. In Di.xon's Geol. of Sussex, p. 340, 1850. 

— Forbes. Mem. of Geol. Survey, decade iii, p. 6, 1850. 

— — Morris. Catal. of Brit. Foss., 2nd ed., p. 80, 1854. 
d'Orbigny. Rev. et Mag. Zoologie, t. vi, p. 20, 1854. 
Cotteau. Paleontol. Francaise terrains Cretaces, t. vi, 

p. 517, pi. 997, figs. 8— 12, 1856. 
Besor. Synopsis des Echinides Fobs., p. 183, 1S5G. 
Cotteau. Echinides de la Sarthe, p. 283, pi. xlvii, fig. 4, 

1860. 



ECHINOCONUS — 



Galebites 
echinoconus 



Diagnosis. — Test subcircular, rounded anteriorly, a little contracted, and subangular 
posteriorly ; upper surface elevated, sub-conoidal and convex ; base flat, rounded at the 
border, sides a little inflated ; mouth-opening small, roundish central ; vent large, 
luarginal, elliptical ; ambulacra narrow, plates of both areas covered with small flat, 
equal-sized tubercles. 

Description. — Under the name Galerites vulgaris, Leske, it is probable that moulds of 
IE. subrotundiis have been included. Klein's tab. xiii, fig. c — k, and tab. xiv, fig. a — k, 
are cited by Lamarck as types of G. vulgaris. As these figures all represent siliceous 
moulds, a doubt may be allowed to rest on their identity with the form I have figured in 
Plates LII and LIII. Dr. Mantell also s-ave the name Conulus subrotmidus to a doubtful 
cast ; but Desor has published excellent figures of this species from an English specimen 
collected in the Isle of Wight, and contained in the IMuseum at Neufchatel. Professor 



220 ECHINOCONUS 

Agassiz made a cast of this specimen for his collection of moulds of fossil Echinoderms^ 
This form, therefore, has become classical, and I prefer to retain it, Avith jMantell's name, 
as M. Cotteau has done, in his beautiful work on the ' Fossil Echinides of the Department 
of the Sarthe.' 

Echinoconus suhrotundus is a common Urchin in the Lower Endisli Chalk. The 
subcircular outline being rounded anteriorly, and a little contracted posteriorly, some- 
times is slightly sub-pentagonal, as in the large specimen figured in PI. LIII, 
fig. '2 a, b ; the upper surface is elevated and convex, or sub-conoidal. A fine series of 
well-preserved specimens gives about equal niunbers of both forms. The base is narrow 
and flat, and much rounded off at the border; the sides are tall and convex, not much 
inflated. Mr. Bone has given admirable figures of this species ia Pis. LII and LIII,. 
with full details of the anatomy of the test. 

The ambulacral areas are narrow and lanceolate, PI. LII, fig. 1 b, c, PI. LIII, 
fig. 2 a, b, and composed of small plates, of which five are opposite one large inter- 
ambulacral plate. PI. LIII, fig. 2 e, representing a portion of the large test near th& 
ambitus magnified four times, shows the structure of the ambulacra ; two rows of tu- 
bercles occupy the area, and form thereon irregular oblique rows ; the poriferous zones are 
extremely distinct ; the pores are very small, one oblique pair corresponding to each plate. 

The inter-ambulacral areas are nearly three times the width of the ambulacral, and 
formed of wide deep plates (PI. LII, fig. d, PI. LIII, fig. 2 e). In the large specimen 
(PI. LIII, fig. 2 c, d) there are fifteen plates in each column between the border and the 
disc, and six or seven between the border and tlie periostome ; each plate supports three 
or four longitudinal series of tubercles arranged in quincuncial order, fig. 2 e, each sur- 
rounded by an ai'eola, and having its summit perforated ; the tubercles on both areas are 
very small, indistinct, and nearly homogeneous, and can only be seen Avith a lens, so that 
the shell appears quite smooth to the naked eye. The inter-tubercular surface is covered 
with microscopic granulets. 

The base is flat, PI. LII, fig. 1 a, PI. LIII, fig. 2 b, sometimes it is undulated from 
the convexity of the basal inter-ambulacra, and the tubercles are a little larger than those 
on the sides ; PI. LIII, fig. 3, represents the arrangement they assume on three basal 
plates magnified six times ; the bosses are crenulated, and the tubercles perforated. 

The mouth-opening is small and central, about one sSventli the diameter of the base ; 
and the periostome presents very feeble indications of entailles (fig. 2 b). 

The vent is larger than the oral opening, and occupies the border (Pis. LII and LIII) ; 
it has an elliptical form, placed vertically, the most acute angle being directed upwards 
(PI. LIII, fig. 2, b, d) ; the opening is on the same plane with the border of the test, and the 
single inter-ambulacrum is neither tumid or rostrated, like E. abbreviatus (Pi. LIII, fig. 1). 

The apical disc is firmly soldered to the surrounding plates, and is almost always well 
preserved ; it is small, and consists of five ovarial plates, four of which are perforated, and 
one single imperforate, the antero-lateral plate is large, and projects into the centre of 



FROM THE MEDIAL CHALK. 221 

the disc, supporting on its surface the madreporiform body. The five ocular plates are 
very small cordate bodies, wedged between the ovarials (PI. LH, fig. e, PI. LHI, 2/). 
The surface of all the discal elements is covered with microscopic granulets. 

Affinities and Differences. — This species resembles some globular varieties of E. 
vulgaris, and is often grouped with these in collections. It has a more globular form 
and is less elongated, the ambitus is more rounded, and the vent opens higher up in the 
border. It differs from E. castanea in the general outline of the test by being more 
globular, and elevated with a more convex dorsal surface. The same characters dis- 
tinguish this species from E. conicus, from which, however, it further differs in having 
smaller tubercles, and a more microscope form of granulation. It differs from E. 
abbreviatus in the general form of the test, and in having much smoother plates, from the 
smallness of its tubercles ; those in E. abbreviatus being larger, and surrounded by a 
more prominent granulation ; the vent likewise is more inferior, and the single inter- 
ambulacrum neither tumid nor rostrated as in this species. 

Locality and Stratip-aphical Position. — I collected my large specimen from the Lower 
Chalk, near Lewes, in Sussex ; it is found in the same stratum at Charing, in Kent, and 
in the Lower or Hard Chalk at Feltwell Marborough, in Norfolk, it is therefore a 
fossil characteristic of the Lower Chalk, and in this respect differs from E. conicus, E. 
globulus, and E. abbreviatus, vi\\\d\ all appertain to the Medial and Upper Chalk. The Rev. 
T. Wiltshire, E.G.S., has collected this species in the Lower Chalk, near Folkestone, from a 
stratum fifteen feet above the bed of hard gritty chalk, but never in the gritty chalk itself. 



B. — Species from the BFedial Chalk. 



EcHiNOCONUS CONICUS, Brcynius, 173.2. PI. XLIX, figs. 2, 3, 4 ; PI. L, figs. 1 — 6. 

Eciiixocoxus ver£ conicus, Breynius. ScbeJ. de Echiuis, p. 57, pi. iii, fig. 12, 

1732. 
CoKHLUs ALBOGALERCS, Klein. Natiir. dispositio Echinoderm., p. 2-4, tab. xiii, 

A, B, 1734. 
EcHixiTE CONOIDE, Bourguet. Trait. desPetrif., p. 77, pi. liii, fig. 360, 1742. 

CoNULUS ALBOGALEEXJS, Leslie. Apiid Klein, p. 1G2, tab. xiii, a, b, 1778. 

Echinus — Gmelin. Systema Naturse, p. 3181, No. 46, 1789. 

— — Bruguiere. Tab. Encjcl. Atlas, pi. clii, figs. 5, 6, 1791. 
CoxuLUs — Par/iinso7i. Organic Remains, vol. iii, pi. ii, figs. 10, 1 1, 

1811. 
Galerites — Lamarck. Animaux sans Vert., t. iii, p. 20, 1816. 

— — Befrance. Die. Sci. Nat., t. xviii, p. 86, 1820. 

— — Brongniart. Foss. envir. de Paris, p. 631, pi. 1, tig. 12, 

1822. 



222 



ECHINOCONUS 



Galerites pyramidalis, 
conulus albogaierus, 

Galerites — 



COXULUS 

Galerites — 



ECHINONEUS 



DiSCOlDEA ALBOGjVLEKA, 



Galerites pyramidalis, 

— albogalerus, 

— pyramidalis, 

albogalerus, 

pyramidalis, 

— albogalerus, 



PYRAMIDALIS, 

ANGULOSA, 

ALBOGALERUS, 



— PYRAMIDALIS, 
• — ANGULOSA, 

ALBOGALERUS, 



echinocoxus — 

pyramidalis, 

angulosus, 

Galerites albogalerus, 

echixoconus — 

— COXICUS, 

— subpyramidalis, 
Galerites albogalerus. 



Brongniart. Idem. 

Mantel! . Geol. of Sussex, p. 190, pi. xvii, figs. IG— 19, 

1822. 
Deslongchamps. Zoophytes Ecycl. Method., t. ii, p. 431, 

1824. 
Goldfuss. Petrefacta, t. i, p. 127, pi. xl, fig. 19, 182C. 
Fleming. History of British Animals, p. 481, 1828. 
Stokes. Trans. Geol. Soc. Lend., 2nd ser., vol. ii, p. 40G, 

pi. xlv, figs. 14, 15, 1829. 
Be Blainville. Zoophytes Die. So. Nat., t. Ix, p. 194, 

1830. 
Agassiz. Jlonogr. des Radiair., Mem. Soc. Neuf., t. i, 

p. 186, 1836. 
Desmotdins. Etudes sur les Echinid., p. 248, 183". 
Desmoulins. Idem. 

Agassi:. Catal. Syst. Ectyp. Foss., p. 6, 1839. 
Agassiz. Idem. 

Diijardin. In Lamarck, 2ad ed., t. iii, p. 306, 1840. . 
Dujardin. In Lamarck, idem. 

Bwmer. Norddeutschen Kreidegebirges, p. 32, 1840. 
Desor. Monogr. des Galerites, tabs, i and xiii, p. 11, 

1842. 
Desor. Idem, p. 13, tab. i, figs. 1 — 3. 
Desor. Idem, p. 22, tab. iv, figs. i> — 7. 
Morris. Catalogue of British Fossils, p. 53, 1843. 
Agassis and Desor. Catal. rais. des Echinides, Ann. So. 

Nat., 3rd ser., t. vii, p. 148, 1847. 
Agassiz and Desor. Idem. 
Agassiz and Desor. Idem. 
d'Orhlgny. Pal. Stratigraph., t. ii, p. 272, 1850. 
d'Orhigiiy. Idem. 

Forbes. In Dixon's Geol. of Sussex, p. 340, 1850. 
Sorignet. Oursin Foss. de I'Eure, p. 40, 1850. 
Forbes. Mem. Geol. Survey, decade iii, pl. viii, 1850. 
Bronn. Letbeea Geognost. Kreidegebirges, p. 191, 

pl. sxix, fig. 18, a, h, 1857. 
Quenstedt. Handbuch der Petrefalc, p. 583, 1852. 
d'Orbigny. Revue et Mag. de Zoologie, p. 20, 1854. 
f/' Orbigny. Idem. 
d' Orbigny. Idem . 
Forbes. In Morris's Catalogue of Brit. Foss., 2ud ed., 

p. SO, 1854. 
Cotteau. Ech. Foss. Pyrenees, Bulletin Soc. Geol. de 

France, 2e ser., t. xiii, p. 258, 1856. 
d'Orbigny. Palseontol. Francaise ter. Cretaces, t. vi, 

p. 513, pl. 996, 1856. 
d^ Orbigny. Idem, pl. 1000, p. 530. 
Pictet. Traito de Paleont., pl. scv, fig. 12, 1S57. 



PROM THE MEDIAL CHALK. 223 

Galerites albogaleeus, Desor. Synopsis des Echinides Foss., pi. xxv, 1857. 
EcHiNOCONUs coxicus, CotteuH. Echinides du Depart, de la Sarthe, pi. 47, 

figs. 1—3, i860. 

Diagnosis. — Test much elevated, conoiclal, larger anteriorly than posteriorly ; slightly 
angular and rounded at the border ; base flat ; single inter-ambulacrum tumid and re- 
curved ; vent large, oval, infra-marginal ; mouth-opening central, periostoma decagonal, 
armed with five pairs of dentiferous jaws ; ambulacra straight, narrow, doubly lanceolate ; 
pores small, unigeminal, in oblique pairs, which become trigeminal near the periostome ; 
interambulacra wide, angular ; tul)ercles on both areas small, homogeneous ; granules 
abundant, unequal, sometimes elongated and prominent ; apical disc small, quadrangular, 
very solid. 

Dimensions. — Height, one inch and five tenths ; latitude, one inch and four tenths. 

Description. — I recognise three well-marked vai'ieties of form in this Urchin, which 
have been described as distinct species by different systematic authors : these are, 
according to my reading of the matter, as follows : — 

PoRMA a. Cotiica. — This may be regarded as the normal form, and as such it is figured 

as the type of the species. 
EoRMA /3. Pijramidalis. — Desor, ' Monographic des Galerites,' PI. I," figs. 1 — 3 ; 

d'Orbigny, Paleontologie PI. 1000, figs. 5—7. A small 

test, with pyramidal elongation of the vertex. 
PoEMA y. An(/ulosa. — Desor, ' Monographic des Galerites,' PI. 4, figs. 5 — 7, a 

depressed, elongated, and angular variety of Conica. 

Description. — This is the most typical of all the Echinoconi, and has been well 
figured and described by most classical authors who have described the different forms 
of this genus. It is the true Echinoconus vere conicus of Breynius, 1732 ; two years later 
it was figured and described as Conulus alho-gcderus by Klein, on account of its supposed 
resemblance to the white caps worn by the priests of Jupiter. Lang figured it in 1708 
as Echiiwmetritis in his ' Historia Lapidum figuratorum Helvetije,' and Bourget in his 
' Traitc de Petrifactions,' as the EcUnite conoide, whilst Lamarck made it the type of his 
new genus Galerites, reserving for it the specific name idbo-gcderus, given by Klein, by 
which it has been known to the present time. 

The general form of this Urchin is conical, varying in different specimens from a tall 
pyramid, with very steep sides, to a short one with infiated walls ; the base is flattened, 
its circumference slightly pentangular, the greatest width corresponding to the region of 
the antero-Iateral ambulacra ; the basal angle is more or less rounded, and the single 
inter-ambulacnim tumid and recurved. 

The ambulacral areas are doubly lanceolate, and built up of minute plates, which in 
the upper part of the area are often cuneiform in shape, irregular in size, and some- 



224 ECHINOCONUS 

times separated from each other by small accessory pieces ; near the ambitus they 
have a more regular shape, as seen in PI. L, fig. 1 d. All the plates are narrow, four or 
five corresponding in depth to one inter-ambulacral plate. In the large specimen drawn 
in PI. XLIX, fig. 3, there are fifteen plates in each dorsal inter-ambulacral column 
between the angle of the disc, so that in this specimen, in the same space, there are 
seventy-five plates in each half of an ambulacral area ; there are four rows of primary 
tubercles in the widest part of the area, which have a zig-zag arrangement, the two 
inner rows, which are the most irregular, disappear near to the middle of the base, and about 
the upper fourth of the dorsal surface. The poriferous zones are very narrow, the pores uni- 
geminal and oblique, six pairs being often opposite one large plate ; near the mouth they 
form sets of triple oblique pairs, as in the example (fig. 5), magnified four times; from 
several specimens before me in different stages of weathering, I have ascertained that a 
small cuneiform plate is apportioned to each pair of holes ; this plate appears to have been 
formed of two halves, so as to embrace the tubular feet ; the plates, therefore, of the 
poriferous zones are not perforated for the soft parts, but have, in fact, grown around 
them in the process of development. 

The inter-ambulacral areas are three times the width of the ambulacral at the 
ambitus (PI. L, fig. 1 d) ; they are formed of large plates, each supporting from 10 to 14 
primary tubercles, arranged in irregular horizontal rows, which sometimes assume an 
hour-glass-shape-like disposition ; each of these tubercles is spiniferous (fig. 1/), and 
is encircled by a smooth depressed areola ; the boss is large, mammillated, and 
crenulated at the summit, and the small round head is perforated ; those at the base are 
larger, and form more regular horizontal rows ; when examined with an inch object-glass 
they present the appearance shown in fig. 1/. The inter-tubercular surface is covered 
with rows of microscopic granules (fig. 1 d, e,/); the tubercles on the upper surface all 
supported short spines, which are sometimes seen i/i sit//, those at the base are large, 
about one fifth of an inch in length ; they are slender, tapering, smooth, and covered with 
fine longitudinal lines, which are delicately serrated near the summit, the stem is enlarged 
at the base, where it is encircled by a crenulated collar (fig. 3). Dr. Bowerbank made a 
microscopic examination of the spines of Ecl/inoconi in his collection, and found that the 
dorsal spines of I^. conic//s differed from those of E. siibrot//nd//s in being thickened at 
the base, and set on tubercles as it were sessile, instead of being shortly pedunculated, as 
they are in the latter species. 

The minute moniliform spines of E. comcus, according to Dr. Bowerbank, arc 
Yja of an inch in length, and of equal diameter (fig. 4). Three were accurately 
measured, and all were as nearly as possible of the same size and proportions ; they were 
all perfectly smooth. 

The mouth-opening is small and central (PI. L, fig. 1 d) ; the periostome is decagonal 
(fig. 5), and armed with a dental lantern : this fact was first discovered by INIr. Charles 
Stokes, F.G.S., and described by him in the 'Geological Transactions;' since that time 



THE 



PALJONTOGRAPHICAL SOCIETY. 



INSTITUTED MDCCCXLVII. 



VOLTJME FOE 1875. 



LONDON 

MDCOCLXXT. 




MONOGRAPH 



on THE 



BRITISH FOSSIL 



ECHINODERMATA 



FKOM 



THE CRETACEOUS FORMATIONS. 



BY 



THOMAS WRIGHT, M.D., F.R.S. Edin., F.G.S., 

CORRESPONDING MEMBER OF THE KOTAi SOCIETY OF SCIENCES OF LIEGE, THE SOCIETY OF NATURAL SCIENCES OF 

NEUFCHATEL; PRESIDENT OF THE GEOLOGICAL SECTION OF THE BRITISH ASSOCIATION, 1875 ; VICE-PRESIDENT 

OF THE COTIESWOLD NATURALISTS' FIELD CLUB ; CONSULTING SURGEON TO THE CHELTENHAM 

HOSPITAL; AND MEDICAL OFFICER OF HEALTH FOR THE URBAN SANITARY DISTRICTS 

OF CHELTENHAM, CHARLTON-KINGS, AND LECKHAMPTON. 



VOLUME FIRST. 

PART SEVENTH. 

ON THE ECHINOCONID^, ECHINONID^, ECHINOBRISSID^. 
ECHINOLAMPID^, AND SPATANGID.^. 

Pases 225—264 ; Plates LIII— LXII. 



LONDON: 

PRINTED FOR THE PALJIONTOGRAPHICAL SOCIETY. 

1875. 



PKINTBD BY 
J. E AULARD, BAKTHOLOMEW CLOSE. 



FROM THE MEDIAL CHALK. 225 

other specimens exhibiting the jaws have been discovered. The teeth are small, smooth, 
white, lanceolate, triangular, each consisting of a concave lamina, terminating below in 
the dental point, and strengthened by a prominent ridge behind (fig. 6). 

The base is flat, and both areas are covered with much larger tubercles than those 
developed on the dorsal surface ; they are arranged in irregular concentric rows around the 
peristome ; the single inter-ambulacrum is elongated posteriorly, and more tumid towards 
the border, which is sometimes rostrated and recurved (PI. XLIX, fig. 2 and fig. 4, and 
PI. L, fig. 1 and fig. 2). In this portion the vent opens ; this aperture is one third 
larger than the mouth, and broadly elliptical in a longitudinal direction ; its margins are 
thick and elevated, and appear to have supported an anal membrane. The vent is 
marginal in a majority of specimens, and is rarely seen above the border ; most frequently 
it cuts that angle obliquely (PI. L, figs. 1 and 2). 

The apical disc (PL L, fig. 1 e) is quadrangular, and formed of four perforate 
and one small imperforate ovarial plates ; the right antero- lateral is the largest, and 
extends into the centre of the disc, its surface supports the madreporiform body ; the five 
ocular plates are small cordate elements, closely wedged in the angle between the ovarials. 

Jffinities and Differences. — This typical species difiers from its congeners in its form, 
which is always conical or pyramidal ; the base is flat and sub-pentangular, and the single 
inter-ambulacrum is posteally produced, being somewhat tumid and recurved. These 
characters readily distinguish it from E. castanea. The straight, slightly inclined sides, 
the acute ambital angle, and flat base, form a good diagnosis between it and E. subrotimdus, 
which lias convex sides, a rounded ambital border, narrow base, and small inter- 
ambulacrum ; the conical form, small tubercles, and large vent distinguish it from 
E. abbreviatiis. 

LocaUty and Sir atigraphical Position. — This species is found in abundance in the 
white Medial Clialk of the English Cretaceous districts. It is very Common in the south ; 
fine specimens are obtained at Gravesend and other localities in Kent, and at SwafF- 
ham, in Norfolk. Specimens showing the dentiferous jaws are in the collections of Mr. 
Stokes, Dr. Bowerbank, and my kind friend the Rev. T. Wiltshire, F.G.S. ; to whom I 
am indebted for the figured specimen. 

Foreign Localities. — In France, according to M. Cotteau, it is found in I'fitage 
Senonien, at Meudon, near Paris, near Sens, Villeneuve-le-Roi, and Charny, Yonne; 
Beauvais and Roquemont, Oise; Chartres, Eure-et-Loire ; Vernonnet and Pinterville, 
Eure ; Bains-de-Rennes, Aude ; the environs of Aix-la-Chapelle, and in the Island of 
Ruegen. 



29 



.• 226 



ECHINOCONUS 



EcHiNocoNus ABBREviATUs, Desor. PI. LII, fig. 2 a — i ; PI. LIII, fig. 1. 



— XODUS, 

— BULLA, 
ECHIXITES VULGAKIS, 



Galerites — 

echinites 

Galerites truxcatus, 
— vulgaris, 



CoxuLus GLOBULUS, Klein. Nat. dispositio Echinodermatum, p. 25, tab. xiii, c, 

D, E, r, var. a, Wagricus ; tab. xiv, c, d, e, f, var. /3, 
Gedanensis, 1734. 

Klein. Idem., tab. xiv, g, h, Gottlandicus, 1734. 

Klein. Idem., tab. xiv, i, k, Gedanensis, 1734. 

Leske (pars), Klein. Echin., tab. xiii, c, d, e, f ; tab. xiv, 
C, D, E, F, 1778. 

Gmelin. Syst. Naturae, p. 3182, 1789. 

Bruguiere. Encycl. Method., tab. 153, figs. 6, 7, 1791. 

Lamarck (pars). Syst., p. 347, 1801. 

Lamarck. Animaux sans Verte'bres, t. iii, p. 20, 1816. 

Schlotheim. Die Petrefakten, p. 320. 

Befrance. Die. Sc. Nat. Galerites, t. viii, p. 87. 

Beslongchamps. Encycl. Method., p. 431, 1824. 

— — Goldfuss. Petrefacta Germania;, tab. xl, fig. 20, 1829. 
_ _ Woodward. Geology of Norfolk, pi. v, fig. 2, 3,1833. 

— — Blainville. Manuel d'Actinologie, p. 222, 1834. 

— PYRAMiDALis, Besmouliyis (pars). Etudes sur les Echinides, p. 248, 1837. 

— ABBREViATA, Besor. Monographie des Galerites, tab. iii, figs. 9 — 17, p. 20, 

(lion Lamarck), 1816. 

— — Agassiz and Besor. Catal. raison., p. 90 (modeles s. 65, 

s. 70). 

— VULGARIS, d'Orbignij. Prod., t. ii, p. 272, 1847. 

— ABBREVIATUS, Forbes (pars). Mem. Geol. Soc. Survey, decade iii, pi. viii, 

fig. 5, 1850. 

— — Bronn. Lethea Geognost. Kreid., p. 192, pi. xix, fig. 17, 

1854. 

— — Besor. Synopsis des Echinides Foss., p. 184, 1858. 
_ _ Morris. Catal. of British Fossils, 2 ed., p. 80, 1854. 

— — d'Orbigny. Revue de Zoologie, p. 20, 1S54. 
EcHiNocoNCS GLOBULUS, d'Orbigny. Pale'ontol. Franfaise, t. vi, tab. 999, p. 522, 

1855. 



Diagnosis — Test thick, elevated, conoidal or globular, margin almost circular, not 
angular ; wider near the anterior third ; base flat, rounded at the circumference ; single 
inter-arabulacrirai narrow, tumid, and recurved at the border ; vent prominent, infra- 
marginal; primary tubercles surrounded by deeply concave areolas ; mihary granules 
large and thickly set on the inter-tubercular spaces. 

Dimensions. — Height, one inch and one tenth ; length, one inch and four tenths ; 
latitude, one inch and three tenths. 

Descrij)tion. — The attempt to make out the history of this Urchin has proved a per- 
plexing and unsatisfactory task, inasmuch as the type-specimens figured by Klein were 



FROM THE UPPER CHALK. 227 

siliceous moulds without any portion of test attached thereto, and of these he made three 
species, Conulus globulus, C. nodus, and C. Bulla. His learned commentator, Leske, in 
his 'Additaraenta ad Kleinii Dispositionem Echinodermatura,' p. 165, groups them all 
into one species, which he described under the name EcJdnifes vulgaris, and remarks, 
" Interim hae differentiae si hasc corpora petrefacta, quae plerum.que nuclei tantum 
Ecldnitaruni sunt, attente contemplor, mihi magis videntur a mutatione, cum in petram 
converterentur Echini natarales, pendere, quam veram diversitatem specierum indicare. 
Itaqne etiam Nodum et Bullam Klenii, § 53, 54, ad varietates refero. Prout enim testa 
vel plus vel minus comprimeretur, eo vel obtusa, vel conica magis nascebatur figura. In 
nndtis speciminibus vertice obtnso, hie vi externa quasi impressus videtur." Lamarck, 
in his ' Systeme,' 1801, and in ' Animaux sans Vertebres,' 1816, followed Leske, and 
cites the Tabs. XIII and XIV of Klein's work as types of E. vulgaris. 

Leske, in his ' Additaraenta,' p. 166, describes another large mould, which he regards 
as a variety of Echinites vulgaris, and figures the same. In Tab. XL, figs. 2 and 3, of 
this specimen he observes, " Singularis et notatu digna varietas, tarn propter brunum 
colorera ; quam propter insignem magnitudineni est ea, Tub. XL, Van Phelsum banc 
iconem interrogando cum Klenii Tab. XIII, g, h, comparat. Singulares etiam rugae et 
lineas eminentes in areis conspiciuntur. Ambulacra singula biporosa fuisse videntur ; 
OS parvum ; anus oblongus ; ambitus testae est circularis.'' 

Lamarck, in his ' Aniniaux sans Vertebres,' tom. iii, p. 20, describes this mould as a 
new species under the name Galerites abbreviatus, and cites Leske's figure as its type, but 
we are left in ignorance of its true specific characters, as the test is entirely wanting. 

Schlotheim, Deslongcharaps, Goldfuss, d'Blaiuville, Desmoulins, and Milne-Edwards, 
in their several works, have followed Lamarck. 

Professor Desor, in his ' Monographic des Galerites,' first gave capital figures in 
Tab. Ill, fig. 9 — 17, and a concise description of a large Urchin with the test entire, 
and interior moulds of the same from the collection of M. de Luc. The specimens were 
collected from the detritic sands of Stada, in North Germany ; he considers these 
moulds to be the same species which Klein figured as Conulus globulus, C. nodus, and 
C. nodosa in his ' Dispositio Echinodermatum,' Tab. XIII, fig. d — h. The specimen 
with the shell was a unicum and has been valuable as helping us to a knowledge of the 
moulds which have occasioned so much confusion in our synonymy. 

Mr. S. Woodward, Sen., in his ' Memoir of the Geology of Norfolk, has figured two 
varieties of this Urchin as Galerites vulgaris, a, /3. The specimens Mr. Bone has drawn 
for this work were obtained from the same chalk pits as those from whence Mr. Woodward's 
fossils were collected, and these Norwich specimens agree so well with Desor's figure that 
there is no doubt about their identity with M. de Luc's Urchin. 

M. d'Orbigny, in his ' Palseontologie ErangaisCi' described and figured tins species 
under the name Echinoconus globulus, Klein, which, I admit, would have been correct in 
accordance with the principle of priority which has guided our nomenclature of species 



228 ECHINOCONUS 

had only one species been so named, but as Klein described three species out of what 
now appears to be mere varieties of one form in my judgment it is wiser, for the sake of 
clearnesss and precision, to avoid the revival of either of his names, as it is uncertain to 
which variety the name glohulm should be strictly applied. 

In order to define accurately this species, I have determined to adopt Professor 
Desor's figures and description as the type retaining the specific name abbreviata without 
reference to the mould to which it was first applied. 

The test is round, not angular at the border, moderately elevated; convex or 
subconoidal, a little wider anteriorly, its greatest latitude being across the antero-lateral 
ambulacra, the sides are unequally inflated, the posterior half being more protuberant 
than the anterior half, owing to the apical disc being excentral and situated a little forwards 
(PI. LII, fig. 2 c, PI. LIII, fig. 1) ; the base is flat, the mouth-opening small, round, and 
prominent ; the vent larger and opening into a recurved prominence formed by the single 
inter-ambulacrum (PI. LII, fig. 2 b, d). 

The ambulacral areas are narrow (PI. LII, fig. 2 e) and built up of a column of 
small plates, of which four correspond in height to one inter-ambulacral, the outer border 
of each pair of microscopic pedal plates are united, and in each of these a pair of pores 
are set obliquely. The anatomy of the pedal plates forming the poriferous zones is more 
satisfactorily exposed in the specimen now under examination than I have hitherto seen 
them, and clearly shows that the poriferous zones are a portion of the test distinct from the 
plates forming the inter-ambulacra and ambulacra between which they are interposed, each 
pair of holes being formed, for the passage of the tubular feet, by the growth of a pair 
of plates around the exertile pedal suckers. 

The inter-ambidacral areas are three times the width of the ambulacral ; on each 
plate are three horizontal rows of tubercles, four or five in each row (fig. 2 e), each 
is surrounded by a sunken areola, encircled by granules ; the boss is crenulated, and 
the summit of the tubercle perforated (fig. 2, (/, h). The entire surface of the 
plates is covered with granules nuich larger and more numerous than in any other 
Echinoconus. 

The base is flat or slightly concave, and the border rounded ; the single inter- 
ambulacrum convex, prominent, and recurved at the margin, where the circular vent 
opens (fig. 2 b, d); the mouth-opening is small and central, the peristome feebly 
diagonal with an elevated border at the circumference. 

The apical disc is small, and its plates so intimately soldered together that few 
specimens show the sutures (fig. 2 i) ; the disc is excentral and inclined forwards, as the 
slope from the disc to the anterior border is shorter than the slope from disc to the 
posterior border ; this is owing to the great development of the single inter-ambulacrum 
and the prominence of the basal portion of that area (see PI. LII, fig. 2c; and PI. LII, 
fig. 1). The two pairs of ovarial plates are small, their holes very large (fig. 2 i) ; and the 



FROM THE UPPER CHALK. 229 

small single plate is imperforate ; the spongy portion of the madreporiform body is small, 
and the surface of the other plates closely covered with granules. 

One remarkable feature in the structure of this test consists in the size, number, and 
prominence of the miliary granules, which cover the inter-tubercular spaces and form on 
the sides and upper surface of well-preserved specimens a thin incrustation which coats the 
plates and makes the tubercles on the sides appear as punctured depressions rather than 
elevations of the test. PI. LII, fig. 2 e, is a drawing of a portion of both areas with 
the zones magnified four diameters, taken from the side of the test ; the inter-ambulacral 
plates support three rows of tubercles, four or five in each, which are situated in a 
depression surrounded by an areola, and have some of their bosses crenulated and 
summits perforated (fig. 2 g, h). The ambulacra have four rows of similar tubercles and 
a like abundance of close-set granules on the surface of their plates. The tubercles on 
the basal plates are more numerous, the areolas wider, and the granules in a great 
measure absent from this region of the test (fig. 2/) where these large basal plates are 
situated, they are drawn, magnified four diameters. 

The mouth-opening is very small (fig. 2 b), about one third less than the vent ; the 
peristome is nearly circular, thickened and prominent like the vent, the microscopic 
plates of the inter-ambulacra being narrow and piled on each other produce the rounding 
and thickening of the peristome ; the pores in the zones are unigeminal around the 
opening. One remarkable specimen in my collection enables me to make these detailed 
observations on the minute anatomy of the test of E. ahbreviatus. 

Affinities and Differences. — This species resembles E. subrotundm in the elevation of 
the upper surface and inflation of the lateral parts. A comparison, however, of the 
profiles of both species, as given in PL LH, fig. 1 c, and fig. 2 c, and PI. LHI, fig. 1 
and fig. 2 c, will show at a glance several distinguishing characters, the excentricity 
forwards of the apical disc, the shortness of the anterior slope, as compared with the 
greater length of the posterior, and the prominence and recurvation of the single inter- 
ambulacrum. In E. subrolundus the tubercles are larger and more numerous and the 
miliary granides smaller and fewer, whilst the reverse forms one of the specific characters 
of E. ahbreviatus ; the tubercles are small and sparse, and appear sunk in the test by 
the great development of the miliary granulation which forms a thin coating on the 
lateral and upper portions of the plates. In PI. LII both species are admirably drawn, 
and the minute anatomy of the tests displayed, so that a careful examination of the 
figures, will place the affinities and differences between these confluent forms more clearly 
before the eye of the student, than the most elaborate description could convey to the 
mind. 

Locality and Stratigraphical Position. — All the examples of this species that I have 
examined were collected from the Upper Chalk at Harford Bridge, Trowse, and Trim- 
mingham, Norfolk, where it is known as a leading fossil of the Norwich Chalk. 



230 ECHINOCONUS 



ECHINOCONUS GLOBULUS, BeSOT. PI. XLIX, fig. 1 a—(). 

Galeeites globulus, Besor. Monographie des Galerites, tab. iv, figs. 1 — 4, p. 18, 

1842. 
— — Forbes. In Morris, Catalogue of Brit. Foss., 2iid ed., p. 80, 

1854. 

Diagnosis. — Test small, nearly globular; base narrow, border rounded; vent 
elliptical and supra-marginal ; inter-ambulacral plates sparsely covered with primary 
tubercles. 

Dimensions. — Height, six tenths of an inch ; length, eight tenths ; latitude, seven tenths. 

Description. — The small test figured in our PI. XLIX was always considered to be 
a distinct species by the late Dr. Woodward ; it is identical with the form first described 
and figured by Professor Desor, in his ' Monograph on the Galerites ; ' the specimen, in 
fact, which served as the type of Desor's figure belonged to the collection of M. de Luc, 
who obtained it from the English White Chalk ; at first sight it appears to be a young 
specimen of E. subrotundus ; a closer examination, however, shows it differs in essential 
points from that form. The test is slightly elongated, and is nearly globular in conse- 
quence of the narrowness of the base, and the rounding of the border ; the posterior 
carina is not prominent, the vent is elliptical and quite supra-marginal, but in conse- 
quence of the rounding of the border this aperture is visible both from the base and 
upper surface. The ambulacral areas are built of very narrow plates and have four rows 
of tubercles arranged obliquely on the area, one tubercle from the inner row alter- 
nating with a tubercle on the outer row; the poriferous zones are very narrow, the 
])ores unigeminal and oblique, six pairs being opposite one large plate (fig. 1 e). 

The inter-ambulacral areas are twice the width of the ambulacral ; each of the plates 
supports five or six tubercles arranged in quincuncial order, and the inter-tubercular 
surface is covered with microscopic miliary granules, of which a capital sketch is given in 
fig. \ e ; at the border and base the granules I'orni regular circles around the tubercles, 
as seen in fig. 1 y. Both these drawings are magnified six diameters. 

The apical disc is large and well developed in this small Urchin (fig. 1 /) ; the right 
antero-lateral ovarial is the largest plate in the disc and extends into the centre ; it is 
covered with the spongy body, and the other three ovarials forming the two pairs 
are small and of the same size ; they are perforated near their apices, and the 
small posterior single ovarial is imperforate; the five ocular plates are all well 
perforated. 

The mouth-opening is small and central, and the peristome less in diameter than 
the supra-marginal eUiptical vent. 

Affinities and Differences. — The globular shape of this Urchin resembles some forms 



FROM THE UPPER CHALK. 231 

of E. subrotundas, of which it may be only a variety ; it has, however, fewer tubercles on 
the inter-ambulacral plates, and the vent is much higher up on the test than in that 
species. Its globose form presents a remarkable contrast to the conical E. conicus, the 
elongated E. castanea, and the recurved posterior base of E. ahbreviatus. 

Locality and Stratip-apldcal Fosiiion.— This very rare species is found in the Upper 
White Chalk with flints at Gravesend and in Kent. The test I have figured is contained 
in the British Museum. 



Gems — HoLECTYPUs, Desor, 1S47. 

DiscoiDES (pars), Klein, 1734. 
EciiiNiTES (pars), Leske, 1778. 
Galerites (pars), iamarcA, 1816. 
DiscoiDEA (pars), Gray, 1835. 

The Genus Holectypus was established by M. Desor for the reception of those 
Discoidese which are deprived of ribs or projecting processes on the inner wall of the test. 
The species referred to this group constitute one of the oldest types of the Echinoconidse, 
and are met with chiefly in the Oolitic rocks. They form, according to the views of the 
late Professor Forbes, " a section or sub-genus of the Galerites, more valuable on 
account of their palajontological merits, and limited distribution in time, being in the 
main characteristic of the Oolitic period, than for the zoological importance of the 
character of their organization, which are rather transitional than distinctive." 

The test is thin, circular, or sub-circular, more or less hemispherical, conical, 
or sub-conical, always tumid at the sides, and flat or concave at the base. 

The ambulacral areas are narrow, straight, and lanceolate, with six or eight rows of 
small tubercles, of which the marginal series only extend from the base to the apex. 

The poriferous zones are narrow, and the pores are unigeminal throughout. 

The inter-ambulacral areas are three times the width of the ambulacral ; the laro-f^ 
pentagonal plates support numerous, small, perforated tubercles, which are very regularly 
arranged in vertical and concentric rows. They are raised on bosses with crenulated 
summits and surrounded by ring-hke areolas ; numerous minute granules are scattered 
over the surface of the plates and form circles around the tubercles. 

The mouth-opening is circular and situated in the centre of the base ; the peristome 
is divided by obtuse notches into ten equal lobes. The organs of mastication consisted 
of five jaws, which are preserved in situ in one specimen I collected from the Forest 
Marble of Wilts. 



233 HOLECTYPUS 

The anal opening is large, inferior, infra-marginal, rarely marginal, sometimes 
occupying the entire space between the mouth and the border. 

The apical disc is nearly central and vertical, composed of five ovarial and five 
ocular plates ; the right antero-lateral ovarial is much the largest and extends into the 
centre of the disc ; it supports a prominent, convex, madreporiform body. In all the 
Oolitic species the anterior and posterior pairs of ovarials are perforated, and the single 
plate imperforate; whilst in all the Cretaceous species the five ovarial plates are all 
perforate, and the five ocular plates are small, triangular bodies, with marginal perfora- 
tions (fig. 1 i). 

The internal moulds of Hohdypus want those depressions occasioned by ribs 
projecting from the inner walls of the test which so well characterise the genus Discoidea. 

The spines are short, with a smooth head and milled ring, and they have the surface 
sculptured with fine longitudinal lines. 

Iloledypus is distinguished from Echinocoiim by having a larger mouth and vent, 
a concave base, and a less elevated dorsal surface; and from Discoidea in having 
tumid sides, a larger mouth and vent, and the absence of ribs from the internal walls 
of the test. 

The small crenulated tubercles and basal vent, with the absence of any aperture 
in the upper surface of the inter-ambulacrum, distinguishes Iloledypus from P yg aster ; 
and the want of a longitudinal valley in the inter-ambulacrum separates Iloledypus from 
Hyboclypus and Galeropygus. 

The Genus Iloledypus is most abundant in the Oolitic rocks; the Cretaceous 
rocks of France contain seven species : one is special to the Neocomian, one to the 
Aptien, three to the Cenomanian,' and two to the Turonian stages. I now add a new 
species from the Chloritic Marl of England, and the first of this genus from the chalk 
found in the British Islands. 

The Genus Holedypus forms two natural groups, both organically and stratigraphically 
distinct from each other. The apical disc in one group has only four of the ovarial 
plates perforate ; in the second group all the five ovarials are so. The species with the 
four perforate ovarials are all Jurassic, and those with the five perforate ovarials are 
Cretaceous. 



FROM THE CHLORITIC MARL. 233 



HoLECTYPUS BiSTRiATUS, Wright, sp. IIOV. PI. LXV, fig. 3 a, h, c. 

Diapiosis. — Test sub-circular, sub-conoidal, depressed on the upper surface, and 
flattened at the base ; ambulacra lanceolate, with four irregular rows of small tubercles ; 
poriferous zones straight, narrow, with a smooth nude band extending from the disc to the 
border on the inter-ambulacral side of each zone. Inter-ambulacra wide, plates narrow, 
with horizontal rows of small tubercles on each, apical disc small. 

Dimemions. — Height eight tenths of an inch ; breadth one inch and eight tenths of 
an inch. 

Description. — This rare Urchin was collected many years ago from the Chlontic 
Marl, near Chard, by Mr. Weist, and kindly communicated for this work. It was 
long considered to be a depressed variety of Discoidea cylindrica. In developing 
the specimen, however, I displaced a portion of the test, which disclosed the 
inner surface and the mould, and it then became evident that the Urchin was not a 
Discoidea, but a true llolectypus, as it had none of the internal ribs at the ambitus which 
distinguish Discoidea; it is the first Holectypus\}i\'&X,\\^% been recorded from the Cretaceous 
rocks of England. 

The test is sub-circular, thin at the ambitus and depressed on the upper surface 
(fig. 3 U) ; the ambulacral areas are lanceolate, with four or six rows of small tubercles 
disposed in a zig-zag manner on alternate plates of the area which are very narrow, five 
of them in vertical height being equal to one inter-ambulacral plate. The poriferous 
zones are narrow, the pores small, and unigeminal, one pair of pores corresponding to 
one ambulacral plate (fig. 8 c) magnified twice. 

The inter-ambulacral areas at the ambitus are nearly three times the width of the 
ambulacra ; the columns are built of narrow plates, each supporting a horizontal row of 
small tubercles, seven to eight in a row near the ambitus and fewer up the sides, each 
tubercle is surrounded by a narrow areola, the boss of which is crenulated and the 
summit perforated. The only specimen I have seen is the one under examination; 
unfortunately, the surface of the test is so much rubbed that its minute structure can 
only be made out by selecting those parts of the plates which are best preserved for 
careful study with the glass. The tubercles are very small and numerous, and the 
horizontal I'ows they form fill up the greater portion of the surface of the plates, so that 
the number of miliary granules is inconsiderable. On each side of the inter-ambulacra, 
separating the tubercular surface from the poriferous zones, two smooth nude bands 
extend from the ambitus to the disc. These naked calcareous ribbons are very Avell 
seen on one of the areas, and this bistriated structure forms a specific character of some 
value and from which the specific name is derived. 

30 



234 ECHINONIDtE 

The apical disc is small, and the five ovarial plates are all perforated ; the spongy 
body is unich rubbed and the ocular plates so blended with the other elements that 
their individual character cannot be seen. 

The base is covered with the matrix, which adheres so firmly to the test that it is 
impossible to effect its separation from the surface without at the same time removing 
the shell. The anatomy of this region is, unfortunately, at present unknown. 

Affinities and Differences. — This species very much resembles Holecti/jms Cenomanensis, 
Gueranger both in the general outline of the test, the smallness of its tubercles, and in the 
manner they are disposed on the plates. It is found likewise in nearly the same horizon 
of the Cretaceous rocks. The only difference I can detect is the presence of the nude 
ribbon-like bands on the outer side of the poriferous zones, no indication of which is 
given in M. Cotteau's beautiful and carefully drawn figures. 

Locality and Stratigraplncal Position. — Collected from the Chloritic Marl near 
Chard, with Catoj)ygus cohimbarius, Pyrina DesmouUnsii, Cottaldia Benettits, and other 
Upper Greensand forms. 



Family 7. — Collyritid^, d'Orhigny, 1853 (not yet found in British 

Cretaceous strata). 



Family 8. — EcHiNONiDiE, Wright, 1856. 

Test thin, oval ; poriferous zones narrow, meeting at the apical disc ; pores unigeminal ; 
tubercles of both areas nearly equal in size, but neither perforated nor crenulated ; spines 
stout, subulate. Mouth-opening nearly central, irregularly pentagonal and edentulous. 
Vent oblong or pyriform, basal or marginal, closed by anal plates ; apical disc nearly 
central, four ovarial plates perforated, one imperforate. Ocidars microscopic, tubei'cles 
small and imperforate. 

The existing forms belong to the genus Echinoneus of Van Phelsum, instituted under 
the Dutch name Egelschcitze, and adopted by Leske, Lamarck, Deslongchamps, 
De Blainville, and Desor, to include certain living species of small thin-shelled Urchins, 
with an oval form and a rounded and inflated border. The ambulacral areas are narrow 
and lanceolate; the poriferous zones depressed, and the pores small and unigeminal 
throughout ; the upper surface is flattened, and the apical disc small and excentral ; the 
two pairs of genital plates are perforated, and the single posterior plate is imperforate ; 
the base is concave and curved from before backwards ; the mouth-opening small, oblong. 



PROM THE CHLORITIC MARL. 235 

oblique, and nearly central ; the peristome entire and without auricles, and therefore 
edentulous. A diagnostic character of the family is the periprocte, which is basal and 
pyriform, about the same size as the peristome, and situated between the border and the 
mouth. The tubercles are small and numerous, disposed in regular series, and raised upon 
smooth circular elevations, with perforated summits ; in this we discover another 
organic difference between the Echinonid^ and the EchinoconiDjE. The EcHiNONiDiE 
inhabit the seas of the Antilles, the Philippines, the Trinity, Cuba, Zanzibar, and New 
Zealand, and tests of the same species are found in a semi-fossil state in the calcareous 
tufa of Guadeloupe, Cuba, and Porto-Rico. 

The fossil species are included in the genus Pyrina, which are all found in the different 
stages of the Cretaceous rocks. 



Genus — Pyrina, Desmoulins, 1837. 
Pykina, Globatek, and Nucleopygus, Agassiz, 1837. 

Test oval or round, depressed or globular, sometimes pentagonal or enlarged before and 
narrow behind. Under surface inflated and often depressed around the mouth-opening, 
which is oval, obhque, and inclined from the right to the left side ; this aperture is 
nearly central, and destitute of lobes and auricles. The apical disc is small, compact, 
and nearly central ; it is composed of four perforated genital plates, of which the right 
antero-lateral is the largest, extending into the middle, and supporting the small niadre- 
poriform body. The five small ocular plates are closely wedged into the angles formed 
by the genitals, all the elements of the disc being soldered together. The vent is oval 
and marginal, in general nearer the upper than the under surface. The poriferous zones 
form straight equal narrow linear depressions, all composed of simple pores in regular 
pairs extending from the peristome to the disc. The tubercles are mamniillated and 
imperforate, larger at the under side, and the inter-tubercular surface of the plates is 
covered with a great number of granules. 

Pyrina differs from EcJiinoconiis in having in general an elongated form, the apical 
disc has only four genital plates, the mouth is oval, oblique and edentulous; the 
vent is marginal, and the tubercles are imperforate, whereas in EcUinoconus the disc has 
five genital plates, the mouth is circular or slightly pentagonal, and provided with denti- 
ferous jaws ; the vent is basal or infra-marginal, and the tubercles are maramillated with 
crenulated bosses and perforated summits. 



236 PYRINA^ 



Pyrina Desmoulinsii, (FArcUac, 1847, PI. LIV, fig. 2 a — /. 



Pykina Desmoulinsii, d'ArcMac. Mem. de la Soc. Geol. de France, 2e serie, tome 
ii, p. 297, pi. xiii, fig. 4, 1847. 

— — Agassis et Besor. Catal. raisoime, p. 92, Module T. 86, 

1847. 

— — d'Orbigny. Prodrome, t. ii, p. 178, Etage No. 651, 1847. 

— — Woodward. Mem. of the Geol. Surv., Organic Remains, 

Decade v, pi. vi, fig. a, 1856. 
Pyrina Prattii, Forbes. Morris Catal. Brit. Foss., p. 88, 1854. 

— Desmoulinsii, d'Orlignij. Paleontol. Fran^aise, tome vi, p. 4G7, pi. 981, 

figs. 7 — 11, 1855. 



Diagnosis. — Test tumid, oblong ; ambitus inflated ; posterior border slightly emargi- 
nate ; upper surface depressed ; apical disc small, nearly central ; base concave in the 
middle and pulvinated at the border ; mouth-opening oval, oblique, and nearly central ; 
periprocte elliptical, supra-marginal, nearer the upper than the under surface. 

Dimensions. — Antero-posterior diameter one inch ; lieight half an inch. 

Description. — The test of this rare Urchin is oblong or elliptical, regidar and 
symmetrical, depressed on the upper surface, inflated round the sides, and concave near 
the centre of the under surface. The summit is sub-central, nearer the anterior than the 
posterior border. The ambulacral areas are narrowly lanceolate ; the poriferous zones are 
linear and depressed, and the pores minute, unigeminal, and placed in obhque pairs. lu 
passing across the base the geminal pores become more and more oblique, until they fall 
into a single file and terminate around the peristome. The plates of both areas support 
a number of small equal-sized tubercles ; in fig. 2 e is shown their mode of arrange- 
ment on the ambulacral and inter-ambulacral areas ; they have a quincuncial disposition on 
the plates. The areal space around each is sharply defined, the tubercle is raised on a boss, 
and its summit is perforated. The intermediate surface of the plates is covered with a 
very fine microscopic granulation (fig. ^ (/). The tubercles at the base are much more 
developed than those on the upper surface of the test. Fig. 2 h and fig. 2 i show the 
basal tubercles magnified ; the areal space is deeply excavated out of the structure of the 
plate, and the tubercle is larger than those on the upper surface at fig. 2 i. A portion of 
the test near the mouth-opening is shown with the arrangement of the zones and the 
disposition of the tubercles in this region. 

The mouth-opening is large, elliptical, elongated in the direction of its greatest axis, 
slightly oblique (fig. 2 h), and situated immediately beneath the organic summit. 



FROM THE CHLORITIC MARL. 237 

The vent is elliptical, and placed in the middle of the posterior border (fig. 2 d), 
Jiearer the upper than the under surface (fig. 2 a). 

The apical disc is small, and composed of four ovarial plates, of which the right 
antero-lateral is much the largest, and supports a spongy madreporiform body. All these 
plates are perforated (fig. 2/). The ocular plates, five in number; are small, and well 
wedged in between the ovarials. 

Affinities and Differences. — The regular elliptical elongated form of Pi/rina JDesmou- 
linsii, with its flattened upper surface and pulvinated base^ distinguish this species from 
its congeners. I have compared specimens obtained from the Btage Cenomanien of the 
environs of Tournay, Belgium, with specimens collected from the Chloritic Marl at 
Chard, and find them to be identical in all their details. It very much resembles Pi/rina 
ovidtim, which, however, is a smaller form, with a more inflated test, and the elliptical 
vent is situated near the dorsum. Compare fig. 2 and fig. 3, where the affinities and 
differences are well shown in the admirable figures in PI. LIV. 

It difiers from Pyrina lavis in having a nari'ower test of a more regular elliptical 
figure, and wants the inflation of the anterior portion and the tapering of its posterior 
border. 

Localiiy and StratiyrajMcal Position. — This rare Urchin was collected by Mr. Weistj 
in the Chloritic Marl, near Chard, and Mr. Pratt obtained another from the same locality 
and stratum, which has been beautifully figured in the ' Memoirs of the Geological 
Survey,' Decade v, i)l. vi. The short description was from the pen of my old 
esteemed friend Dr. Woodward, to whom I forwarded all ray materials when he was 
engaged in writing the text for the description of pi. vi of that Decade. 



Pyrina ovulum, Lamarck, sp. PL LIV, fig. 3 a — h. 



NucLEOLiTES OVULUM, Lamarck. Anim. sans vert., t. iii, p. 37, 1816. 

— — Beslongchamps. Encycl. Method., t. ii, p. 500, 1824. 

— — Befrance. Die. des Sc. Nat., t. xxxv, p. 213, 1825. 
Pyrina — Agassiz. Cat. Syst., p. 7, 1840. 

NucLEOLiTES — Desor. Mon. des Galerites, p. 26, pi. v, figs. 35 — 37, 1842. 

— — A(jassizei Desor. Cat. rais. des Rchinides, p. 92, 1842. 

— — (TOrbigny. Prodrome, t. ii, p. 271, 1847. 

— — Morris. Catal. of British Fossils, 2 ed, p. 88, 1854. 

— — Woodward. Mem. Geol. Surv., Decade v, pi. vi, 1856. 

— — Cotteaii. Paleontologie Frangaise, pi. 985, figs. 7 — 11, tome 

vi, p.484, 1855. 



238 PYRINA 

Diagnosis. — Test small, inflated, depressed at the upper surface. Ambitus elliptical,, 
base flattened, margin much inflated ; mouth irregular, pentagonal, oblique, situated in 
the middle of the base ; posterior border sulcated, vent elliptical, elevated near the upper 
surface, plates closely covered with small tubercles. 

Dimensions. — Antero-posterior diameter four tenths of an inch ; height three tenths of 
an inch. 

Descriptions. — The test of this rare little Tyrina is oblong-oval, inflated, rounded 
before, and sulcated behind, for lodging the vent. In its longitudinal profile, fig. 3 d, the 
test is higher behind than before, and always more or less truncated, the upper surface is 
convex and slightly flattened, the under surface is convex and pulvinated, without a depres- 
sion in the centre, the plates are covered with numerous small tubercles larger on the under 
surface, the areas are excavated to receive the boss, which carries a small perforated 
tubercle, fig. 3 g and h. The apical disc is small, composed of four perforated ovarial 
plates and five very minute oculars, fig. 3/. The mouth opening is situated in the 
middle of the base, fig. 3 c, and forms an irregular pentagon with its long axis oblique. The 
vent is oval, situated in a sulcus high up in the posterior border, and the periprocte is much 
nearer the upper than the under surface, fig. 3 h, and fig. 3 e. The poriferous zones 
are extremely narrow, and appear like fine depressed lines on the surface of the shell. 

Affinities and Differences. — This species differs from Pyrina Desmoulinsii in having 
the posterior border sulcated for the vent which occupies a higher position in this 
Urchin. 

Locality and Stratigraphical Position. — It is said to have been collected from the 
lower chalk of Dorsetshire. In France M. Cotteau records it from I'fitage Senonien, he 
collected it in that formation at Saint Christophe, and at Tours, Indre-et-Loire, and at 
Villedieu, Loir-et-Cher. 



Pyrina l^vis, Agassis, 1840. PI. LIV, fig. 1 a — e. 

Galerites l^vis, Agassiz. Cat. Syst., p. 7, 1840. 

— — Besor. Monographic des Galerites, p. 24, pi. iv, figs. 8 — 11,1843. 

— — Agassi:. Cat. rais., p. 91, Module 79, 1847. 

— — (VOrbigmj. Prodrome, t. ii, p. 272, 1847. 
EcHiNOCONUs — d'Orbigny. Revue Zoologique, p. 21, 1854. 

Pykina — Cotteau. Paleontol. Francaise, t. vi, p. 490, pi. 987, figs. 6 — 9, 

1855. 



Diagnosis. — Test subpentagonal, enlarged anteriorly and contracted posteriorly, 



FROM THE UPPER GREENSAND. 239 

■convex above, inflated at the sides and flattened below; vent large, supra-marginal, 
elliptical ; mouth-opening central, opposite the disc ; tubercles small, surface of the plates 
smooth. 

Dimensions. — Anterior posterior diameter eleven twentieths of an inch ; height seven 
twentieths of an inch. 

Description. — This little Urchin appears to be a very rare form, as the example before 
me is the only specimen I have seen in English collections ; the type specimen figured by 
my friend Professor Desor, in his Monograph on the Galerites belonged to M. 
Deshayes and was the only one known to him. 

M. Cotteau has not seen the original, giving copies of Prof. Desor's figure of the test 
and quoting his description of its structure in his ' Paleontologie Francaise.' My 
specimen was collected several years ago from the Upper Greensand near Chute farm, 
Wilts, along with some fine examples of Catopygiis colmnharius and Cottaldia Benettice, 
so that there is no doubt of the horizon of the English specimen. The general outline 
of the test is indistinctly pentagonal, enlarged before and slightly narrower behind (fig. 1 h 
and fig. 1 c). The upper surface is convex, the sides inflated, and the base flat (fig. 1 a ; 
fig. 1 e) ; its height is about one half the length of the test. The plates are covered with 
small tubercles, which are very indistinctly seen ; those at the base are larger. The vent 
occupies the middle of the border ; the periprocte is large, of an elliptical shape, and 
placed a little nearer to the base than the upper surface. The sur-anal carina is only 
slightly developed around the lower part of periprocte. The lower surface is nearly flat, 
with the margin round, and the small mouth-opening is situated in the middle of the 
base directly opposite the vertex. 

Affinities and Differences. — This species is readily distinguished from Pyrina 
Desmoulinsii by its sub-pentagonal form enlarged before and contracted behind; its 
sides are likewise more inflated and the lower angle of the periprocte is nearest the base, 
whilst in P. Desmoulinsii the upper angle of that aperture is nearest the dorsal surface. 

Locality and StratiyrapJdcal Position. — I collected this Urchin from the Upper 
Greensand of Chute Farm, near Wilts, with Catopyyus columbariiis, Cottaldia Benettice, 
and other well-known forms of Urchins and Mollusca belonging to that stratum. 

The type figured by M. Desor was obtained from the Cretaceous rocks of France, and 
as it was communicated to M. Desor by M. Deshayes without the indication of the forma- 
tion from whence it was collected, we are unfortunately in ignorance of its stratigraphical 
position, and as M. Cotteau had not seen the specimen, he was unable to give an opinion 
on the matrix. 



240 



CATOPYGUS 



family 9 — Echinobrissid^, Wri(/]d, 1856. 

Test thin, circular, oblong, sub -pentagonal, or clypeiform, covered with microscopic 
perforate or imperforate tubercles, surrounded by excavated areolas ; ambulacra narrow, 
enclosed by poriferous zones more or less petaloidal ; pores set at different distances apart, 
and imited by connecting sutures. Mouth-opening small, nearly central, pentagonal, 
edentulous, and in general surrounded by five lobes. Vent-opening in a sulcus in the 
upper surface of the single inter-ambulacrum, or in a marginal depression or basal 
portion thereof; apical disc small, with four perforate and one imperforate genital plate ; 
ocular plates very small ; madreporiform body extending into the centre of the disc. 
This family is extremely numerous in genera and species ; two of its representative forms 
are still living — Echinobrissus recens, Edwards, in the Antilles, and Cassidulus Australus,. 
Lamarck, in the Australian seas. 

I include the following genera in this natural family : 



Catopygtjs, Agassis. 
Clypeopygus, d" Orbi(/ny. 
Clypeus, Klein. 
Echinobrissus, Breyniiis. 
Phyllobrissus, Cotteau. 



BoTRioPYGUS, d' Orhigny. 
Trematopygus, d'Orbiyny. 
Rhynchopygus, d' Orbiyny. 
Cassidulus, LamarcJc. 
Caratomus, Jyassiz. 



Genus — Catopycus, Jyassiz, 1837. 

NucLEOLiTES, Lamarck, Goldfuss. 

JDiaynosis. — Test oval or elongated, in general inflated, narrower anteriorly than 
posteriorly ; upper surface convex, summit excentrical anteriorly ; under surface flat or 
slightly convex, and rounded at the border ; posterior half of the test much higher and 
wider than the anterior half; vent situated in the posterior border; periprocte small, 
round, or oval, placed high in a prominent projection of the inter-ambulacrum at the summit 
of a vertical truncation of the area. Mouth-opening small, situated nearer the anterior 
than the posterior border ; pentagonal in form with equal elongated sides, having one angle 
anterior, and surrounded by five prominent lobes (PI. LV, fig. 2 h) ; between the lobes 
a rosette is formed of five depressed leaves, crowned with minute granules and unequal 



FROM THE UPPER GREENSAND. 241 

buccal pores, some double externally, others small internally. Ambulacra narrow, 
sub-petaloid, straight, more or less elongated, and open at the lower extremity ; poriferous 
zones composed of an inner series of round pores, and an external series of elongated 
pores arranged in conjugate pairs (fig. 2 cj) ; tubercles very small, raised on mammillated 
bosses (fig. 2) in many horizontal lines on the surface of the dorsal plates, those at the 
base being larger. Apical disc small, prominent, formed of four perforated ovarial plates 
and five microscopic oculars, the madreporiform body projecting from the surface 
(fig. 2/). 

Affinities and Differences. — Calopi/pis differs from Cli/jjeopi/ijus and Echinohrissus by 
its oval form, convexity of the upper surface, inflation of the sides, and flatness of the base, 
by its pentagonal mouth, with five prominent sides and rosette of pores between the 
lobes, and its small round periprocte opening high in a prominent vertical truncation of 
the single inter-ambulacrum. 

The genus Catopygii,s appertains to the Cretaceous rocks, and is a very characteristic 
fossil in its different divisions. In the Gault or Albiau stage of the Mediterranean basin 
Catopi/ffus ci/IindricHs has only hitherto been found. 

In the Upper Greensand or Cenomanian formation C. columharius prevails throughout 
the Anglo-Parisien and Mediterranean basins. 

In the Lower Chalk or Turonian C. EhraijanusK?, found. 

In the Middle Chalk or Senonian eight species have been collected in France, Avhere 
many of the beds of this division attain a development unknown in England, and contain 
a fauna of the most remarkable forms. The C. suh-carinahis and ehngahis are found 
simultaneously in the Anglo-Parisian and Pyrenean basins, although C. Icevis, fenes- 
tratus, conformis, pyriformis, ohtusus, and affinis, are discovered only in the Parisian basin. 

This genus, therefore, attained its greatest development in the seas which deposited 
the White Chalk with flints, and became extinct with the close of the Cretaceous epoch, 
as Catopiygus is not found in the Tertiary rocks nor in the waters of the present 
time. 



Catoptgtjs columbarius, LamarcJc, 1816. PI. LV, fig. 2 a — i. 

EcHiNiTEs PYRiFOEMis, ParMnson. Organic Bemaius, vol. iii.tab.iii, fig. G, ISll. 
NucLEOLiTES coLUMB.iiiiA, Lamarck. Anim. sans Vertebres, t. iii, p. 37, 1816. 

— — Deslonffchamj). Encyl. Method., t. ii, p. .5/0, 1824. 

— — De/rance. Die. des Sciences Nat., t. xxxv, p. 313, 182.5. 

— CAiuNATUS, Goldfuss. Petrefacta Germanise, b. i, p. 142, pi. xliii, fig. 

11, 1826. 

— coLUMBAKiA, BlainvUle, Die. des Sciences Nat., t. Ix, p. 188. 1830. 

31 



242 CATOPYGUS 

Catopygus carinatus, Agasdz. Prodrome Echinides, p. 18, 1836. 
NucLEOLiTES COLTJMBAKIA, DesmouUns. Etudes sur les Echinides, p. 356, 1837". 

— CARINATUS, d'Archiac. Mem. Geol. Soc. de France, p. 180, 1837. 
Catopygus — Bronn. Letbse Geognostica, p. G13, 1837. 

— — Milne-Edwards. In Lamarck, 2e ed., t. iii, p. 351, 1840. 
NnCLEOLITES COLUMBARIA, Ibid. Ibid., 344. 

Catopygus carinatus, Agassiz. Cat. Syst., p. 4, 1840. 

— — Roemer. Norddeuts-Kreide-Gebirges, p. 32, 1840. 
Catopygus CARINATUS, Morris. Catalogue of British Fossils, p. 49, 1843. 

— coLUMBARius, d'Archiac. Mem. Soc. geol. France, p. 296, 1847. 

— — Ayassiz et Desor. Cat. raison., p. 100, Modele R 71 

1847. 

— — d'Orbigny. Prod., t. i, p. 1/8, Stage 20, 1847. 
NucLEOLiTES CARiN.iTUS, Forbes. Mem. Geol. Surv., Decade i, pi. 1 0, 1849. 
Catopygus — Sorignet. Oursins del'Eure, p. 43, 1850. 
NucLEOLiTES — Quenstedt. Handbuch der Petrefact., p. 586, pi. xlix, 

fig. 51, 1852. 
Catopygus • — Bronn. Leth. Geogn., 2 ed., p. 196, pi. 29^, fig. 16, 1852. 

— — Albin Gras. Catal. des Corps org. de I'Isere, p. 40, 1852. 

— — Morris. Catal. of British Fossils, 2 ed, p. 74, 1854. 

— COLUMBARIUS, Co^ieaM. Pal. Frang. Ter. Cret., t. vi, p. 436, pi. 970, 1855. 



Diapiosin. — Test oval or subrotund, contracted anteriorly, enlarged and truncated 
posteriorly, sides inflated, dorsal surface unequally convex, base nearly flat, ambulacra 
narrow, dorsal, subpctaloid and open below; inter-ambulacra wide, single inter-ambulacrum 
narrow, elevated, and truncated, vent round in the upper border, above the periprocte 
an obtuse carina which terminates in the projecting upper border of the vent ; mouth- 
opening small, excentral nearer the anterior border, peristome surrounded by five prominent 
lobes and a rosette of pores between them. Apical disc excentral nearer the anterior 
border, the vertex in general behind the apex. 

Dimensions. — I have selected six good typical forms showing the varying proportions 
of this species. 





1 


2 


3 


4 


5 


6 


Length 


1 


fill 


nio 

"l2 


OA 


OA 


Ol^2 


Height . 


AJ-O 
^12 


m 


^12 


OA 


OA 


o-A 


Breadth . 


^ 


Oi^ 


^ 

»^12 


OA 


OA 


Ox^ 



Description. — The table of synonyms exhibits the changing views of naturalists in 
respect to this beautiful Urchin. Goldfuss, who gave the first good figure of the species, 
cites, with doubt, its identity with Nucleolites colmnharius, Lamarck, but the brief diagnosis 
in ' Hist. Nat. des Anirn. sans Vert.,' taken in connection with the locality and stratum 
from whence it was collected, " les environs de Mans/' so well known for its beautiful Upper- 



PROM THE UPPER GREENSAND. 243 

Greensand fossils, has satisfied me, after a comparison of specimens in my collection from 
that locality with a series of type tests from the Upper Greensand of Wilts and Dorset, that 
the two Urchins appertain to the same species, and that Lamarck's name ought to be 
retained. Catojiygus columbarius, it is true, assumes a considerable variation of form as 
regards the elongation, shortening, height, breadth, and inflation of the test, so that there 
is field enough for species-makers, who attach undue importance to these characters, to make 
several varieties out of a handful of specimens. These phases of form appear to me to 
have depended on the physical conditions which surrounded the life of the Urchin, and 
have nothing whatever to do with the specific characters I have pointed out in my 
diagnosis of the species. 

The test is ovate or subrotund and always wider behind than before; the dorsal 
surface is tumid, varying in the degree of its elevation ; in some specimens it is sub- 
depressed and declines anteriorly, in others it is subconic and much elevated in the centre, 
the true apex being almost the apical disc, whereas, in general, that body is excentral and 
situated before the vertex, which is formed by the ridge of the single inter-ambulacrum. 
The sides are rounded and more or less inflated, and the posterior extremity is truncated 
more or less abruptly. A more or less developed obtuse central elevation extends along 
the ridge of the single inter-ambulacrum to the upper border of the vent, where it forms 
in many examples a prominent apicnlated arch over the periprocte, PI. LV, fig. 2 d. In 
all the specimens I have examined this prominence exists, but its degree of development 
varies much. The ambulacral areas are narrowly lanceolate, limited to the dorsal surface* 
subpetaloid, and very uniform in their proportions in all the varieties. The single area 
and anterior pair are nearly equidistant from each other, but the posterior pair are more 
distant from the anterior pair, and are placed much closer together than the others and extend 
backwards. The number of pairs of pores in each zone is nearly equal, varying from 
twenty-eight to thirty in well-grown adult shells ; the pores in the outer row are elongated 
and oblique, and in the inner pores are round and appear to be conjugated by fine 
olilique sutures. At the lower part of the petals the pores become smaller, and are set 
much wider apart as they pass round the border of the test and extend to the peristome. 
The ambulacral plates are narrow in the petaloid portion of the zones, and become 
much larger and broader beyond the petals ; each plate has its pair of holes which 
can be distinctly traced in good specimens, and they form the true poriferous zones on 
the sides and base of the test. PI. LV, fig. 2 h, c, d, <?, shows these poriferous zones. 
Around the mouth the pairs of pores again form petals as on the dorsal surface, and they 
are here so arranged that they form ten short petaloidal ambulacra, forming rosettes 
around the mouth, and constructed like those on the dorsal surface. Fig. 2 h shows this 
structure extremely well in a drawing magnified six diameters. 

The wide inter-ambulacral areas arc formed of large oblong plates, the surface of 
which, as well as those of the ambulacra, are covered with minute moniliform tubercles, 
interspersed with microscopic granules. Pig. 2 g shows the arrangement of the tubercles 



244 ■ CATOPYGUS 

and granules on the ambulacral and inter-ambulacral areas magnified six times ; and 
fig. 2 exhibits the more developed form the tubercles assume on the basal plates, and the 
manner they are encircled by rows of granules. It is only on very fine specimens, such 
as some I have obtained from the Chloritic Marl of Chard, that I have been able to see the 
surface anatomy of the plates, such as I have figured and described it; the Upper- Greensand 
fossils are spoiled by the matrix, and are quite unfit for such minute observations. 

The small apical disc is, in general, excentral, and the madreporiform body occupies 
the centre, covers the plates, and forms a prominence ; there are four perforated genital 
plates, and five distinct ocular plates (fig. 2 h and fig. 2 /). The two anterior genital 
holes are placed nearer together than the posterior pair. 

The ventral surface is slightly convex, or nearly flat; the tubercles are much larger in 
this region, and exhibit the arrangement shown in fig. 2 i, where each tubercle rises on 
the surface of a rounded boss and is encircled by a ring of granules (fig. 2 c). The 
mouth-opening is excentral and nearer the anterior border, the peristome is pentagonal and 
surrounded by five prominent tubercles which form the termination of the inter-ambulacral 
areas (fig. 2 c). From the inter-lobular spaces ten short petaloid ambulacra proceed, and 
these collectively form rosettes around the peristome, as shown in fig. 2 h, where this 
structure is drawn magnified six diameters. 

The vent opens in the upper portion of the truncated posterior border in a well- 
defined vertical area; it is oblong, and varies in size in different specimens, but is always 
small in proportion to the size of the test. 

The periprocte is prominent, especially in the upper border, which, in some specimens, 
overhangs the vent in a beak-shaped fashion (fig. 2 ^). 

Affinities and Differences. — This species is found in the Upper Greensand or 
Cenomanian stage throughout the Anglo-Parisian and Mediterranean basins, and it is the 
only form of Catojjygus hitherto collected in this stratum in England ; its characters are so 
definite and distinct that there is no difficulty in distinguishing this species from its 
congeners. 

Locality and Stratigraphical Position. — It has been collected from the Upper Green- 
sand of Warminster and Chute Parm, Wiltshire ; Ilythe, Kent ; and from the junction beds 
of Upper Greensand and Chalk-marl at Maiden Bradley, Wiltshire ; and from the Chloritic 
Marl, near Chard, whence my best specimens were obtained. The foreign distribution of 
this species, according to M. Cotteau, is from the Cenomanian or 20th stage of d'Orbigny, 
the equivalent of the Upper Greensand of English authors. In France it is common at 
Mans, Coulaines, Saint-Calais, and Condrecieux, Sarthe ; Villers, Trouville, Calvados ; 
Havre, Seine-Inferieure ; Grace, Orne ; Vierzou, Cher; Chinon, Indre-et- Loire ; Fouvas 
and Bel-Air, near Pvochcfort, and other localities. In Belgium in the Tourtia of Tournay ; 
in WestphaUa at Essen on the Ruhr. 



PROM THE LOWER GREENSAND. 245 



Catopygus Vectensis, Wrif/Jif, nov. sp. PL LV, fig. 1 a — d. 

Diagnosis. — Test oblong, contracted posteriorly ; dorsal surface flat and convex, 
elevated towards the narrow posterior border; sides inflated, base concave; ambulacra 
narrow, lanceolate, dorsal, subpetaloid, and open below ; inter-ambulacra wide, single 
inter-ambulacrum narrow, slightly elevated ; posterior l)order truncated ; vent oblong, 
in the upper third ; an obtuse elevation of the dorsal portion, bifurcating at the 
periprocte, sends down a carina on each side of the vent, which extends to the 
margin. Apical disc nearly central, four perforated genital plates ; madreporiform body 
small, central. 

Dimensions. — Length one inch ; breadth eight tenths of an inch ; height unknown. 

Description . — This species has much resemblance to certain varieties of Catopygus 
columbariiis but a careful comparison between it and the most allied forms of that 
species shows that Catopggus Vectensis possesses distinct characters of its own. It is, I 
believe, the oldest form of the genus Cafojjggus at present known. The outHne of the test 
is nearly a regular oblong, rather more contracted posteriorly (PI. LV, fig. 1 a, b). It is 
moderately elevated and a little higher at the posterior border (fig 1 c) ; the sides are 
inflated (fig. 1 d), and the base is concave; this portion of the test is partially covered 
by closely adherent matrix in the best specimen, and broken in the other, so I must 
speak with reservation regarding the specific characters of this region. The ambulacral 
areas are narrowly lanceolate (fig. 1 b, d), and the long subpetaloid poriferous zones extend 
over the dorsal surface, a character which is very well drawn in figs. 1 a, b, c, d; the 
traject line of the pores is indicated by the sutures in which they are placed, but the 
pores themselves cannot be satisfactorily made out in consequence of the imperfect 
preservation of the areal plates. 

The inter-ambulacral areas are built of long plates ; those on the upper surface had 
veiy small tubercles which appear to have been more developed at the base ; the posterior 
single inter-ambulacrum has an elevated ridge on the mesial line which extends to the 
upper border of the vent (fig. 1 o), and then divides into two branches (fig. 1 d) ; which 
descend to the border, the whole forming a kind of miniature Gothic arch, having 
the oblong vent in its upper third (fig. 1 c and d). 

The apical disc is nearly central (fig. 1 b), and lower than the vertex (fig. 1 c) ; it is 
small, has four genital holes drilled around a small central button-shaped madreporiform 
tubercle. 

The mouth-opening is excentral and anterior ; it is too much concealed by hard rock 
to be exposed without risking the fracture of the shell, so the anatomy of the peristome 
cannot be made out. 

Affinities and Differences. — This species differs from C. cohmbarius in the following 



246 CLYPEOPYGUS 

characters : — The shell tapers behind, is not so elevated, has a flatter dorsal sui-face and 
less prominent central ridge in the inter-ambnlacrum ; the apical disc is more central, and' 
the contour indicates a flatter form with less inflated sides. 

Locality and Stratigrapliical Fosition. — This new species was collected by the Kev. 
T. Wiltshire, P.G.S., from the Lower Greensand (Neocomian) at Shankhn, Isle of 
Wight. 



Genus — Cltpeopygus, A. cTOrbirjny, 1856. 

NucLEOLiTES (pars), Ayassh, Besor, Cotteau. 
EcHixoBKissus (pars), Be Loriol. 
CATOPYGns (purs), Jffassis. 

Diagnosis. — Test oblong, more or less depressed, upper surface convex, mider surface 
concave, mouth-opening excentral, nearest the anterior border ; peristome surrounded by 
five rosettes of buccal pores, and separated by five prominent lobes, oral aperture regular, 
pentagonal, with equal sides and a prominent angle anteriorly. Vent small, situated in a 
deep groove with perpendicular walls and well-defined outline, extending nearly half way 
up the dorsal surface of the single inter-ambulacrum, ambulacra narrowly lanceolate, and 
subpetaloidal ; the anterior and posterior pairs, especially the latter, long and flexuous. 
The pores which compose the zones are sometimes imequal, the .external series being 
more or less elongated in a transverse direction ; apical disc small, excentral, and 
composed of four perforated, and one imperforate genital plates, the right antero-lateral 
supporting the madreporiform body, which extends into the middle of the disc and forms 
a prominence there; the five ocular plates are small and angled into the summits of 
lanceolate ambulacra. The tubercles are very small and set closely together on the 
upper surface (PL LVI, fig. 1/), and larger on the under surface (PL LVl, fig. 3 _^) ; 
they are all encircled by areal depressions and separated by minute granules. 

This group was separated by M. A. d'Orbigny from Echinobrissus in consequence of the 
following characters, which he observed to be constant in all the species : — The large central 
polypiform madreporiform body; the mouth-opening surrounded by five rosettes of 
pores, alternating with five well-developed buccal lobes; and the anal sinus circum- 
scribed and contracted. 

The species are all special to the Cretaceous formations. M. d'Orbigny described 
and figured six from the Neocomian and two from the Albian stages, and I now add 
another form from the Neocomian of the Isle of Wiatht. 



PROM THE LOWER GREENSAND. 247 



Clypeopygus Fittoni, Wrigld, nov. sp. PI. LVI, fig. 1 — 3. 

Test oblong, upper surface depressed, highest posteriorly ; under surface concave ; 
ambulacra narrow, lanceolate ; poriferous zones subpetaloidal above and narrowly biserial 
on the sides and base ; apical disc nearly central ; vent-opening at the end of a narrow 
sinus with vertical walls ; mouth-opening at the junction of the anterior with the middle 
third, peristome surrounded by five prominent lobes and five pairs of subpetaloidal 
pores, forming together a well-marked rosette. 

Dimensions. — No. 1, length I^^q- inches, breadth 1 inch; No. 2, length 1-^- inches, 
breadth \-^ inch. 

DescrijJtion. — The outline of the test is oblong, with the sides slightly compressed ; 
the upper surface is convex, flattened at the anterior half, and gradually elevated towards 
the posterior third, which is the highest part of the test (PI. LVI, fig. 1 (/, fig. 3 e) ; from 
this point it bends abruptly down to the posterior border; Mr. Bones' capital figures 
in PI. LVI make this character of the test far more intelligible than the most laboured 
description could effect. 

The ambulacral areas are narrowly lanceolate, the antero- and postero-lateral pairs 
are long and flexuous, and the single area is short and straight ; the poriferous zones 
(fig. 3 /) are slightly subpetaloidal on the dorsal surface (fig. 1 b, fig. 3 b), and closely 
biserial on the sides and at the base (fig. 1 d, e, fig. 1 c, fig. 3 c) ; as they approach the 
peristome, they expand and form five petaloidal expansions around the mouth, which are 
separated from each other by the five lobes that surround the oral opening (fig. 3 c). 

The inter-ambulacral areas are largely developed ; the antero-lateral are the narrowest, 
the postero-lateral the widest, and the single area of intermediate width ; they are built of 
large plates bent in the middle, having their surface closely covered with small scrobicu- 
lated tubercles arranged in horizontal rows ; fig. 1 / shows three of these jjlates and a 
corresponding portion of the ambulacral area with the poriferous zones, magnified six 
diameters. The tubercles at the base are larger and wider apart than those on the 
upper surface, as shown in fig. 3 ff, where a portion of the base is magnified three 
diameters ; the boss, area, and imperforate tubercle are well seen in this drawing. 

The vent opens at the end of a deep sulcus near the middle of the dorsal portion of 
the single inter-ambulacrum-, see figs. 1 b, c, fig. ^ b,d; the walls of the sulcus are 
abruptly perpendicular (fig. 3 b, d, c), and the oval periprocte is seen at the upper portion 
thereof (fig. 1 e, fig. 3 b, d) ; the single inter-ambulacrum exceeds in height all the others, 
for its upper surface is elevated (fig. 1 a), and forms the vertex of the test, whilst its 
under surface is curved downwards and forms a marked prominence in the base 
(fig. 1 d, e, fig. 3 a, e) -. I have not seen the apical disc well shown in any specimens. 



248 ECHIA^OBRISSUS 

The base is concave, and the mouth-opening occupies a deep depression at the 
junction of the anterior with the middle third of the base (fig. 3 c) ; the development of 
the five oral lobes, and the five alternating, petaloidal rosettes impart a remarkable 
generic character to the only specimen in which this portion of the anatomy of the test is 
satisfactorily exposed. I have given a figure of this structure, as all the other specimens 
have the base covered more or less with the coarse grains of the matrix. 

Affinities and Differences. — This species resembles Clypeopyrjus Cerceleti,^Oxh.,\\\ all 
the chief points of its anatomy, but differs in the following particulars : — C. Fiifonihas 
the test more oblong or subquadrate, and not enlarged posteiiorly ; the single inter- 
ambulacrum is more developed, rises higher on the upper surface, and curves lower 
on the under surface than in d'Orbigny's figure of C. CerceMi. 

Locality and Stratic/raphical Position. — This rare Urchin was collected from the 
Lower Greensand of Shanklin, Isle of Wight, by the Rev. T. Wiltshire, F.G.S., and 
myself. I have dedicated the species to the memory of my old friend Dr. Fitton, 
F.R.S., whose admirable monograph on the Lower Greensand of the Isle of Wight will 
long remain a text-book to the explorers of this classical geological region. 



Genus — Echinobrissus, Sreynius, 1732. 

KucLEOLiTES, Lamarcl', 1801. 

— Goldfuss, 1S2G. 

— Agassi:, 1837. 
Echinobrissus, d'Orbiymj, 1855. 

— Desor, 1857. 

— Cot fern, 1858. 

— J)e Loriol, 1868. 

This natural group is composed of small Urchins which have an oval, oblong, subquadrate, 
or subcircular form, more or less convex on the upper surface, and slightly concave at 
the base ; the test is obtusely rounded anteriorly, more or less produced, truncated, or 
lobed posteriorly, and in general is nari'ower at the anterior than the posterior third ; the 
vent opens into an anal sulcus which in one group extends from the apical disc to the 
posterior border, and in another is limited to the lower third of the inter-ambulacrum ; 
the periprocte was closed by a series of small anal plates usually absent in fossil forms, 
but preserved in the only living descendant of the genus. 

The base is more or less concave ; the mouth-opening is small, pentagonal, 
excentral, and lodged in an excentral depression ; in one group the peristome forms 
a regular pentagon ; in another group it is directed obliquely across the test. 



FROM THE UPPER GREEN SAND. 24^ 

D'Orbigny has separated the latter into a distinct genus under the name Trematopypis, 
all of which are special to the Cretaceous Rocks ; and they form a convenient section of 
the genus, although the characters on which the separation is based are, from my point of 
view, too slight and evanescent to form a stable generic basis. The apical disc is small, 
quadrate, and compact ; it is composed of four perforated and one imperforate genital plute, 
the right antero-lateral, supports the madreporiform body ; the five oculars are very small 
and triangular, and are wedged in between the genitals and apices of the lanceolate 
ambulacra. 

The tubercles are small, with perforated summits and depressed areas, and the 
surface of the plates is covered with microscopic granulations. 

The genus Echinobrissus was established by Breynius in 1732 in his important 
memoir ' De Echinis et Echinitis,' and of which I have given a translation at p. 193. 

Klein, who published only two years afterwards, did not, unfortunately, preserve the 
well-defined genera proposed on such good characters by his learned contemporary ; 
and Leske, his commentator, in 1778 placed the Ecldnohrissus of Breynius under the 
Spataiiffus of Klein. When Lamarck in 1801 proposed the genus Nudeolites in the 
first edition of his great work, he was not aware that the same group of Urchins had 
been well figured and accurately diagnosed si.xty-nine years before by Breynius ; but in 
the second edition of ' Animaux sans Vertebres ' a reference was made to this work for 
figures of the species. The late Professor Agassiz in dismembering Lamarck's Nudeolites 
unfortunately did not restore Breynius' genus, although, as a rule, Agassiz adhered to the 
genera of the older naturalists. To the late Professor A. d'Orbigny the honour is due 
of vindicating the claims of Breynius's work, and which all subsequent Echinologists, 
Desor, Cotteau, and De Loriol, have rigidly observed. 



Echinobrissus lacunosus, GoWfuss} 1S29. 

KucLEOLiTEs LACUNOsus, GolJfuss. Petref. Germanise, pi. .\liii, fig. 8, p. 141, 1 829. 

— — Besmoulins. fitiides sur les Echinides, p. 360, 1837. 

— — Morris. Cat. of Brit. Foss., p. 55, 1843. 

— — Agassis et Desor. Cat. raison., p. 97, 1847. 

— — Forbes. Mem. Geol. Survey, Decade i, p. 8, 1849. 
Echinobrissus — d'Orbigny. Pal. Franc. Ter.Cret., pi. 958, figs. 7— 10, 1855. 

Bia(jnosis. — Test ovate, obtuse anteriorly, subquadrate and subtruncate posteriorly, 
sides subcompressed ; upper surface convex, vertex subcentral or supra-anal ; ambulacra 
narrowly lanceolate; anal sulcus deep, short, oblong, and abruptly declined; inter- 
' No specimen has been found hitherto sufficiently perfect for the purpose of illustration. 

32 



250 ECHINOBRISSUS 

ambulacrum subdepressed, recurved ; base concave ; mouth-opening surrounded by five 

short petaloid poriferous zones. 

Dimensions. — Length seven tenths of an inch ; breadth half an inch. 

Description. — The test of this species is obtusely rounded before, and subquadrate 

and truncated behind ; the sides are shghtly compressed, and the posterior third is the 

widest part of the ambitus. The upper surface is convex and the under surface concave, 

and inclined upwards towards the posterior border. 

The ambulacral areas are narrowly lanceolate, and the dorsal poriferous zones slightly 

subpetaloidal on the sides and base ; the pores are scarcely visible on the upper surface, 

but around the mouth they form a five-rayed star of short petaloidal pores, with five oral 

lobes between them, as in Cli/peopi/(/us. 

The apical disc is small and excentral; four of the ovarial plates are perforated. 
The surface is covered with scrobiculated tubercles. The mouth is situated at the 
jimctiou of the anterior with the middle third, and is surrounded with the short rosette 
of pores already described ; the base is concave between the sides, and curves upwards 
towards the anterior and posterior borders, so that the borders of the postero-lateral inter- 
ambulacra are convex and prominent at the sides and base, and impart to this Urchin one 
of its best diagnostic characters. The anal sulcus is short, deep, oblong, and abruptly 
declined, and occupies the region above the posterior border of the inter-ambulacrum ; 
the vent opens at the extreme end of the sulcus above the middle of the test. 

Affinities and Differences. — This Urchin was well figured by Goldfuss, and much 
resemljles Echinohrissiis similis, d'Orbigny, which appears to be a large variety of 
JS. lacunosus. It resembles E. Boberti, Gras, from the Upper Neocomian, but is 
distinguished from that form by the following characters : the anal sulcus is lower, 
narrower, and nearer the border ; the sides are less inflated and more compressed ; and 
the base curves more upwards posteriorly. 

Localitij and 8traii(/raphical Position. — This Urchin has been long collected in 
the Upper Greensand at Longleat, Wilts, and from the Chloritic Marl at Chardstock; 
the type-specimen was obtained from the Chalk-marl near Essen on the Ruhr, 
Westphalia. 



EcHiNOBRissus MoRRisii, Forbcs, 1849. 

Cassidulus LAPis-CANCRi, Morris. Cat. Brit. Foss., p. 49, 1843. 
NucLEOLiTES MoKEisii, Forbes. Mem. Geol. Surv., decade i, p. 8, 1849. 

— — Morris. Cat. Brit. Foss., 2 ed., p. 84, 1854. 

EcHiNOBEissus — d'Orbigny. Pal. Frau9. Ter. Cretaces, pi. 959, 1854. 

Diagnosis. — Test oblong, anterior and posterior borders obtusely rounded; sides 



PROM THE UPPER GREENSAND. 251 

compressed, dorsal surface convex ; ambulacra lanceolate, subpetaloidal ; apical disc 
excentral and forwards ; vertex central ; anal sulcus short, deep, and subtriangular ; base 
concave ; mouth-opening pentagonal, slightly excentral, and forwards. 

dimensions. — Antero-posterior diameter half an inch ; height three tentlis of an inch. 

Description.- — -The test is oval and depressed, obtusely rounded before, a little 
angular, subrostrated, and sloped out behind, and the greatest diameter is at the pos- 
terior third. The upper surface is convex ; the longitudinal profile shows it to be rounded 
and depressed at both extremities, with a slight excentral elevation nearer the anterior 
than the posterior border. The ambulacra are long, lanceolate, and subpetaloidal on the 
dorsum, narrower at the ambitus, and enlarged in the base ; the poriferous zones have the 
pores unequal, and a little apart above where they form the petals ; they are close together 
and microscopic at the ambitus, and are larger and more numerous near the mouth, where 
they form a pentagonal star around the peristome. The anal sulcus occupies the lower 
fourth of the single inter-ambulacrum ; it is short, deep, and triangular, and its two 
lateral walls form prominent carinaj, the sulcus making an excavation in the posterior 
border ; the vent is oval and opens at the summit of the valley. 

The apical disc is small, quadrate, with four perforated genital pores ; it is slightly 
excentral and placed a little forwards, and forms the vertex of the test. 

The base is very concave, always near the mouth, and greatly undulated at the sides, 
the single inter-ambulacrum being slightly subrostrated and recurved. 

The mouth-opening is excentral, the peristome pentagonal, with one angle directed 
forwards, and the pores increase in size and number in the ten zones around this 
aperture. 

The scrobiculated tubercles closely cover all the upper surface ; beneath they are larger 
and not so numerous. 

Affinities and Differences. — This species, which is very rare in England, was said by 
the late Professor A. d'Orbigny to resemble E. Bour(juigncdi, but to be distinguished 
from it by having the test much more depressed, subrostrated behind, compressed at the 
sides, humped at the vertex, and more concave and undidated on the under surface. 

Locality and Stratiyraphical Position. — According to the late Professor Porbes, who 
first separated the species from E. lacunosus, and gave only an imperfect diagnosis without 
any figure of the same, this Urchin is found in the Upper Greensand of Warminster and 
Blackdown, and the type was detected in Professor Pennant's collection. On the Continent 
it was collected by the late Vicomte d'Archiac from " I'Etage Cenomanien" at Brunswick. 
Unfortunately the figure of this species was not drawn by my late lamented friend 
Mr. Bone, as he was waiting to procure a good specimen to draw, and had not obtained 
one when it was required. 



TREMATOPYGUS 



Genus — Trematopygus, A. d'Orhigny, 1855. 

NucLEOLiTES (pars), Agassiz. 
EcHixoBBissus (pars), Desor. 
Phvllobrissus (pars), Cotteau. 
— (pars). Be Loriol. 



Form of tlie test ovate or oblong, a little contracted and rounded before, and more or 
less enlarged behind. 

Upper surface convex, ambitus inflated, posterior inter-ambulacrum slightly ros- 
trated. 

Apical disc quadrate, excentral, and nearer the anterior border, composed of four 
perforate ovarial and one single imperforate plates ; the madreporiform body covers the 
genital elements and forms a prominence in the centre of the disc ; the five ocular plates 
are very small and closely united to the genitals. 

The ambulacra are long, lanceolate, and well defined throughout ; the poriferous 
zones are subpetaloidal on the upper surface ; the outer rows of the dorsal pores are 
elongated transversely at the ambitus and base, they are equal, biserial, and microscopic, 
and around the peristome a few supplementary pairs are present, which are larger and 
more conspicuous than the others. 

The inter-ambulacra are built of large plates bent in the middle, having their surface 
covered with two or three irregular rows of tubercles, which are perforated, raised on 
mammelons, and encircled by depressed areas having circles of granules around them, 
and the inter-tubercular surface is covered with a fine granulation. 

The anal sulcus is large, shallow, and limited to the posterior border ; the vent is 
large, oval, or pyriform, and opens near the surface. 

The base is flat or slightly concave towards the middle ; the mouth-opening is 
irregularly pentagonal, compressed obliquely from left to right, and from above down- 
wards. 

Treniatoj)ijgus is only a sectional group of the genus EchinobrissKs, characterised by 
an oblique compressed peristome, and by the large elongated vent placed in a marginal 
shallow sulcus. 



FROM THE LOWER GREENSAND. 353 



Trematopygus Faringdonensis, Wriffht, 1871. PI. LVII, fig. 1 a — h. 

Trematopygus Faeixgdonensis, Wright. In Phillips' Geology of Oxford, p. -134, 

1871. 

Diagnosis. — Test gibbous, oval, much inflated at the sides and base, narrow in the 
anterior, and enlarged in the posterior third. Apical disc and vertex excentral and for- 
wards ; ambulacra lanceolate, dorsal pores snbpetaloid, and sulcus excavated out of the 
posterior border ; vent pyriform, large; base concave, sides undulated by the inflation of 
the inter-ambulacra ; mouth-opening large and oblique, and situated at the junction of 
the anterior with the middle third. 

Dimensions. — a. Length one inch and three tenths ; height seven tenths of an inch ; 
lireadth one inch and two tenths, h. Length one inch and five tenths ; height seven 
tenths ; breadth one inch and three tenths. 

Description. — The test of this rare Urchin has an oval outline, is a little narrower 
before than behind, and is much inflated at the sides and base. The upper surface is 
convex with the vertex excentral and forwards, fig. 1 a and b. 

The ambulacra are long, lanceolate, unequal, petaloid ; the posterior pair are much 
longer than the others, and the single area is the shortest and narrowest ; at the under 
surface the ambulacra form depressions, and the inter-ambulacra elevations, so that the 
base is undulated at the sides and concave in the middle, fig. 1 c. 

The poriferous zones are well developed at the upper surface and the external rows 
are slightly elongated, fig. \ h ; at the ambitus and base the pores are small and closely 
biserial, and become larger and more conspicuous around the peristome, fig. 1 c. 

The apical disc is small and quadrate, fig. 1 a, h ; the four genital plates are perfo- 
rated, and the anterior pair set closer together than the posterior pair ; the madreporiform 
body occupies the middle of the disc and forms a prominent button there. The ocular 
plates are very small and closely united to the other discal elements, see fig. 1/, where the 
disc is shown magnified six diameters. 

The periprocte is pyriform or oval, and acuminated at the upper extremity, fig. 1 
a, b, and e; it is quite supra-marginal ; the anal sulcus makes a deep indentation in the 
posterior border, fig. 1 b, d, e, and from its sides two carinas proceed towards the base, 
fig. \e. 

The tubercles are prominent and perforated, and raised on bosses surrounded by 
depressed areas, the margins of which are encircled by granules, and all the inter- 
tubercular surface is covered with a well-developed granulation, fig. Iff; at the base 
the tubercles are larger and more spaced out, the raammelons are larger, and the granules 
surrounding the areas more developed, fig. 1 h. In fig. 1 y an arabulacral area with the 



I 
254 CARATOMUS 

poriferous zones together Avith a portion of inter-ambulacra is shown, consisting of 
three plates magnified six diameters ; the arrangement of the tubercles is most accurately 
given, and their relative size and structure well shown in this drawing. 

Afinities and Differences. — This species resembles very much Trematopygus C'amjrl- 
cheanus, d'Orbigny. Our Urchin is larger and more gibbous, and the anal sulcus wider 
and more developed ; the base likewise is more undulated, from the inflation of the basal 
portions of the inter-ambulacra ; and the arrangement of rows of granules above the pores 
in the poriferous zones, ' Pal. Fran^aise,' pi. 950, fig. 0, is absent in T. Farinc/donensis. 
In the absence of specimens with which to compare these nearly allied forms, it is 
impossible to decide whether they are specifically distinct or only varieties of T. Olfersii. 

Locality and StratigrajMcal Position. — I have collected this Urchin only in the Sponge- 
gravel beds of Lower Greensand at Coxwell, near Faringdon, Berks. The fine specimen, 
fig. 1 a, was obtained from this locality, and presented to me by my old esteemed friend 
Thomas Davidson, Esq., F.R.S. I am likewise indebted to E. C. Davy, Esq., F.G.S., 
Wantage, for several specimens more or less perfect to complete my description of 
the anatomy of the test of this very rare form. It is worthy of note that the group to 
which I refer the species all come from beds appertaining to the Middle Neocomian, 
"Etaye Neocomien vioyen," a fact of importance helping to determine the age of the 
Sponge-gravel beds of Berkshire. 



Genus — Caratomus, Ayassiz, 1840. 

Small Urchins Avith an ovoid or circular test rounded before and often rostrated 
behind ; the sides are thick and inflated, the upper surface is convex, and the apical disc 
excentral and forwards ; the base is convex with a slight depression arftuud the mouth- 
opening, which has neither lobes nor pores. 

The vent is infra-marginal and not visible from the upper surface, it is transversely 
oblong or triangular, and situated in several species in a rostrated development of the 
single inter-ambulacrum. 

The ambulacra are short and subpetaloid, and the zones are formed of simple, equal, 
non-conjugate pores, disposed in pairs,which are closely approximated at the summit, apart 
in the middle of the zone, and approximated at the ambitus, PI. LVII, fig. 2 h, c ; at 
the base they are feebly indicated by lines which converge around the mouth-opening. 

The tubercles, which are large for so small a test, are scrobiculated, those at the base 
are the largest, and the sm-face of the plates likewise is covered with minute granu- 
lations. 



FROM TPIE UPPER GREENSAND. 255 

The apical disc is nearly central, with four perforated ovarials and five small oculars, 
the spongy body extending into the middle of the disc. 

The mouth-opening is nearly central, always obliquely elongated. 

This genus belongs essentially to the Cretaceous formations. The Upper Greensand, 
Craie Chloritee, or Etage Cenomanien, has yielded C. trirjonopi/ffus, faba, rostratus, and 
orbicularis ; of these the first three are found both in the Anglo-Parisian and in the 
Pyrenean basins,, and the last up to the present time only in the Anglo-Parisian basin. 

In the White Chalk, or I'Etage Senonien are four species — C. avcllanus, sidcato-radiatus, 
tniiicatus, ?iw^ peltiformis, all of whicli are found in the Anglo-Parisian basin. 

The only specimen discovered in England is C. rostratus. 



Caratomus rostratus, Ayassiz, 1840, PI. LVII, fig. 2 a — e. 

Caratomus kosteatus, Agassiz. Catalogus Syst. Ectyp., p. 7, 1840. 

— — Besor. Monog. des Galerites, p. 38, pi. 5, figs. 1 — 4, 1842. 

— — Morris. Cat. of Brit. Foss., p. 49, 1843. 

— — Agassiz et Desor. Cat. Rais., p. 93, Modele No. 81, 1847. 

— — d'Orbigny. Prodrom., t. ii, p. 178, Stage 20e, 1847. 

— — Forbes. In Morris' Cat. of Brit. Foss., p. 73, 1854. 

— — (/'Or%Ky. Pal. Fran9aise, Ter. Cre'taces, pl.941,p. 367, 1855, 

Diagnosis. — Test thick, depressed, round, inclining to oblong, obtusely round before, 
and prolonged into a rostrum behind ; apical disc slightly excentral ; base convex, 
pulvinated, depressed near the, mouth, wdiich is small, oblique, and excentral; vent 
triangular, infra-rostral at the lower third of the height ; ambulacra narrow and obscured 
by large scrobiculated tubercles. 

Dimensions. — Antero-posterior diameter four tenths of an inch ; breadth three tenths 
of an inch ; height two tenths of an inch. 

Description. — This little Urchin was first figured and described by M. Desor in his 
beautiful Monograph on the Galerites and has since been figured by d'Orbigny in the 
' Paleontologie Eran9aise.' The shell is thick and depressed, longer than wide, very obtuse 
anteriorly, and ending in a prolonged rostrum posteriorly, which gives it a pyriform 
aspect. 

The ambulacra are narrow and scarcely visible, being obscured by large scrobiculated 
tubercles ; in order to expose the poriferous zones it is often necessary to treat the 
test with some dilute acid. I have never been fortunate enough to obtain so good a 
specimen as the one which my late esteemed friend Mr. Bone procured for his beautiful 



256 ECHIXOLAMPIDtE. 

drawings of tins species, and of which he has given details all magnified six diameters. The 
ambulacra are narrow and subpetaloid and the pores in the zones are small, equal, and 
non-conjugate. The surface of tlie test is covered with scrobiculated tubercles, which are 
large in proportion to the size of the shell ; these Avith the thickness of the test serve to 
obscure the details of its structure. 

The apical disc, which is likewise the vertex, is placed a little before the centre, and is 
composed of four perforated genital and five ocular plates, and the spongy body projects 
towards the middle of the disc. 

The large triangular vent is situated at the under side of the projecting rostrum, fig. 2 c\ 
d, e, and is so completely infra-marginal that the aperture cannot be seen from the upper 
surface. The great development of the intra-ambulacrum which produces the rostrum 
fomis one of the most marked characters of this species, fig. 2 c, and serves to distin- 
guish it from the congeners. 

The base is convex and pulvinate ; it is a little depressed near the middle, where the 
oblique mouth-opening is situated, fig. 2 c; the lines of zone-pores are here visible, and 
the scrobiculated tuljercles are even larger than on the upper surface. 

Affinities mid Dijfcrences. — This species resembles C. trirjonopygus, but is distinguished 
from it by its long recurved rostrum, fig. 2 c. The shell is likewise more inflated and the 
base more convex. 

LocnUiij and Stratigrapliical Position. — This species is found only in the Upper 
Greensand near Warminster, Wilts. In France it is likewise special to " I'Etage Ceno- 
manien," or the " Craie Chloritee," from whence it has been collected at Havre, 
Seine-Infcriem'e, at Fourras, Charente-Inferieure, and at Vaches-Noires, Calvados. 



Family 10 — Echinolampid^, Wright, 1856. 

Test thin, oval, oblong, elevated, or subdiscoidal ; ambulacral areas large, petaloidal -, 
poriferous zones wide, pores distant, united by sutures, and extending nearly to the 
margin. 

Mouth-opening small, subcentral ; peristome smTounded by five prominent lobes, and 
always by a well-developed pentaphylloid floscelle. 

Vent oval transversely and infra-marginal. 

Apical disc very small, excentral, and composed of four perforated genital and one 
imperforate plate, with five minute oculars wedged into the circumference of the disc. 

Plates of the upper surface covered with several rows of numerous small, closely set 
tuljercles encircled bv sunken areolas. 

A few species are now living in warm seas ; the greatest number are extinct, and 



FROM THE UPPER GREENSAND. 257 

found in the Oolitic, Cretaceous, and Tertiary rocks, where they form important leading 
fossils of the strata which they characterise. 

I include the following genera in this Family : 

EcHiNOLAMPAS, Gray. Echinanthus, Breynius. 

Pygurus, d'Orhigny. Conoclypus, Jyassiz. 

Faujasia, d'Orbiffny. Pygaulus, Jgassiz. 



Genus — Pygurus, tVOrbigny, 1S55. 

EcHiKANTHiTES, Leske, 1778. 

Clypeasteu (pars), Lamarck, 1801. 
EcHiNOLAMPAS (pars), Agassiz, 1836. 

Pygurus (pars), Agassiz, 1840. 

— cVOrhigny, 1855. 

— Besor, 1858. 

— Be Loriol, 1873. 

The genus Pygurus, as now limited, is composed of large, discoidal, or clypeiform 
Urchins, in wliich the test in general is more or less enlarged at the sides, and rostrated 
posteriorly ; its upper surface is usually depressed, and rarely elevated. The ambulacral 
areas and poriferous zones in the upper surface form petaloidal expansions, which have an 
elegant figure, being in general contracted at the border, enlarged in the middle, and 
attenuated at the apex. The anterior single area is narrower than the antero- and 
postero-lateral areas ; the summit is in general central, or slightly cxcentral, the inclina- 
tion being always forwards. The base is concave and much undulated, the wide basal 
interambulacra swell into prominent cushions, and the narrow ambulacra form contracted 
valleys between them. The mouth-opening is pentagonal, and always excentral ; the 
peristome is surrounded by five prominent lobes, with which five expanded ambulacral 
petals alternate ; in the poriferous zones near the mouth the pores are closely crowded in 
triple oblique ranks ; these perforated petals form an oral rosette or a penta-phylloid 
floscelle of considerable dimensions (PI. LVIII, fig. 1 c). 

The vent is infra-marginal ; it is in general oval, and surrounded by a distinct area, 
which occupies the rostrated portion of the single interambulacrum ; the long diameter of 
the opening in general corresponds with the longitudinal axis of the test, although it is 
sometimes transverse (PI. LVIII, fig. 1 c). 

The apical disc is very small, and occupies the summit ; it is composed of two pairs of 

33 



258 PYGURUS. 

narrow, perforated, and a single rudimentary imperforate, ovarial plate ; five minute 
ocular plates, are interposed between the ovarials (PI. LVIII, fig. 1 h). 

The small madreporiform body is attached to the surface of the right anterior ovarial, 
and forms thereon a spongy eminence, which extends over the other discal elements. 

The tubercles are very small on the upper surface, and larger at the base ; they are 
surrounded by sunken areolas, and have their summits perforated ; the intertubercular 
space is covered with close-set miliary granules (PI. LVIII, fig. 1 ^). 

The genus Fygurus first appears in the Lower Oolites, and its species are likewise 
found in the Inferior Oolite, Puller's Earth, Great Oolite, Cornbrash, Kelloway Rock, 
Coralline, and Portland Oolite. 

In the Cretaceous formations the species Fi/(/urus rostraius, P. GiUieroni, P. 
Buchii, characterise the Lower Neocomian or Valangian ; Pygurus Monfmolini and P. 
Salevcnsis are found in the Middle Neocomian ; Pygurus productus comes from the 
Urgonian ; Pygurus Eicordeanus from the Gault ; Pygurus Lampas from the Upper 
Greensand or Cenomanian. Of the eight Cretaceous species one is found in the English 
Upper Greensand, where it is so rare that I know only of two specimens, and one of 
these is preserved in the British Museum. 



Pygurus Lampas, Be la Beche, 1819, PI. LVIII, figs. \a — \h. 

Clypeaster oviformis, Lamarck. Anim. sans Vert^bres, t. iii, p. 15, 1816. 
EcHiNOLAMPAs Lampas, De la Beche. Geol. Trans., 2nd eer., p. 112, t. iii, fig. 3, 1819. 
Pygduus trilobus, Agassiz. Cat. Syst. Ecty., p. 5, 1840. 

— — Jffassh and Desor. Cat. rais., p. 103, Modele No. 39, 1847. 

— — d'Orbigny. Prodrome, t. ii, p. 178, Etage 20, 1847. 

— OVIFORMIS, d'Orbigny. Pal. Fran9aise, t. 91 9, torn, vii, p. 311, 1855. 

— Lampas, Desor. Synopsis Echinides foss., p. 311, 1858. 

Biagnosis. — Test high, very convex above and concave beneath, much longer than 
wide, largely rostrated, and abruptly truncated behind ; ambulacra lanceolate, poriferous 
zones subpetaloidal, apical disc and vertex excentral ; base very concave and much undu- 
lated ; mouth excentral ; peristome surrounded by a pentapetaloid floscelle of complicated 
structure ; interambulacrum much developed, recurved, and truncated ; vent transverse 
and infra-marginal. 

Bimensions. — This very I'are British Urchin was first noticed by my old esteemed friend 
Sir Henry De la Beche, E.R.S., who collected it from the Upper Greensand near Lyme 
Regis, and figured it in the ' Transactions of the Geological Society,' depositing the specimen 



FROM THE UPPER GREENSAND. 259 

in the British Museum. Sir Heury called it Lampas, from its i-esemblance to an ancient 
lamp when held with the base uppermost. Lamarck, 1816, described a Clypeaster as C. 
ovi/ormis, from the South Sea, collected by Peron and le Sueur, and referred " la variete 
que se trouve fossile dans les vignes aux environs du Mans" to the same species. Erom the 
angular character which the posterior half of the test exhibits Agassiz called it trilobus. 
D'Orbigny, finding that Lamarck had noticed the fossil species from Mans as a variety of 
C. oviformis, has given this name to the fossil, which is quite distinct from the living 
form. I have, therefore, followed my friend Professor Desor, and retained Sir Henry 
De la Beche's most appropriate name. 

The test is oval or oblong, obtusely rounded before, hollowed out on the sides, and 
prolonged into an abruptly truncated rostrum behind ; it is very convex, and inflated on 
the upper surface, its profile forming a regular curve, which is a little more depressed 
behind the vertex than before (fig. 1 a). The ambitus is very angular (fig. 1 a, b) in its 
posterior half, and the two lateral and one posterior lobe gives value to the name trilobus 
which was proposed for it. The single inter-ambulacrum is much prolonged, and on it 
two carinse are developed, which proceed from the apical disc to the sides of the 
truncated border (fig. 1 b, c), and impart a still more angular appearance to the test. 

The ambulacra are largely petaloid on the upper surface (fig. 1 b). They are 
contracted at the ambitus (fig. 1 d, e), and are again largely developed and petaloidal at 
the base (fig. 1 c). 

The poriferous zones are well developed and visible throughout in the petaloidal 
portion on the dorsum ; the pores in the external row are elongated, and in the internal 
row round ; at the ambitus they are remote and microscopic, and in the base they again 
become largely petaloidal, where they surround the mouth ; the petals here are distin- 
guished hy their elegant forms and complicated structure ; the pores are increased in 
number, and set in oblique pairs on the sides of the petals, and in the centre of each is a 
longitudinal enlargement like the stem of a leaf (fig. 1 c). This remarkable structure is 
shown magnified two diameters. 

The large plates on the upper surface have several rows of small tubercles, which 
become larger and less numerous at the base (fig. 1 (/) ; besides these a fine close-set 
granulation covers the surface of all the plates. 

The apical disc is very small, so that the lanceolate ambulacra meet close together at 
the vertex, which is slightly excentral ; there are four perforated genital plates, with a 
small spongy body in the centre (fig. 1 //). 

The vent is large, transversely oval, and opens near the border of the infra-marginal 
portion of the rostrum (fig. 1 c). 

Affinities and Differences. — This fine Urchin is distinguished from its congeners by its 
elevated upper surface, angular ambitus, prolonged rostrum and hollowed-out sides, by its 
rostral carinse, and the remarkable pentapetaloid arrangement of the pores around the 
peristome. 



260 SPATANGIDyE. 

Locality and Stratij^rapJdcal Position. — It was collected from the Upper Greensand 
near Lyme Regis, where it appears to be very rare, as I have seen only one 
other English example in addition to Sir Henry De la Beche's gift to the British 
Museum. In France it is found not unfrequently in the Micaceous Sandstone, I'etage 
Cenomanien of Mans, Sarthe, and in the Gres Calcarifere (Cenomauien), of Fouras, 
Charente-Inferieure. 



Family 11. — CLYPEASTERiDiE, WriffJit, 1856. (Not yet found in British Cretaceous 

strata.) 



Family 12. — Spatangid^, d'Orbiyny, 1853. 

The general outline of the urchins of this family is oval, oblong, or cordiform, and 
they satisfactorily exhibit the bilateral symmetry of the Echinidse. Tbe mouth is 
anterior, bilabiate, and edentulous. The anal opening is posterior and supramarginal, 
and closed by a complicated series of small periproctal plates. The arabulacral areas are 
united at the summit of the test. The anterior single ambulacrum has a different 
structure from the antero- and postero-lateral pau's, and is lodged in a depression 
of the test, which extends to the anterior border and forms the anteal sulcus ; the 
test is extremely thin, and covered with small perforated tubercles, which support 
hair-like spines ; besides these there are some larger crenulated and perforated tuljercles, 
which support large spines. There are two or four genital pores, which are some- 
times placed close together, but in other genera are apart. The eye-plates are five 
in number, and placed in a pentagonal form at the apices of the ambulacra around 
the genital plates. We observe on the surface of the test of some Spatangidse certain 
delicate lines called fascioles, having a smoother appearance than the tubercular sur- 
face of the test ; they are furrows which are strewed with microscopic tubercles 
destined to carry very delicate spines which, when seeu under the microscope, appear 
to have a structure similar to the Pedicellarise. The fascioles have a different dispo- 
sition in each genus, and afford a good generic character in giving definitions of the 
same ; when the fascicle surrounds the ambulacral petals like an undulating groove, 
as in Hemiaster, Schizaster, &c., it is said to be peripetalous ; when it surrounds the 
single ambulacrum, as in Jmpkidetus, it is internal ; when it extends along the sides, as 
in ScJiizaster, it is lateral ; when it encircles the circumference of the test, as in 
Pericosmtis, it is marginal; when it is limited to the base of the anal opening it is 



IIEMIASTER. 261 

subanal. We find sometimes in tlie same genus more fascioles than one; thus the 
subanal and peripetal are frequently associated together. 

This family contains many genera, none of which are found in rocks older than the 
Cretaceous formations ; the species increase in number in the Tertiary beds, and attain 
their greatest development in our present seas. In the Cretaceous rocks we find the 
extinct genera 

Hemiaster, Desor. Enallaster, d'Orbipii/. 

Epiaster, d' Orhigny. ' Heteraster, d'Ordigny. 

Micraster, d'Orbi(/mj. Echinospatagus, Brepiitis. 

The new genus Paleopneustes, Al. Agassiz, proposed for a species brought from 
Barbadoes by the Hassler expedition, appears to fiumish an interesting link between the 
EcHiNOCORiD^ and SpATANGioiE. In its general form it resembles Ecldnocorys 
vulgaris, its anteal sulcus is rudimentary, and it has structural affinities with the anterior 
single area of that Urchin. The other ambulacra are subpetaloidal ; and the peristome 
bilabiate with well-developed lips. 



Genus — Hemiaster, Desor, 1847. 

Urchins with a short, elevated, inflated, or cordiform test. The ambulacral summit 
in general excentral and posterior. The pairs of ambulacra petaloidal, unequal in length, 
and lodged in depressions of the surface ; poriferous zones large and equal in the same 
ambulacra, the pores elongated and placed close together. The single ambulacrum 
lodged in a long, shallow, anteal sulcus ; the poriferous zones are very narrow and com- 
posed of small round pores, sparsely disposed in oblique, widely separate, simple pairs. 

The fasciole single, peripetalous, and circumscribing the ambulacra. 

The apical disc small and compact, four perforated genital plates, and five very small 
oculars. 

Peristome bilabiate, very excentral, opening at the anterior fourth part of the base. 

Periprocte opening high up on the posterior border, which is in general flat, and 
obliquely truncated. 

Hemiaster differs from Micraster in having a single peripetalous fasciole and no anal 
fasciole ; the test likewise is in general shorter, more inflated, and the posterior pair of 
ambulacra are mucli shorter than the anterior pair. Hemiaster differs from Periaster in 
having only a peripetalous fasciole, the latter having both peripetalous and lateral 
fascioles. 



262 HEMIASTER. 



Hemiaster Morkisii, Forbes, 1S54. PI. LXI, fig. a — k. 

Spatangus pkunelia, Mantell. Geology of Sussex, pi. xvii, figs. 22, 23, 

1822. 
Hemiaster — Besor. (pars) Cat. raisonee, p. 122, 1847. 

EcHiNOSPATANGUS CORDIFOKMIS, Mantell (pars). Geol. Sussex, p. 108, 1822. 
Spatamgus complanatus, Mantell. Medals, p. 355. 

Hemiaster puxctatus, (VOrbigny. Pal. Franc. Ter. Cret., pi. 886, 1854. 

— MoRRisii, Forbes. Morris, Cat. Brit. Foss., 2nd ed., p. 81, 

1854. 

— — Woodward. Mem. Geol. Surv., decade 7, pi. ix, 1856. 

Diagnosis. — Test oval, polygonal, or cordiform, inflated, obtusely rounded before and 
obliquely truncated behind, sides nodulated; ambulacra straight, narrow, moderately 
depressed, anterior pair twice as long as posterior, anteal sulcus short, shallow, dorsal ; 
apical disc excentral backwards ; vertex near posterior border, which is flat and obliquely 
truncated ; periprocte oval, supra-marginal ; base convex, with a slight depression near the 
mouth, which is bilabiate and opens near the border; fasciole narrow, distinct, closely 
siu'TOundiug the petals. 

Dimensions. — Antero-posterior diameter one inch and six tenths ; breadth one inch 
and five tenths ; height one inch. 

Descripfion. — This Urchin has been long known to collectors of Cretaceous fossils by 
many incorrect names. I have now figured it with ample anatomical details for the first 
time, which for the future will make it impossible to mistake it for any other. 

The outline is oval, slightly polygonal, or inclining to a cordate shape ; the anteal sulcus 
is broad and obscure, and impresses shghtly the anterior border, which is obtusely rounded 
and sometimes flattened; the posterior border is obliquely and flatly truncated, and 
slopes at an angle of 70° ; sometimes this border becomes slightly concave in large shells, 
and it is conspicuously so in three specimens in my collection. 

The ambulacra! petals are small and moderately depressed, the anterior incline 
45° ; are nearly twice as long as the posterior pair (fig. 1 a) ; the poriferous zones are 
narrow, and the pores form oblique transverse slits in them ; the single area is about same 
length as the anterior, and is lodged in the anteal sulcus ; there are from twelve to fourteen 
pairs of pores in each zone, with a prominent granule between each of the pores forming 
a pair (fig. 1 «) ; the anteal sulcus widens out and disappears at the anterior border. 

The inter-ambulacral areas present a remarkable nodulated appearance in this species ; 
in each area there are two rows of these elevations ; those at the sides are seen in 
fig. 1 a, c ; in the front in fig, 1 e; and the back fig. 1 d; in fig. 1 /t the appearance 



FROM THE LOWER CHALK. 263 

these nodules present is admirably shown in three inter-ambulacral plates taken from the 
ambitus and magnified three diameters. 

The peripetalous fasciole is very well defined in this species ; it passes straight from 
point to point with scarcely any curvature, and forms a bold line among the numerous 
tubercles ; fig. 1 g shows this structure. 

The tubercles are small, very numerous, and set irregularly on the plates ; they are 
all perforated, and raised on bosses surrounded by well-defined areolas ; fig. 1 i shows 
the tubercles on the upper surface, and fig, 1 k those on the under surface, where the 
larger tubercles have the bosses crenulated ; besides the tubercles the entire surface of the 
plates is closely covered with miliary granules. 

The apical disc is small and excentral, the four genital plates are perforated, and the 
antero-lateral carries the spongy body (fig. 1 /) ; the five ocular plates are very small, as 
shown in fig. 1 f. 

The oval periprocte occupies the upper third of the oblique posterior border (fig. 1 «?), 
and the vertex is seen rising above it all, as shown in fig. 1 c, d). 

The base is convex transversely behind the mouth (fig, 1 b, c), and flat before that 
aperture. The basal portions of the ambulacral areas, especially the postero-lateral pair, 
which first descend backwards towards the ambitus, bend round the border forming an 
obtuse angle there, and make a sinuous coiu'se to the mouth. The anterior pair and the 
single area have a more direct course ; the basal portions of the postero-laterals are 
destitute of tubercles and granules (fig. 1 b). 

The mouth-opening is situated at the anterior fourth of the base ; it is transversely 
arched and bilabiate, the lower lip being the most prominent, and the peristome is 
surrounded by a narrow calcareous band. 

The tubercles on the basal portion of the inter-ambulacrum have a remarkable 
arrangement. They form a series of curved rows that radiate from a central nodule 
near the posterior border and from a kind of fan-shaped tubercular sculpture between the 
two smooth winding paths formed by the sinuous ambulacra (fig. b). The tubercles on 
the other portions of the inter-ambulacra have a much less regular arrangement. 

Affinities caul Differences. — This species resembles //. prunella, Desor, with which it 
has been confounded ; it diff'ers from that species, however, in being much larger, less 
globular and inflated, having the posterior border obliquely truncated, the dorsum much 
more inclined, and having the tubercles smaller and more numerous, and the inter- 
ambulacra nodulated around the sides. 

Locality and Stratit/rapJncal Position. — This species is found only in the Grey 
Chalk near Folkestone, the Lower Chalk at Hamsey, Sussex, and in the Grey Chalk of 
Ventnor, Isle of Wight. 



264 HEMIASTER. 



Hemiaster Bailti, Forbes. PL LX, fig. 2. 

ECHINOSPATANGUS, Mantel!. Geology of Susses, p. SG, 1822. 

IIOLASTEK ABGILLACEUS, Morris (pars.), Catalogue Brit. Foss., 1st ed., p. 54, 1843. 
Hemiaster Bailyi, Forbes. Morris, Catalogue, 2nd ed., p. 81, 1854. 

— Woodward. Mem. Geol. Surv., decade v, 1856. 

The specimen figured in this plate belongs to the Museum of the Royal School of Mines, 
and is so much crushed and its characters defaced that I am unable to give a correct 
diagnosis of the species, and now figure it as the authentic example of my late friend's 
species. The outline figiu-e and general contour of the test resemble Eddnospatagus 
Murchisonianus. " The peripetalous fasciole is narrow, distinct, and simple in contour, 
passing from end to end of the ambulacral petals and only slightly contracted at the 
sides. The surface of the Echinidae from the Gault is in general rough with nodular 
concretions of iron pyrites formed upon the tubercles. So many of the Blackdown 
fossils are identical with species of the Folkestone Gault that we have felt considerable 
hesitation in admitting as specific a character which may by any possibility be due to the 
mineral condition of the specimens." — Woodward. 

Localiiy and Stratif/rapldcal Position. — Collected from the Gault at Folkestone; 
the type-specimen I have figured is contained in the Museum of the Royal School of 
Mines. 



Hemiaster asterias, Forbes. PI. LX, fig. 3. 

Hemiaster asterias, Forbes. In Morris, Catalogue, 2nd ed., p. 81, 1854. 
— — Woodward, Mem. Geol. Surv., decade v, 1856. 

The type-specimen I have figured is not sufficiently well preserved to enable me to 
form a diagnosis of the species. The vertex appears to have been more prominent and 
removed more posteriorly than in //. Bailp, and the dorsal ambidacra are likewise 
rough and narrower in proportion than in that species. 

Locality and StratiyrapUcal Position. — Collected from the Gault at Folkestone, 
where it is rare. The type-specimen I have figured belongs to the Museum of the Royal 
School of Mines, Jermyn Street. 



THE 



PALJIONTOGRAPHICAL SOCIETY. 



INSTITUTED MDCCCXLVII. 



VOLUME EOE 1878. 




LONDON: 

MDCCOLXXTIII. 



MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODERMATA 



TEOM 



THE CRETACEOUS FORMATIONS. 



THOMAS WRIGHT, M.D., F.R.S. Edin., F.G.S., 

VICE-PRESIDENT OF THE PAL«ONTOGBAPHICAL SOCIETY; CORRESl'ONDING MEMBER OF THE ROTAL SOCIETY OE SCIENCES 

OF LIEGE; THE SOCIETY OF NATURAL SCIENCES OP NEUCHATEL; VICE-PRESIDENT OF THE COTTESWOLD 

naturalists' field CLUB; CONSULTING SURGEON TO THE CHELTENHAM HOSPITAL; 

AND MEDICAL OFFICER OF HEALTH TO THE URBAN SANITARY DISTRICTS 

OF CHELTENHAM, CHAELTON-KINGS, AND LECKHAMPTON. 



VOLUME FIRST. 

PART EIGHTH. 
ON THE SPATANGID^ AND ECHINOCORID^. 

Pages 265—300 ; Plates LXIIa, LXIII— LXIX. 



LONDON; 

PRINTED FOR THE PAL^EONTOGRAPHICAL SOCIETY. 

1878. 



PRINTED BY 
J. E. ADLABD, BARTHOLOMEW CLOSE. 



EPIASTER. 265 



Genus — Eptaster, d' Orbi^ny, 1S5S. 
Spatangus (pars), Auctorum, Micrasteb (pars), Agassis. 

Form oblong ; test more or less elevated, often cordiform. 

Antero- and postero-lateral pairs of ambulacra petaloidal and lodged in depressions 
of the test; the anterior are longer and more developed than the posterior pair. 
Poriferous zones equal in each ambulacra, composed of elongated pores shorter in the 
internal than in the external rows. 

The single ambulacrum, lodged in a well-defined anteal sulcus, is composed of pores 
different from those of the antero- and postero-lateral pairs, as they are mostly round 
and disposed in pairs set widely apart. 

The apical disc is composed of four perforated genital and five ocular plates. 

Peristome near the anterior border and strongly bilabiate ; the inferior lip thick and 
prominent. 

Periprocte round or oval, situated at the posterior border, often opening in a 

distinct area. 

No fascioles. 

Tubercles well spaced out, unequal in size, crenulated, and often scrobiculated ; inter- 
tubercular area covered with granules. 

The Epiasters have been long confused with the Micrasters, which they resemble 
much, but differ from that genus in the absence of all fascioles. They are distinguished 
from Echinospatagus by their ambulacra, which are in the form of enclosed petals, 
by their poriferous zones, which are equal, and by their peristome, which is markedly 
bilabiate. 



Epiastek De Loriolii, JFriffht, nov. sp. PI. LIX, figs. 1, a—ff. 

MiCKASTER LACCNOSUS, Morris. Catalogue of British Fossils, Isted., p. 55, 1843. 
Hemiaster bucardium, Woodward. Mem. Geol. Surv., decade v, pi. is, notes, 1856. 

Diagnosis. — Test large, cordiform, declining anteriorly, elevated posteriorly ; anteal 
sulcus deep, grooving the border ; ambulacra much depressed. Antero-laterals curved 
slightly forwards and outwards, and inclined at 45° ; postero-laterals shorter, curved 

34 



266 EPI ASTER 

backwards and inwards, and inclined at 30° ; posterior border obliquely truncated ; vent 
large, oval, supra-marginal ; base convex ; mouth-opening in the anterior fourth ; peri- 
stome bilateral. 

Dimensions. — Length, antero-posterior diameter two inches and five tenths ; breadth, 
two inches and five tenths ; height, one inch and five tenths. 

Description. — This fine large Epiaster has been long known to geologists as a fossil 
from the Upper Greensand of Wiltshire, as I have detected specimens in difierent 
collections made many years ago. It was erroneously identified with Parkinson's 
Spafanpus lacunosus, which is a Maltese specimen, and was entered in the first edition of 
Morris' Catalogue as Micraster lacunosus. It was omitted from the second edition of 
that work, and described by Dr. S. P. Woodward as Hemiaster bucardium, from his 
belief that it agreed with Goldfuss' figure. 

The test is large and cordiform in middle growth, and round and tumid with age, 
when its width and length are about equal. The vertex is at a point between the 
terminal portions of the postero-lateral ambulacra, from whence its horizontal profile 
slopes gently towards the anterior border and backwards to the abruptly truncated 
posterior border. 

The anteal sulcus is deep and narrow, with nearly vertical walls ; it grooves deeply 
the anterior border, fig. 1 a, and extends from the disc to the mouth, fig. 1 e. 

The pores are small, biserial, closely set together, and limited to the upper half of the 
area, with a prominent granule between the two pores forming a pair. 

The ambulacra are much depressed, circumscribed, and unequal in length and 
inchnation ; the antero-lateral are one third longer than the postero-lateral pair. 

The poriferous zones are wide, of unequal length, and formed of transversely elon- 
gated pores, those in the posterior zone of the antero-lateral pair are the longest and there 
the pores are widest apart. 

There is no true peripetalous fascicle, and the naked line which Mr. Bone mistook 
for this structure and figured as such appears to have been produced by friction on the 
sutures of the large inter-ambulacral plates forming the peripetalous area added to a 
certain local baldness at the terminal portions of the depressed ambulacra, so that 
referring to Plate LIX the student must please delete the peripetalous naked line in 
fig. 1 a, c, d, e, f ; in all other respects the various figures given on this plate are 
admirable delineations of the form and structure of this fine Epiaster. 

The apical disc is central ; it has four perforated ovarial plates, a very small spongy 
body, and five oculars with distinct orbits. 

The numerous small tubercles are arranged in rows in quincuncial order on the 
plates and the mterspaces are covered besides with abundant granulations. Fig. 1/ 
represents three inter-ambulacral plates, the terminal portion of an ambulacrum, with 
its poriferous zones, magnified three diameters in order to illustrate this portion of the 
anatomy of the test. 



FROM THE WHITE CHALK. 



267 



Affinities and Differences. — The wide test, deep ambulacra, and inclined upper surface 
distinguish this Urchin from all its congeners ; and likewise from the Micrasters with 
which others have been often confounded. 

I dedicate this fine species to my esteemed friend M. De Loriol, the learned author of 
the ' fichinologie Helvetique/ whose assiduous studies in Palaeontology have borne such 
ample fruits. 

Locality and Stratigrapldcal Position. This species has been collected from the 
Upper Greensand, near Warminster and Devizes, Wilts. 



Epiaster gibbus, Lamarck, 1816. PI. LXIH, fig. 1, a — k. 

Spatangus gibbus, 



— COB-ANGUINUM, 

— GIBBUS, 



Lamarck. Animaux sans Vertebres, t. iii, 

p. 32, 1816. 
Deslo7tff champs. Enc. Method., p. 689, 

pi. 156, figs. 4— 6, 1824. 
Gold/uss. Petr. Germanise, tab. xlviii, fig. 4, 

p. 155, 1824. 
Defrance. Diet. Sc. Nat., t. 1, p. 94, 1827. 
Woodward. Geol. of Norfolk, pi. v, fig. 8, 

1833. 
De Blainville. Manuel d'Actin., pp. 203, 653, 

1834. 
Grateloup. Oursins Foss. (Dax), p. 71, 

1836. 
Desmoulins. Etudes sur les Echinides, p. 402, 

1837. 
Edwards. Anim. sans Verteb., t. iii, p. 331, 

1840. 
Agassiz. Catal. Syst., p. 129, 1847. 
Hebert. Etudes sur les Terr. Cretaces ; Mem. 

Soc. Geol. France, 2e ser., t. v, pi. xxix, 

fig. 16, 1854. 
Desor. Synopsis Echid. Foss., p. 365, 1858. 
Forbes (pars). Mem. Geol. Surv., dec. iii, 

pi. X, 1850. 
Forbes. In Dixon's Geol. of Sussex, p. 342, 

pi. xxiv, figs. 5, 6, 1850. 
COE-ANGUINUM var. GIBBUS, Morris. Brit. Foss., 2nd ed., p. 83, 1854. 

— d Orbigmj (pars). Paleont. Fran9aise Terr. 

Cret., t. vi, p. 207, 1855. 



MiCKASTER CORDATUS, 



— GIBBUS, 

— COR-ANGUINUM, 

— GIBBUS, 



Diagnosis. — Test cordiform, very high, and almost conical ; sides convex and 
carinated. Ambulacra slightly depressed ; anteal sulcus shallow above and grooving the 
anterior border ; posterior margin acuminated and truncated obliquely inwards. Vent 



268 EPIASTER 

round, supra-marginal ; base slightly convex transversely ; mouth-opening very near 
the border, bilabiate, with prominent under lip ; apical disc nearly central, and placed 
before the vertex. 

Dimensions. — Height, 1-j^ inch ; length, 2^^ inch. 

Description. — There has been so much difference of opinion about this Urchin that I 
have given full details of the anatomy of its test in PI. LXIII. 

Lamarck, yvho first described it, has the following diagnosis : — " Sp. cordato- 
abbreviatus, convexus, subgibbosus, antice retusus ; vertice elato ; ambulacris quinis, 
duplicato-biporosis ; ano ovato ;" and refers to the figure in the ' Encyclopedic 
Methodique,' pi. 156, figs. 4 — 6, as the type of the form. Goldfuss gave in his 
' Petrefacta ' excellent figures and an accurate description. Woodward sketched a fair 
outline of it in his ' Geology of Norfolk,' but mistook it for the common Chalk species 
Micraster cor-anguinum. Desmoulins, De Blainville, Deshayes, Grateloup, and Desor, 
all retained the species as established by Lamarck. My late esteemed colleague. 
Professor E. Forbes, upheld Woodward's mistake, and mentioned it as a variety of 
Micraster cor-anguinum in the 'Memoirs of the Geological Survey,' Decade III, PI. 10, 
whilst oddly enough he had previously described it correctly in his account of the 
Echinodermata in Dixon's ' Geology of Sussex.' D'Orbigny in his ' Paleontologie 
Frangaise ' groups M. gibbus with M. cor-anguinum, and perpetuates the old confusion 
I have pointed out. 

If we admit that the structure and disposition of a fasciole oxfascioles form characters 
of sufficient importance for the establishment of generic groups among the Sjjafa7igidcB, 
then, indeed, the Urchin under consideration is not only specifically but generically 
distinct from Micraster cor-anguinum, for, whereas all true Micrasters have a subanal 
fasciole, forming a ring placed around the base of the posterior border, one half of 
which embraces the border, the other half the base, the Urchin before us has no 
fasciole whatever ; and this anatomical fact has been altogether overlooked both by Forbes 
and d'Orbigny, otherwise they would not have confused ^z'Wws with cor-anguinum. 

The build of this Urchin differs from M. cor-anguinum in having a flattened base, an 
angular ambitus, and a pyramidal upper surface, with steeply-inclined sides, the anterior 
portion sloping at an angle of from 40° to 50°, the posterior from 25° to 30°, and the 
lateral sides 35°. In half a dozen good typical specimens these measurements represent 
a fair average. PI. LXllI, fig. 1, c, d, e. 

The ambulacral areas are narrow, and their petaloidal portions not much depressed, 
fig. 1 a, c, d, e ; the antero-lateral being one third longer than the postero-lateral pair. 
The poriferous zones of the petals consist of a pair of holes, the inner being rounder 
than those in the outer line, and they are connected by a slight depression in the plates, 
fig. 1 g. Beyond the petals the zones diverge ; and in the anterior pair I have traced 
the holes to the ambitus, in the posterior pair they have disappeared. The anteal sulcus 
is feebly marked, and the single petal shorter than the anterior pair ; in the petaloid 



FROM THE WHITE CHALK. 269 

section it contains about 20 pairs of holes in each zone, and in the non-petaloidal portion 
of this area the small pairs of pores can be distinctly traced to the ambitus and onward 
to the mouth-opening, fig. 1 e, h. The ambulacral plates in the petaloidal portions of 
the areas are elongated and flat in the single area, and short, convex, and tumid in the 
antero- and postero-lateral pairs. There are several miliary granules on the plates in the 
single arc and only solitary granules on the convex surface of those in the pairs. 

The inter-ambulacral areas are formed of very large plates (fig. 1 a, c, d, e), which 
on the upper surface have a conspicuous mesial suture in each of the areas. All the 
plates are covered with several horizontal rows of tubercles, arranged in a quincuncial 
manner, fig. 1 g, on their surface, and the inter-areolar space on the same is profusely 
covered with microscopic granules ; fig. 1 g exhibits three of the inter-ambulacral and a 
portion of the petaloid and non-petaloid portions of the ambulacral plates, magnified 
three diameters ; the arrangement of the tubercles and granules is likewise well delineated 
in this beautiful drawing. The tubercles are raised on bosses encircled by sunken areolas, 
each of which is surrounded by a circlet of microscopic granules, so that the surface 
of the test in a well-preserved specimen, such as the type I have figured, is highly 
ornamented. 

The posterior border is a very limited space, and is truncated obliquely downwards 
and inwards; in its upper portion the vent is situated (fig. 1 d). The periprocte is large, 
circular, and supra-marginal, and its position in relation to the base is very well shown 
in fig. 1 c and fig. 1 d. 

The apical disc is small in proportion to the size of the shell. It consists of four 
perforated ovarials and five small, heart-shaped eye-plates ; the antero -lateral ovarial 
is much larger than the others, and extends obliquely into the centre of the disc, with 
the spongy body covering its surface as in fig. 1 a, where the relation of the disc to the 
petaloid ambulacra is shown, and in fig. 1 /, where the disc is drawn magnified eight 
diameters. 

The base is nearly flat, and most accurately delineated in fig. 1 b. The course of 
the basal portions of the postero-lateral ambulacra are observed dividing the base 
into a central and lateral regions ; the central extends from the lower labial prolongation 
backwards becoming merged in the posterior border, and is closely covered with 
tubercles, close-set and arranged with great regularity in this space : the lateral regions 
extending to the sides and anterior border have fewer tubercles, which are larger in size, 
but more sparse in their distribution than those which occupy the central shield. I have 
given a figure of the basal tubercles in fig. 1 h, showing the boss with its areola and 
circle of granules, and the perforated tubercle raised on the summit of the radiated 
bossal elevation. The enlargement is eight times, so that the comparative magnitude 
of the tubercles on the upper and under surfaces of the test of this species may be fairly 
estimated by comparing fig. 1 i with 1 h, and the whole in relation to the test in 
figs. 1 a and h. 



270 MICRASTER 

The mouth-opening is found very near the anterior border, figs. 1 h, c, and e. It is 
largely and transversely oblong, and the lower lip is thick and much prolonged. 

Affinities and Differences. — This Urchin resembles some forms of Micraster cor- 
anffuinum, and has long been considered by many a variety of that common Chalk species. 
An attentive study of the anatomy of their tests will soon disclose their affinities and 
difierences, which have already been pointed out in the introductory part of the descrip- 
tion, and to which I refer the reader. 

Locality and Stratigraphical Position. — The most typical examples of this species are 
found in the Upper Chalk at Harford Bridge, near Norwich, and from the Upper Chalk 
of Sussex, where it is very rare. The large specimen figured in ' Dixon's Geology of 
Sussex ' is a broad and abnormal form of the species, and is the type of my late 
colleague's description in the text of that work. 

Since this article was in type my friend Mons. de Loriol has called my attention to 
and given me a copy of a memoir by Dr. Clemens Schliitter (' Verb. d. Nat. Ver. 
Jahrg.,' xxvi, Folge 3, Bd. vi), "Fossilen Echinodermen des nordlichen Deutschlands," 
in which the author has published good figures and an accurate description of Epiaster 
gibhus. 



Genus — Micraster, Agassis, 1S36. 

Spatangus, pars, Auctorum. 
MiCEASTER, pars, Agassiz. 
Micraster, cFOrbigny. 
Micraster, Be Loriol. 

Body oval, oblong, more or less inflated ; test cordiform, thin, and fragile. 

Ambulacral pairs petaloidal, closed at their extremities, the anterior exceeding in 
length the posterior pair. 

Poriferous zones equal in each ambulacra. 

Holes oval or oblong, conjugated by transverse depressions. 

Anterior or single ambulacrum lodged in a wide, shallow, anteal sulcus, which 
deeply indents the border of the test. 

Pores small and round, and set obliquely in uniform pairs more or less widely apart, 
the distance of one pair from another increasing from the disc to the mouth. 

Apical disc small, central, solid, composed of four perforated ovarial and five perfo- 
rated ocular plates. 

Madreporiform body small, located in the middle of the disc. 

Mouth-opening transverse near the border ; peristome bilabiate, with a prominent 
projecting under lip. Base flat or slightly convex, covered with large, regularly arranged, 
well-developed tubercles. 



PROM THE WHITE CHALK. 271 

Posterior border narrow, obliquely truncated downwards and inwards, and slightly 
concave transversely. 

Vent located in the upper part of the border under a ridge-like projection of the 
dorsal surface. 

Periprocte oval and widely patent. 

Fasciole sub-anal, forming a ring around the posterior extremity ; embracing half 
of the upper and half of the lower part of the border. 

Tubercles perforated sparsely, distributed on the upper surface ; larger and placed 
closer together below. All are raised on bosses with crenulated summits. 

Spines small, needle-shaped, straight or bent, and enlarged and crenulated at the 
base. 

Micraster differs from Epiaster in possessing a well-defined sub-anal fasciole, and 
from Hemiaster and Periaster by the absence of a peripetalous fasciole. 

Micraster forms a leading genus of fossil Urchins, and well characterises the upper 
beds of the Cretaceous formation in the Anglo-Parisian, Pyreuean, and Mediterranean 
basins of Europe. 



Micraster cor-anguinum, Kleiti, sp., 1734. PL LXII, figs. 1 a — /, 3, 5 (not fig. 4), 

Brontia vel Ombeia, Plot. Nat. Hist. Oxfordshire, p. 91, pi. ii, iig. 11, 

1677. 
EcHiNiTES PESTER BADios, Lister. De Lapidibus Turbinatis, p. 224, fig. 28, 

t. vii, 1678. 
EcHiNiTES COKDATDS vuLGAEis, Llhwyd. Lithophylac. Britannici Iconograph, p. 47, 

Num. 964—967, fig. 964, 1699. 
EcHiNOSPATAGUS coKDiFOKMis, Breynius. Schediasma de Echiuis, p. 62, t. v, figs. 

5,6, 1732. 
Spatangus cor-anguinum, Klein. Naturalis Dispositio Echinodermatum, p. 28, 

t.xxiii, figs. A — D, 1734. 

— — Klein. Ordre Nat. des Oursins de Mer ; ed. Gall., 

p. 100, pi. xii, figs. E, F, pi. xiii, fig. c, 1754. 

— — ■ Leske. Addit. ad Kleinii Disposit. Echinid., p. 221. 

pi. xxiii, figs. A — D, pi. xxiii* c, and pi. xlv,fig. 12, 

1778. 
Echinus cor-angcinum, Gmelin. Systema Naturae, p. 3195, No. 91, 1799. 

Spatangus cor-mauincm, Parkinson. Organic Remains, vol. iii, p. 28, pi. iii, 

fig. 11, 1811. 

— COR-ANGUINUM, Lamarck. Anim. sans Vert., t. iii, p. 32, 1816. 

— PUNCTATUS, Lamarck. Ibid. 

— COR-ANGUINUM, Deslongchamps. Encyl. Method., t. ii, p. 63, 1824. 

— PUNCTATUS, Deslongchamps. Ibid. 

— COR-ANGUINUM, Befrance. Diet. Sc. Nat., p. 93, t. I, 1827. 

— PUNCTATUS, Befrance. Ibid. 



272 



MICRASTER 



PUNCTATUS, 
COR-ANGUINUM, 



PUNCTATUS, 

• — COR-ANGUINUM, 

PUNCTATUS, 

- COR-ANGUINTTM, 

MicKASTER cor-anguinum:, 



Spatangus COR-ANGUINUM, Goldfuss. Petrefacta Germaniae, vol. i, p. 157, 

pi. xlviii, fig. 6, 1829. 

— — De Blainville. Diet. Sc. Nat., t. xl, p. 135, 1830. 

De Blainville. Ibid. 
Agassiz. Prodrom., Mem. Sc. Nat. Neuchatel, t. i, 

p. 184, 1835. 
Besmoulins. fitudes sur les Echinides,p. 402, 1837. 
Desmoulins. IbiJ. 

Agassi:. Catal. Syst. Ectyp. foss., p. 2, 18-40. 
Dujardin. In Lamk. Anim. sans Vert., 2ud ed., t. iii, 

p. 328, 18-40. 
Dujardin. Ibid. 
Geinits. Charakteristik. Petref. Sachs-bohm. Kreide- 

gebirges, p. 91,1842. 
— Morris. Catalogue of British Fossils, p. 54, 1843. 

— — Agassiz et Desor. Catal. rais. des Ech., Ann. Sc. 

Nat., 3e ser., t. vii, p. 23, 1847. 

— — d'Orbigny. Prodrome Pal. Strat., t. ii, p. 269, 1850. 

— — Sorignet. Oursins foss. de I'Eure, p. 59, 1850. 

— — Forbes. Mem. Geol. Surv., decade iii, pi. x, 1850. 

— — Bronn. Letbsea geognost., Kreidegebirge, p. 200, 

1852. 

— — d'Orbigny. Paleontologie Fran9aise, Terr, cretace, t. vi, 

p. 207, pl. 867 (pars), 1852. 

— — Forbes. Morris, Catal. Brit. Fossils, 2nd ed., p. 83, 

1854. 

— — Eebert. Tabl. Foss. de la Craie de Meudon, Mem. 

Soc. Geol. de France, 2e serie, t. v, pl. xxix, 
fig. 15, 1854. 

— — Desor. Synopsis des Echinides fossiles, p. 364, 1858. 

— — Cotteau. Ecliinides de la Sarthe, pl. Iv, figs. 5 — 10, 

p. 326, 1860. 

Diagnosis. — Test cordiform, length and width nearly equal. Upper surface more or 
less inflated in difi^erent specimens ; enlarged and sinuous before, contracted and tapering 
behind ; the greatest diameter at the anterior third. Upper surface convex ; the anterior 
half declining obliquely from the disc to the anteal sulcus, and the posterior half 
forming a curved carinal ridge from the disc to the anal area ; posterior border flat, 
scooped out, and inclined inwards ; vent above opening under the rostrated carina. 
Under surface convex ; anteal sulcus equally hollowed throughout, from the disc to the 
mouth ; petaloid ambulacra unequal in length and slightly depressed ; mouth-opening 
near the border, with a very stout under lip. 

Dimensions. — Height, \\ inch ; length, 2^^ inches ; width, 2^ inches. 

Description. — This common Chalk Urchin has been long known to naturalists, and its 
flint moulds, collected from the Chiltern downs, were first figured by Plot in his ' History 
of Oxfordshire,' then by Lister and Llhwyd, and its test by Breynius, Klein, Van Phelsum, 



FROM THE WHITE CHALK. 273 

Leske and others. It presents a great many forms which have been considered distinct 
species by some, but only as varieties by others. The specimen I have selected for 
figuring and description is a capital type of the species in the highest state of preserva- 
tion, and the anatomy of the test has been carefully displayed in a series of figures in 
my late lamented friend Mr. C. R. Bone's best manner. 

The test is cordiform, and its width and length are nearly equal ; it is enlarged before 
and contracted behind, and its greatest transverse diameter is at the junction of the 
anterior with the middle third ; the upper surface is inflated ; from the disc to the anterior 
border it is obliquely depressed, fig. 1 c, and from the disc to the posterior border it 
describes a curved line which forms the summit of a carinal ridge extending to the vent 
and forming a rostrated process at the upper border of the periprocte ; the sides are much 
inflated, fig. 1 a, and the posterior border is flat, obliquely truncated downwards and 
inwards, and with the rostrated carina forms an excavation which imparts a specific 
character to the species, which is well delineated in fig. 1 c. 

The pairs of petaloid ambulacra are of unequal length, the anterior pair being the 
largest ; they are not much depressed and very slightly flexed ; the poriferous zones are 
narrow, not rounded at their extremity, and present certain characters which prevail 
throughout the various forms this species exhibits. 

The ambulacral plates are invariably tumid, rugose, and separated by a strongly 
marked suture, fig. 1 h, magnified four diameters ; whilst the general suture running down 
the centre of the ambulacral area is deeply depressed and grooved like fig. \ a ; the ridge 
separating each poriferous groove is also tumid and studded with a single tow of five or 
six small close-set tubercles, fig. 1 h. 

The single anterior ambulacrum is feebly petaloid in its upper part ; its pores are set 
much closer together than those in the pairs, and in many specimens the grooves 
connecting the pores are obsolete ; the pores of the inner row in the lateral ambulacra is 
rounder than those of the outer row, which are slightly elongated, fig. 1 li ; the non- 
petaloid portion of this area is more fully developed than in the corresponding portion 
of the others ; fig. 1 i shows the anterior ambulacrum. It is lanceolate, the plates are 
wide and irregular, each having a pair of small holes with tubercles placed between them. 
The inter-ambulacral areas are formed of large plates eight to ten in each column 
according to the age of specimen. They attain a greater development at the base, the 
postero-lateral pair forming the largest portion of the region, fig. 1 ^ ; the antero-lateral 
pair forming the anterior border, fig. \ a, e ; the carinal ridge, the anal area, the central 
shield of the base, with its circular subanal fascicle, and highly ornamented tubercular 
surface, are all formed by the single posterior area, fig. 1 b, c, d. 

The surface of the inter-ambulacral plates is covered with highly developed tubercles 
on the sides and upper surface ; each plate has four or five horizontal rows of them more 
or less regularly arranged as shown in fig. 1 /, where two of these plates are drawn 
magnified four diameters. 

35 



274 MICRASTER 

The plates in the ambulacral areas likewise support tubercles, but they are smaller 
and more sparsely distributed than in the inter-ambulacra ; the relative magnitudes of 
the tubercles in the two areas is shown in fig. 1 /, where they are both drawn to a scale 
of four diameters. The tubercles on the sides and upper surface consist of a perforated 
tubercle, placed upon a crenulated boss, and surrounded by a smooth areolar space, not 
scrobiculated on the upper surface, but very distinctly so at the base. They become 
much more numerous around the ambitus, and increase in size on the basal plates of the 
postero- lateral inter-ambulacral areas, fig. 1 b. On the triangular central space extending 
from the fasciole to the under lip, the tubercles are arranged in well-fonned rows that radiate 
forwards and outwards from a central tubercle and fill the entire space with close-set, 
regularly arranged tubercles, as shown in fig. 1 b ; the structure of the tubercles is very 
well delineated in the enlarged drawing of the same, made from a portion of the base where 
each areolar space is seen to be surrounded by a circle of granules and the intermediate 
portion filled in with the same. 

The tubercles supported small, needle-shaped spines, some of which are preserved on 
one of our specimens ; of these spines a few are slightly bent near the base, fig. 5 ; all are 
marked by fine longitudinal ridges, fig. 3 (destitute of spiral ornaments), which disappear 
towards the apex ; at the acetabulum a crenulated ring is visible. The minute spines 
with distinct ridges, which extend from base to apex, and which are traversed by a series 
of spiral depressions, fig. 4, occasionally found .in the beds containing M. cor-anguinum, 
belong to Echinothuria fioris and not to M. cor-anguinum. 

The apical disc is small and excentral, and composed of four perforated ovarial plates, 
the right antero-lateral being much the lai'gest and extending into the middle of the disc ; 
it is covered with the madreporiform body. The five ocular plates are wedged into the 
angular spaces left by the ovarials ; the discal elements being firmly soldered together, this 
portion of the test is nearly always well preserved. 

The posterior border is flat, abruptly truncated, and obliquely inclined downwards 
and forwards. The vent occupies the upper part of this region, and opens immediately 
under the rostrated carina. A few small tubercles are sparsely disposed below the 
vent and the lower part of the space is smooth, the fasciole encircles the angle, one 
half passing above, the other half below the basal angle. It is well seen in most 
specimens, and I have given a drawing of it in fig. 1 k, where it is seen passing as a 
finely granulated band between the tubercles on the plates. 

The mouth is placed very near the border, at the inferior termination of the deeply 
impressed anterior ambulacrum. It varies in position slightly in different specimens. 
The lower lip is thick and strong, and varies in tbe amount of projection, fig. 1 b and e. 

Affinities and Differences. — This species, so long known and so often described, has 
nevertheless been the subject of much confusion. The older authors, as Lister and 
Llhwyd, appear to have been acquainted with its moulds in fiint. Breynius and Klein 
studied its test, and the latter described it in 1734 under the name Spatangus cor-anguinum. 



FROM THE WHITE CHALK. 275 

His figures are very poor, and the varieties which he has united under the name appear to 
comprise forms which do not properly belong to the type. Goldfuss was the first who, in 
1829, gave an exact representation of the test from the able and accurate crayon of Herr 
Hohe. He separated it from his Spatangus cor-testudinarium, with which it had been 
united ; but the authors who followed Goldfuss have forgotten the distinction pointed out by 
him ; thus Agassiz and Desor in 1847 reunited these two species, and considered Micraster 
cor-testudinarium only as a large variety ol Micraster cor-anguinum.. Forbes in 1850, and 
d'Orbigny in 1853, increased the confusion, for by them nearly all the species of the 
White Chalk were referred to one and the same type, and Micraster gihbus, rostratus, 
cordatus, cor-testudinarium, latus, armatus, brevis, &c., successively established by different 
authors, were only admitted as simple varieties of Micraster cor-anguinum. 

Professor Hebert after a careful study and comparison of the species of Micraster 
reunited by Forbes and d'Orbigny, arrived at an opposite determination ; not only did 
he admit the vsW^xiy oi Micraster cor-testudinarium, gibbus, and brevis, \)Wi\\Q determined 
two other species. The structure of the ambulacral plates is the principal character 
upon which M. Hebert founds the description of his species. 

In his ' Synopsis des Echinides Fossiles,' published since Professor Hebert's memoir,^ 
M. Desor persists in uniting Micraster cor-testudinarium to M. cor-anguinum, and admits 
under reserve M. Brongniarti, Heb., and 31. Desori, Heb., proposed therein with such 
diverse opinions about the true characters pf this old fossil. When M. Cotteau was about to 
describe the species in his classical work on the ' Echinides du departement de la Sarthe,' 
he determined to study the species anew, and for this purpose collected all the necessary 
documents for reference and numerous specimens for comparison, and says, " Without 
adopting entirely the conclusions of M. Hebert we believe, nevertheless, that there exists 
among the Micrasters which d'Orbigny has confounded under the same denomination four 
species very distinct, viz." 

" 1st. The Micraster cor-testudinarium, Goldfuss," admirably figured and described 
by Cotteau. 

"2nd. Micraster gibbus, Agass. Spatangus gibbus, Lam." {Epiaster gibb us oi this 
work.) " Well represented in the ' Atlas de I'Encyclopedie Methodique,' pi. clvi,figs. 4 — 6, 
and remarkable for its elevated conical form, its long straight ambulacra, its large, flat 
under surfaces, truncated posterior border, with its vent placed low down near the angle." 
Remarkable also, I may add, for the want of the subanal fasciole, which has been over- 
looked by Forbes, d'Orbigny, and Cotteau : so that assuming the presence, absence, or 
character or number of the fascioles to afford characters for generic division, this species 
would not belong to the Micrasters at all. 

" 3rd. The Micraster Brongniarti, Hebert, figured for the first time by Brongniart 
in his ' Fossils from the Environs of Paris ' under the name Micraster cor-anguinum, and 

' ' Etude sur les Terr, crdtaces, Mem. Soc. Geol. de France,' 2e serie, torn, v, pi. xxix, fig. 1 9. 



276 MICRASTER 

perfectly characterised by its sub-undulated ambitus, subconvex upper surface, its central 
ambulacral summit, ambitus much grooved by the single ambulacrum, and its narrow 
ambulacra deeply depressed. The 3Iicraster Bronpiiarti appears to be special to the 
Chalk at Meudon, as but one mould has been collected near Sens." 

" 4th. The Micraster cor-angidnum, easily recognised by its cordiforra outline, dilated 
before, acuminated behind, by its elevated and inflated upper surface, convex and rostrated 
in the posterior region, with narrow and shallow petaloid ambulacra ; its ambulacral 
plates shorter and deeper than in its congeners, and by its excentral apical disc placed 
in the direction of the posterior border." 

Locality and StratigrapUcal position. — It is found in all the Upper Chalk districts of 
England, and is common in Kent, Sussex, and Norfolk. It was recorded by General 
Portlock from the Chalk of Magilligan, County Derry, Ireland. 

Toreign Distribution. — This Urchin is one of the most characteristic of the Upper 
White Chalk, equivalent of the ' 22e Etage Senonien,' d'Orbigny. According to that 
author it has been collected in the Anglo- Parisian basin at Meudon (Seine-et-Oise) ; 
Beauvais (Oise) ; in the Somme ; in the Ardennes at Retheil ; in the Seine-Inferieure^ 
at Ciqueport, Etretat, Fecamp, Dieppe, Treport; in the Yonne at Sens, Seigneley, 
Joigny, Villeneuve-sur- Yonne ; in the Eure, at Chateaudun ; in the Sarthe, at Saint- 
Erambault, Roches, Vendome ; in the Loir-et-Cher, at Couture, Villiers, Blois ; in 
I'Indre-et-Loire, near Tours. 

In the Pgrenean basin at Perigueux (Dordogne) , at Moutiers, Cognac (Charente) ; 
at Mirambeau, Coze, Meschers, Saintes (Charente-Inferieure) ; at Tercis, Riviere, near 
Dax (Landes) ; at Mauleon, Magnoac (Hautes-Pyrenees) ; at Bidart (Basses-Pyrenees). 
In the Mediterranean basin at Soulage, Songraigne (Ande) ; at Ayglun, Mers, Beausset 
(Var) ; and in Scandinavia, Germany, Switzerland, and Belgium in the same geological 
horizon. 



Micraster cor-bovis, Forbes, 1850. PL LXII a, figs. 1, 2 a — d. 

MicEASTER COR-BOVIS, Forbes. In Dixon's Geol. of Sussex, pi. xxiv, figs. 3, 4, p. 342, 

1850. 

— — Forbes. Mem. Geol. Surv., decade iii, note, pi. x, 1850. 

— _ Forbes. In Morris' Cat. of Brit. Foss., 2 ed., p. 83, 1854. 

— — Besor. Synopsis des Ecbinides Foss., p. 367, 1858. 

Diagnosis. — Test large, ovate, slightly cordate, broadest in the region of the antero- 
lateral ambulacra. Posterior border obtusely subtruncated. Dorsal surface depressed, 
and slightly elevated in the anterior region above the rest of its surface. Apical disc 
excentral, nearer the anterior border. Anteal sulcus shallow, petaloid ambulacra short, 
unequal in length, and slightly depressed. Base convex, vent in the middle of the 
obtusely sub-truncated border. 



FROM THE WHITE CHALK. 277 

Dimensions. — Length three inches ; breadth two inches and seven twelfths ; height 
one inch and nine twelfths of an inch. 

Description. — My late esteemed colleague in this work, Professor Edward Forbes, 
gave the following note upon this Urchin in Decade HI of the ' Memoirs of the Geological 
Survey,' in his note on allied species of British species of Micrasters : — " I have given an 
account of it in Dixon's work on the ' Geology of Sussex,' where it is excellently figured. 
I have there named it Micraster cor-bovis. It is usually a larger and longer species than 
cor-anguinum, and its petaloidal ambulacra are more deeply impressed and much shorter 
in proportion to the body. The shape is ovato-cordate, the curve of the sides from the 
front of the antero-lateral ambulacra to the anal extremity being but slight, its chief swelling 
being near the anus, and not on a line vpith the postero-lateral ambulacra as in cor- 
anguinum. The back is more equally depressed than in the depressed variety of the last- 
named species. The mouth is much smaller comparatively, and the post-oral spinous space, 
though much longer, in consequence of the elongation of the hinder portion of the test, is 
nevertheless proportionally broader. The tubercles of the plates, whether dorsal or 
ventral, are much smaller and more scattered. Besides all these comparative characters, 
there is the positive one that in cor-bovis the ambnlaci-al plates, instead of being tumid, 
are smooth and plain, as are also the ridges separating the sulcations of the pairs of pores 
in the petaloidal ambulacra. The ambulacral spaces are wider than the breadth of any 
of the sulcations." 

It will be more satisfactory if I here insert Forbes' note from the work referred to : 

" The body of this fine and large Micraster is ovate and slightly cordate, broadest 
in the region of the antero-lateral ambulacra. The posterior end is obtusely subtruncated. 
The dorsal surface is depressed and but slightly elevated in the anterior region above the 
rest of its surface. 

" The ovarian circle is placed nearer the anterior than the posterior end. The frontal 
groove is shallow. The lateral ambulacra are placed in gentle depressions. 

" The postero-lateral ambulacra are very short, and little more than half the length 
of the antero-laterals. There are about thirty pair of pores in each row in the latter and 
about seventeen in each row in the former. The larger tubercles of the dorsal plates are 
much scattered and minute in proportion to the size of the shell. The interstices are 
minutely granulated. 

" The areolated tubercles of the ventral surface are also proportionally small. The 
post-oral spinous space is triangularly lanceolate." 

Affinities and Differences. — This species resembles M. breviporus, of which it has long 
appeared to me to be a gigantic variety. 

Locality and Stratigraphical Position. — Dixon's type was collected from the White 
Chalk, Sussex, others are found at Charing, Kent, and some fine specimens in the 
Woodwardian Museum, Cambridge, vrere obtained from Balsham, near Cambridge ; it 
occurs low down in the White Chalk. 



278 MICRASTER 



MiCRASTER BREViPORUs, AgassiZy 1840. PL LXII a, fig. 3 a — h. 

MicEASTEE BREViPOEUs, Agassiz. Cat. Ectyp. Foss. Mus. Neo., p. 2, 1840. 

— — Agassiz et Besor. Cat. raisonn6 des Echinides, p. 130, 

1847. 

— — ■ (TOrbigny. Prodrome, t. ii, p. 270, 1850. 
^- — Sorignet. Oursins de I'Eure, p. 62, 1850. 

— Leskei (TOrbigny. Paleont. Fran^aise Ter. Cr^taces, tora. vi, 

p. 215, pi. 869, 1853. 

— Besor. Synopsis des Echinides Foss., p. 366, 1858. 

— — Coquand. Synopsis des Foss. des Charentes, p. 134, 1860. 

— — Cotteau. Cat. des Echinid. de I'Aube, p. 34, 1865. 
MiCRASTER BREViPOECS, Egbert. Comp. rend, de I'lnstitut. 25 Juin, 1866. 

— — Schliinbach,. Beitrag. des Griinsandes von Rothenfelde, 

p. 14, 1869. 

— — Be Loriol. Echin. Helv. Echinides Cretacees de la Suisse, 

2nle partie, p. 369, pi. xxxi, fig. 5, 1873. 

Diagnosis. — Test largely cordiform, rounded and grooved before, contracted behind 
and truncated at the posterior border. Upper surface uniformly convex, declining a little 
more anteriorly than posteriorly, with a prominent carina between the apical disc and 
posterior border ; base convex, ambitus slightly undulated, rounded, and inflated. 

Dimensions. — Antero-posterior diameter 1-^ inch ; transverse diameter 1 ^-o inch ; 
height l^ inch. 

Description. — The test of this Urchin has a cordiform shape ; it is rounded and slightly 
grooved anteriorly, and tapers gently to the posterior border, which is truncated down- 
wards and a little inwards. The upper surface is depressed and uniformly convex, and 
declines a little more to the anterior than the posterior border ; a prominent carina more 
or less elevated in different individuals extends backwards from the apical disc to the 
summit of the periprocte, and divides into two ridges, which descend on each side of the 
vent towards the lower part of the posterior border, where they disappear near the 
fasciole. 

The ambulacra are short and straight, very unequal in length, and slightly depressed. 
The anterior single ambulacrum is lodged in a sulcus, which grooves the anterior border 
and extends to the peristome ; its pairs of pores lie wide apart, and are nearly obsolete. 
The anterior pair are large and divergent ; they occupy well-marked depressions, and 
their poriferous zones consist, in one of my specimens, of 30 p^irs of holes, each having a 
connecting groove between the holes. The posterior pair are slightly bent and directed 
backwards, and are about two thirds the length of the anterior pair. The pores are 
similar in structure, and there are 18 to 20 pairs in each zone. The ambulacral plates 
are concave, smooth, and plain, those of the single area alone carrying miliary granules. 



PROM THE WHITE CHALK. 279 

This structure of the ambulacra forms a good diagnostic character between this species 
and M. cor-anguinum. 

The apical disc is very small, and lodged in a valley formed by the confluence of 
the apices of the five ambulacra ; the madreporiform tubercle occupies the centre, sur- 
rounded by four ovarial holes, the posterior pair being wider apart than the anterior 
pair ; the culminating summit of the upper surface being immediately behind the disc. 

The periprocte is situated at the upper part of the obliquely truncated posterior border, 
and its position is persistently the same in all the six specimens before me. 

The base is flattened, the portion between the peristome and anterior border is slightly 
hollowed out. The plastron is wide and filled with large close-set tubercles, these radiate 
in regular rows from a point rising near the middle of the fasciolar line ; the lateral 
portions slope away to the ambitus ; the valleys between indicate the course of the basal 
portions of ambulacra between the border and the mouth, which is situated at a short 
distance from the anterior sulcus, and is bilabiate, and surrounded by a rosette of pores 
and tubercles very regularly arranged in the small specimen figured in 3 b. 

Affinities and Differences. — Micraster breviporiis, which has long been considered to be 
a variety of M. cor-anguinum and of M. cor-testudinarium, is distinguished from them by 
its outline, which is more elongated and depressed, tapering at the sides, and less 
acuminated posteriorly; its upper surface is more uniformly convex, its ambulacral 
summit is excentral and placed forwards, and its petaloidal ambulacra are shorter and 
less depressed, and the ambulacral plates are smooth and not tumid as in 31. cor- 
anguinum. 

Micraster lawoporus, d'Orb., has the summit more central, the ambulacra much more 
depressed, the anterior half of the upper surface more declined, and the posterior half 
more strongly carinated. I have compared my specimens from Brighton and Norfolk 
with a type-specimen kindly given me by my excellent friend M. De Loriol, which was 
collected at St. Julien du Sault (Yonne) ; from the " etage Senonien," equal to our White 
Chalk. M. De LorioP says, "In 1837 M. Desmoulins gave the name of Spatangus 
Leskei to the Urchin figured by Klein under the name Sjjatangus cor-anguinum, var. 
Norvagicum and var. productum, which differs really from the true Spatangus cor-anguinum. 
D'Orbigny and other authors have referred to this Micraster {Spatangus Leskei) the 
species named by the late Professor Agassiz Micraster brevip)orus. Recently M. Hebert 
having been able in Denmark to examine the original specimens of the species which 
Klein had figured under the name Sp. cor-anguinum, var. Norvagicum, has recognised that 
it differs in reality from Micr. breviporus, and that it ought to be separated, and continue 
to bear the name 3Iicr. Leskei, which appears to be a form special to the Upper Chalk 
of the north of Europe. 

Localitg and Stratigraphical Position. — My specimens of this species have been col- 
lected from the Upper Chalk of Brighton, Sussex ; Balsham, Cambridge ; and from the 
1 ' Paleontologie Suisse Echinides Cretaces,' p. 370. 



280 ECHINOSPATAGUS 

Upper Chalk near Norwich, out of the same terrain that yielded Cardiasfer granulosus. 
Card, excentricus, and Epiaster yibbiis. 

In France it has been collected from the White Chalk at Fecamp, Etretat, and 
Dieppe, the environs of Beauvais, Meru (Oise) ; of Vervins and La Capelle (Aisne) j of 
Andelys, Caussols (Var) ; of St. Julien du Sault (Yonne). 

In Switzerland (according to De Loriol) from the Seewerkalk of Sentis (Appenzell) ; 
the Grands Troncs near Semsales (Fribourg), Etage Senonien. 



Genus — Echinospatagus, Breynius, 1732. 

EcHiNOSPATAGUs (pars), Breynius, 1732. 
Spatangds (pars), Klein, 1734. 
Spatangus (pars), Lamarck, 1816. 
ToxASTER (pars), Agassiz, 1840. 

Body cordiform, more or less inflated at the upper surface, and in general flattened 
at the base. 

The pairs of ambulacra petaloidal, unequal in length, always large, and lodged in 
depressions of the test ; poriferous zones wide and slightly unequal in the anterior pair ; 
pores in the form of narrow slits, those of the outer being longer than those of inner 
rows; the anterior poriferous zones are longer than the posterior. The single 
ambulacrum is lodged in a wide, deep, anteal sulcus, its poriferous zones are narrow and 
equal with each other, and the holes are smaller and placed closer together than the 
pores in the pairs. 

The apical disc is compact and solid, composed of four perforated ovarial plates and 
five small oculars, minutely and finely perforated ; the madreporiform body extends into 
the centre of the disc. 

The mouth-opening is situated near the anterior border, and the peristome is small 
and subpentagonal. 

The vent is situated in the upper part of the posterior border, and the periprocte is 

oval. 

The tubercles, of various sizes, crenulated and scrobiculated, are placed in two or 
three irregular rows on the plates ; they are most numerous at the anterior border and 
around the ambitus, and are sparsely scattered on the base ; the surface of the plates is 
likewise covered with a very fine close-set miliary granulation. 

The absence of fascioles from all parts of the test distinguishes this genus from 
Hemiaster, with which it has been often confused. The type-species so common in the 
Neocomian strata of France and Switzerland was first figured by Breynius as Echino- 
spaiaytis cordiformis. 



FROM THE UPPER GREENSAND. 281 

It was afterwards figured and described by Agassiz as Holaster complanatus, and 
subsequently separated from tliat group to form tlietype of his genus Toxaster. As this 
corresponds with the EcMnospataffus of Breynius, the laws of priority demand the 
restitution of the original name, however much we may regret these changes of 
nomenclature. 



EcHiNosPATAGUs MuRCHisoNiANus, Mantell, 1835. PI. LX, figs. 1, a — i, and 

PI. LXIV,fig. 1. 

Spatangus Mukchisonianus, Mantel. Geol. Trans., 2 ser., vol. iii, p. 210, 1835. 

— — Besmoulins. Tableau ties Echinides, p. 412, 1837. 
MiCEASTER MuRCHisoNr, Morris. Catalogue of Brit. Fossils, p. 55, 1843. 

— — Bronn. Index Palscontologicus, p. 724, 1848. 
Hemiaster iN^qCALis, Forbes. Morris's Catalogue of Brit. Foss., 2 ed., p. 81, 

1854. 

— MuRCHisoNi^E. Forbes. Mem. of Geol. Surv., decade v, pi. ix, 1856. 

— — Besor. Synopsis des Echinides Foss., p. 369, 1857. 

— MURCHISONIANUS, De Loriol. Echin. Heiv. Cretaces, t. ii, p. 374, pi. xxxii, 

figs. 4—6, 1873. 

Diagnosis. — Test cordiform, often much inflated, length and breadth nearly equal ; 
round, and largely grooved before, contracted behind, and obliquely truncated on the 
posterior border. Upper surface convex, declining to the anterior side, and having an 
obtuse carina on the single inter-ambulacrum ; anteal sulcus wide and deep ; the pairs of 
petaloid ambulacra unequal in length, and forming deep depressions on the upper surface, 
periprocte oval, opening high on the border. Ambulacral summit excentral, posterior to 
the disc. 

Dimensions. — A. Height, Ijl^ths inch; long., l-njths ; lat., l-i^jths. 

B. Height ?; long., li^ths; lat., li^ths. 

C. Height, ^a^ths ; long., ly^-ths; lat., l-,%ths. 

D. Height, 1 ; long., l-j^ths; lat., l^ths. 

Description. — I have given the dimensions of four typical specimens of this Urchin 
to show its relative proportions. A, the figured specimen, belongs to the British Museum, 
and B, C, D are in my cabinet. A is a very globose form, and B and C are fair types. 
In all the specimens the test is very well preserved, and there is no trace of a peripetalous 
fasciole on any one of them, so I have removed it from the Hemiasters and placed it in 
the genus Ecliinos2Mtagun. 

Professor Edward Forbes studied the specimens of this Urchin in the British Museum, 
and recorded his measurements in the following memorandum. Further, he noted that 

36 



B. 


C. 


li^ 


l-h 


lA 


1. 


OH 


8 

"12 


26 


24. 


36 


30. 


22 


16. 



282 ECHINOSPATAGUS 

they differed from each other considerably in form, and in degree of depth of the dorsal 
ambulacra and the number of the pores in the zones. 

A. 

Length l^s 

Breadth l^ 

Height 1^^ 

Anterior single ambulacrum . . .28 pairs 
Antero-lateral pair „ ... 43 pairs 

Postero-lateral pair „ ... 20 

The anteal sulcus in which the single ambulacrum is lodged is deep, wide, finely 
granulated and tuberculated. The pairs of pores are arranged on the sides of the area in 
single files, and the pores forming a pair are separated from each other by distinct 
tubercles. 

The antero-lateral pair are doubly flexed, and the postero-lateral pair, slightly bent, are 
about half their length. The floors of all the areas arc nearly smooth, and the pores, with 
their small transverse slits in the zones, are set at short distances apart. The portions of 
the test between the petals form obtuse eminences near the apical disc, that body reposing 
at the confluence of the five valleys. On these inter-ambulacral elevations the tubercles 
are more numerous and set closer together than on other portions of the upper surface, 
fig. 1 a and fig. 1 c. 

The apical disc is small, and composed of four perforated, ovarial plates ; the right 
antei'o-lateral is the largest, and supports the madreporiform tubercle on its surface. The 
five ocular plates are very small, fig. 1 //. 

The surface of the plates is finely granulated, among which there are developed many 
well-formed tubercles ; these become more numerous on the sides, they increase in size 
and number at the ambitus, and are large and set closely together at the base, on the 
plastron of which they are very conspicuous, fig. 1 d. 

Mr. Bone copied fig. 1, PI. LX, from Decade V, pi. ix, ' Memoirs of the Geol. Survey.' 
In this figure, drawn under the direction of Professor Forbes, a portion of the surface 
adjoining the right postero-lateral ambulacrum was magnified to show the diffused 
condition of the fasciole. As I have carefully examined many very good tests of this 
species without observing such a structure, I am convinced that a mistake was committed, 
which my friend unfortunately imported into PI. LX, fig. 1 /, of this work, as no true 
fasciole exists in this species. 

The base is flat or rounded, and the peristome situated at the anterior fourth of the 
under surface ; the tubercles on this region are very large, they are raised upon crenulated 
bosses, and their summits are perforated; the areola is surrounded by a chain of 
granules, which completely incircle the areolar boundaries (fig. 1 i). 

Affinities and Bifferences. — This Urchin is well characterised by its large and deep 
anteal sulcus, its bi-flexed antero-lateral ambulacra, the small postero-lateral pair, and 



FROM THE UPPER GREENSAND. 283 

the very excentral position of the ambulacral summit, which is situated behind the centre 
of the upper surface (fig. 1). 

Locality and Stratigraphical Position. — This species is found in the Upper Green- 
sand of Blackdown, Devon, where it is the only Urchin of frequent occurrence, and I 
have no record of its discovery in any other Upper Greeusand locality. 



EcHiNOSPATAGUs CoLLEGNii, Sismouda, 1843. PI. LXIV, fig. 4. 

ToXASTEK CoLLEGNii, Sismonda. Sugli Echini foss. del Contado di Nizza, 

p. 21, pi. i, figs. 9—11, 1843. 

— — Agassix et Desor. Cat. raisonne des Echinides, p. 

132, 1847. 

— Brunneri, Merian. In Desor's Synopsis foss. Echinides, pi. xl, figs. 

2—4, p. 354, 1857. 
EcHiNOSPATAQUS CoLLEGNii, (TOrhigny. Pal. Francaise, Ter. Cretace, t. vi, p. 169, 

pi. Icccxlvi, 1853. 

— — Cotteau. Echinides des Pyrenees, p. 52, 1863. 

— — Cotteau. Echinides de I'Yonne, pi. Ixiv, fig. 11, t. ii, 

1865. 

— — Ooster. Synop. Echin. Suisse, pl. xxv, fig. 8, 1865. 

— — Be Loriol. Echin. Helv. Cretaces, t. ii, pl. xxx, 

figs. 1—5, p. 350, 1873. 

Biaffnosis. — Test largely cordiform ; a little polygonal ; rounded, flattened, and slightly 
depressed anteriorly ; contracted behind and obliquely truncated on the posterior border. 
Upper surface convex, inflated at the posterior half, and much declined from the apical 
disc to the anterior border. Highest point at the ridge behind the apical disc. Poste- 
rior border quadrate, high, strongly and obliquely truncated. Base feebly convex in the 
region of the plastron, and depressed near the mouth. Ihe lateral parts of the ambitus 
inflated. 

Dimensions. — Length 2 inches and 2 tenths ; breadth 2 inches and 1 tenth ; height 
2 inches, 

Bescription. — This large fine Urchin was given to me several years ago by my late 
lamented friend Dr. S, P. Woodward, with the remark that it was said to have been 
collected from the Upper Greensand, Wiltshire, but the species was unknown to him, 
so he begged me to figure and describe it when I came to the group. 

The test is large, cordate, and shghtly polygonal, much elevated behind, and sloping 
from the summit to the anterior border. 

The single ambulacrum is lodged in a large, wide, anteal sulcus, deeper above than 
at the anterior border, which it depresses only feebly ; its poriferous zones are narrow ; 
the pores are nearly equal in size, and set obliquely in pairs. 



284 ECHINOSPATAGUS 

The antero-lateral ambulacra are subpetaloidal, unequal, and lodged in considerable 
depressions of the test. The anterior pair are the largest, and slightly flexed. The 
poriferous zones are unequal in width, the inner being the narrowest. The external 
zone is nearly as wide as the interporiferous space. The pores in both rows are nearly 
equal in size, and are each connected with slitlike depressions of the test. The posterior 
pair are shorter than the anterior. They are nearly as wide and diverge at an angle of 45° ; 
their poriferous zones are nearly equal, and a considerable horizontal ridge separates the 
pair. The plates of the test are sparsely provided with small perforated tubercles, which 
are all raised upon crenulated bosses and surrounded by circular areolas, and the inter- 
tubercular surface is covered with a fine close-set microscopical granulation. 

The apical disc is excentral, placed nearer the posterior than the anterior border, in a 
depression at the ambulacral summit ; from this point the test developes a ridge which 
extends to the posterior border, and the highest point of the test is found one quarter of 
an inch behind the apical disc. 

The posterior border is very much elevated ; it appears to have a quadrate form, is 
sharply truncated, and almost vertical. Tiiis portion of the test is unfortunately broken, 
and it is from the remaining outline that the diagnosis is made. The vent was 
placed high up on the border, but only one side of the periprocte remains to indicate the 
position of that opening. 

The base is flattened in the region of the plastron ; it is slightly convex, and near the 
oral region is concave. The raouth-opening, situated at the junction of the anterior 
with the middle third, is transversely oval or subpentagonal ; the tubercles on the base 
are larger than those on the upper surface. On the plastron they radiate from a central 
point near the posterior border, and have a very symmetrical arrangement on the anterior 
half; around the mouth they are larger and more sparsely distributed, whilst around 
the anterior border and the ambitus they are again more numerous. 

Affinities and Differences. — I have grave doubts about this Urchin being a British 
fossil. The matrix differs froio ^he rock in Wiltshire, which usually yields the Upper 
Greensand fossils of that county, and therefore I record it with reservation ; it certainly 
is the E. CoUer/nii of Sismonda so well figured by Desor in plate 40, figs. 2 to 4, of his 
admirable Synopsis. Unfortunately I have no authentic specimen of this species with 
which to compare it, although I have no doubt as to its identity with the form referred to. 

Stratic/raphical Position. — Said to have been collected from the Upper Greensand of 
Wiltshire. I have no confirmatory evidence of the fact, and give it with proper 
reservation. 



FROM THE UPPER GREENSAND. 285 



EcHiNOSPATAGUs Reneviebi, Wright, iiov. sp. PL LXXV, fig. 1. 

Diagnosis. — Test cordate, much inclined and depressed, the antero-posterior equalling 
the transverse diameter ; ambulacral pairs petaloidal, unequal in length and structure, 
and lodged in slight depressions. Anterior pair much flexed ; poriferous zones nearly 
equal, the inner a little narrower than the outer row ; posterior pair short, curved ; zones 
equal. Ambulacrum wide, lodged in a deep depression. Test elevated in posterior half 
and tapering behind to a point ; anterior half sloping rapidly to anterior border ; base 
flat. 

Dimensions. — Length 1 inch and 4 tenths ; transverse diameter 1 inch and 4 tenths ; 
height 8 tenths of an inch. 

Description. — This Urchin was catalogued by the late Dr. Eitton as Holaster 
-complanatus in his lists of fossils from the inferior beds of Lower Greensand exposed at 
Atherfield, Isle of Wight. A careful examination of all our Neocomian Echinides, 
however, has proved that, although H. complanatus forms a leading fossil in the Lower 
Neocomian strata of France and Switzerland, it has never yet been found in England. 
I have searched carefully most of the public and private collections to find an English 
specimen, but hitherto without success. Any so-called examples that I have found in 
the cabinets of my friends were in reality foreign specimens purchased from dealers. 

The outline of E. Benevieri is peculiar, it being as broad as it is long, and 
terminating behind in a pointed process. This character at a glance distinguishes it ; 
but when added to others which I shall now point out it renders the difference wider at 
■each step of the demonstration. 

The ambulacral pairs are petaloidal and lodged in depressions, whereas in H. 
complanatus they are superficial. The anterior pair are gently flexed, and the poriferous 
^ones are nearly of the same width ; the posterior pair are short and curve inwards, and 
have equal-sized poriferous zones. The ambulacrum is lodged in a wide anteal sulcus, 
which is deeper above than at the border. The poriferous zones consist of equal-sized 
holes placed in oblique pairs. 

The apical disc is small, and the ambulacral summit excentral ; it is much nearer the 
posterior than the anterior border, and the highest point in the test is on an elevation 
immediately behind the apical disc. The posterior third of the upper surface is 
considerably elevated, and the two anterior thirds slope gradually to the border, which 
imparts a marked character to the test. 

The posterior border is narrow and obliquely truncated downwards and inwards. It 
is unfortunately covered up with a very hard matrix, which cannot be removed without 
risk to the specimen. 



286 ECHINOSPATAGUS 

The base is flat and partially covered, and the position of neither the mouth-opening 
nor the vent is shown. 

Affinities and Differences. — It certainly resembles some specimens of Toxaster 
coviplanatus, but differs from all in the form of the test, being as broad as it is long ; its 
greatest ti'ansverse diameter is about the middle of the test. From this point the 
anterior portion of the ambitus maintains its rounded outline, whilst the posterior 
portion rapidly contracts to form the narrow truncated posterior border. 

The pairs of petaloidal ambulacra are lodged in depressions of the test, whilst they 
are quite on the general surface without depressions in T. complanatus. The conical 
elevated portion of the upper part of the posterior border is likewise very di0"erent from 
the broadly truncated posterior border in T. complanatus. For these reasons I have 
grouped it with the Echinospataffi, and dedicated the species to Professor E. Renevier, of 
Lausanne, who collected the specimen at Shanklin, Isle of Wight, and gave it to our 
mutual friend Monsieur De Loriol, to whose cabinet it belongs. 

Locality and Strati grapMcal Position. — Found in the inferior beds of Lower Green- 
sand at Shanklin, Isle of Wight, in the hard grey sandy rock with numerous oolitic 
grains of silicate of iron, and which contains fine specimens of Gryphcea sinuata and 
Ostrea carinata, with the Echinides Clypeopyc/us Fittoni, Wr., and Enallastcr Fittoni, 
Forb. It is, therefore, derived from one of the richest Urchin-beds of the Neocomian 
series in the Isle of Wight. 



EcHiNosPATAGUs Qdenstedtii, Wright, nov. sp. PI. LXXV, fig. 2. 

Diagnosis. — -Test cordate. Upper surface convex, very much declined, length and 
breadth nearly equal. Ambulacral pairs unequal, lodged in shallow depressions. 
Anterior pair lanceolate, not flexed ; form an angle of 40". Posterior pair short ; form 
an angle of 45°. The poriferous zones of both pairs equal. Ambulacrum long, anteal 
sulcus shallow, poriferous zones not longer than the anterior pair, only grooving the 
anterior border very little. Ambulacral summit excentral, situate at the junction of the 
posterior with the middle third. Posterior border truncated concavely. Flanks sloped 
inwards. Base small, flat ; mouth-opening transversely oblong near the ambitus. Vent 
high up in the border; periprocte oblong ; upper point extending to the beak-like process 
of the test. 

Dimensions. — Length 2 inches and 1 tenth ; breadth 2 inches and 2 tenths ; height 
at vertex 1 inch and 2 tenths. 

Description. — This Urchin was collected from the fine sandy calcareo-micaceous beds 
of Lower Chalk or Upper Greensand in Wiltshire ; it is always more or less completely 
denuded of the plates of its test, and is found in the form of moulds. The fineness of 



FROM THE UPPER GREENSAND. 287 

the matrix fortunately produces a very sharp cast of the interior, and as the shell was 
very thin the outline of its structure is very well preserved. 

The ambulacral pairs form quite a " crux Andrese " on the convex surface of the highly 
inclined dorsal surface. They were lodged in very shallow depressions, and pass nearly 
straight out from the summit to the ambitus. The anterior pair are lanceolate and 
moderately long, and the posterior pair short, extending half the distance between the 
disc and the border. The poriferous zones in both pairs are nearly equal. The single 
ambulacrum lies in a shallow anteal sinus, which scarcely grooves the anterior border. 

The ambulacral summit is extremely excentral, the disc being near the junction 
of the posterior with the middle third. 

The upper surface is convex and very much inclined. The posterior third is the 
highest, and the two anterior thirds slope sharply down to the border forming an angle 
of 20°. 

The anterior border is thin, the sides inflated, and bevelled away towards the base 
and posterior border, which is truncated concavely, and has a portion of the upper 
surface overhanging it above. In this beak-like projection the vent is situated. The 
periprocte is oval, the upper end reaching near to the border. 

The base is flat. The mouth-opening is situated near the border, and the peristome 
is narrow and transversely oval ; the plastron is a little convex near the border. 

Affinities and Differences. — This species resembles E, Benevieri in its cordiform 
outline and highly inclined upper surface. It difi"ers, however, in the shallowness 
of its ambulacrum and in the absence of depressions for the petaloidal ambulacra, which 
are straight in E. Quenstedtii and flexed in E. Benevieri. 

Locality and StratiffrajiMcal Position. — The only two specimens I have obtained 
were collected from the fine marly micaceous beds of the Upper Greensand of Wiltshire. 

I have dedicated this species to Professor Aug. Quenstedt, of Tiibingen, whose 
magnificent works on the Cephalopoda, Echinodermata, and ' der Jura ' of Wiirtemburg 
have so greatly advanced the palaeontology of the Jurassic Formations. 



288 ENALLASTER 



Genus. — Enallaster, d' Orbigny, 1853. 

Hemipneustes, Forbes, 1852 (non Agassiz, 1836). 
ToxASTER, Roemer, 1850 (non Agassiz). 
Enallastee, Be Loriol, 18/3. 

Test more or less cordiforrn. 

Ambulacral summit subcentral. 

Ambulacral pairs subpetaloidal, unequal, and depressed. 

Poriferous zones in the anterior pair unequal. The posterior zones are much larger 
and wider than the anterior zones. In the small short pair of posterior ambulacra the 
poriferous zones are equal. 

The anteal sulcus wide. Single ambulacrum, one third wider than the laterals, has 
narrow poriferous zones, in which each pair of holes are set well spaced out and disposed 
very oblique to each other ; a small tubercle rising from the surface of the partition wall 
between the pores divides them, and developes an ornamental beaded line on each side of 
the area. 

Apical disc small, compact, with four perforated ovarial and five perforated ocular 
plates. 

Mouth near the anterior border. Peristome subpentagonal, with well-defined 
margin. 

Vent in the middle of the truncated posterior border. Periprocte oval, with well- 
defined margin. 



Enallaster Eittoni, Forbes, 1852. PI. LXV, figs. 1 a—/, 2 a — c. 



Hemipneustes Fittoni, Tories. Mem. Geol. Surv., decade iv, pi. v, note, 1852. 

— — Forbes. Morris. Catalogue of British Fossils, 2 ed., p. 82, 

1854. 
Enallastek Fittoni, B6sor. Synopsis des Echinides fossiles, p. 357, pi. xl, figs. 

5—7. 1857. 

— — Jaccard. Jura Vaudois et Neucbatelois, p. 134, 1869. 

— — Be Loriol. Ecliin. Helv. Cretaces, t. ii, p. 359, pi. xxx, 

fig. 9, 1873. 

Diagnosis, — Test oval, cordiform, rounded and sinuous before, contracted behind. 



FROM THE LOWER GREENSAND. 289 

and obliquely truncated posteriorly. Upper surface convex, elevated, and declining 
towards the anterior border ; base flat, with peristomal depression. Sides rounded and 
inflated, ambulacral summit excentral, and posterior ; periprocte oval, situated high up in 
the border. 

Dimensions. — Antero-posterior diameter one inch and i^jths ; height^ one inch ; 
transverse diameter, one inch and 2^ths. 

Description. — The test is sometimes cordiform, tapering slightly from the anterior 
third to the posterior border ; in other specimens it is oval, its greatest diameter being 
about the middle of the ambitus, from whence it diminishes anteriorly and posteriorly. 
The anteal sulcus is shallow, and the pairs of ambulacra are unequal in length and not 
much depressed (fig. 1 a). 

The antero-lateral pair are only partially petaloid, they are long, wide, and depressed 
in their upper third, are arched above and divergent below. The poriferous zones are 
very unequal, the anterior are very narrow and composed of small, oblong, almost equal 
pores, each pair being disposed obliquely circumflex (fig. 2 c). 

The posterior are much larger, and formed of elongated pores, of which the external 
are nearly twice as long as the internal series, and there are about 36 pairs of pores in 
the petaloid portion of each row. The postero-lateral ambulacra are much shorter and 
more symmetrical in structure, and their poriferous zones are nearly equal ; there are 
about 16 pairs of pores in the petaloid parts of each row. The anterior single 
ambulacrum is lodged in a shallow anteal sulcus, and is wider than the antero-lateral pair. 
It preserves a nearly uniform width throughout, and is composed of small plates, which 
become gradually contracted vertically throughout its upper half (fig. 2 b), a character 
which appears to be generic rather than specific in all the Enallasters that have passed 
through ray hands. 

In the lower half of the areas the plates are large, square, or oblong ; they are each 
perforated near their lower and outer corners by a pair of minute approximated pores. 
In the upper half of the area the plates become narrow, and the poriferous zones are here 
very conspicuous ; each pair of pores is set obliquely in a kind of circumflex manner with 
a prominent tubercle marking the divisional partition between them (fig. 2 b), a singular 
character which was not well shown in the figured specimen, although it is well marked 
in others in which the tubercles of the test have been preserved. The surface of the 
plates is covered with minute granulations, closely set together in transverse rows. 

The apical disc is small and compact, the four genital plates are perforated, and the 
right antero-lateral extends into the middle of the disc, with the madreporiform body on 
its surface ; the elements of the disc are closely blended with the areal plates (fig. 2 b). 

Peristome subpentagonal and lodged in a depression ; it is encircled by a smooth 
border, and is elongated transversely (fig. 1 b). 

The periprocte is small and oval, and opens at the summit of the truncated posterior 
border, within a smooth, undefined, anal area (fig. 1 a and d). 

37 



290 ENALLASTER 

The tubercles are very small, and developed chiefly on the sides and base (fig. 1 b), 
on the convex upper surface they are nearly absent (fig. 1 a) ; they are largest on the 
anterior and lateral portions of the base (fig. 1 b), and on the plastron they are more 
regularly arranged ; the miliary granides are very small, and set closely together over 
the surface of the plates and around the tubercles, as seen in fig. 1/, where two large 
plates and a portion of one of the ambulacral areas is magnified three diameters. 

A^nities atid Differences, — It is distinguished from Eaallaster Greenovii by a smaller 
and narrower anteal sulcus, and by a diSerence in the structure of the antero-lateral 
ambulacra, the size of the poriferous zones, and the form of the pores therein. 

Locality and Sfratif/rajjMcal Position. — This species has been collected from Horse- 
ledge Point, near Shanklin, Isle of AVight, from beds of Lower Greensand, where it is 
very rare. I have found it in beds of the same age at Atherfield, and it is a leading 
fossil of these beds in the Island. It has been collected from the Lower Greensand at 
Hythe. My friend M. De Loriol gives La Presta (Neuchatel), Sainte-Croix (Vaud.), as 
localities in Switzerland, where it is collected from the yellowish marl belonging to tlie 
Etage Aptien inferieur. 



Enallaster Greenovii, Forbes, 1852. PI. LXIV, figs. 2 a—f, 3 a—d. 

Hemipxecstes Greenovii, Forbes. Mem. Geo). Surv., Decade iv, pi. v, 1852. 

— — — In Morris' Catalogue British Foss., 2 ed., p. 82, 

1854. 
En.^i.lastee Gkeekovii, d'Orhigny. Paleont. Francaise, Terrains Cretaces, tome vi, 

p. 183, pi. 849, 1855. 
— — Bisor. Synopsis des Echinides Foss., p. 358, 1858. 

Diagnosis. — Test cordiform, enlarged and sinuous before, contracted and truncated 
behind ; upper surface convex, and declined towards the anterior border. Anteal sulcus 
large, and wider in the middle. Antero-lateral ambulacra long, biflexed ; poriferous 
zones unequal ; internal row formed of small, simple, close-set pores. Postero-lateral 
pair of short zones equal ; posterior border obliquely truncated ; periprocte in the upper 
third. 

Dimensions. — Fig. 1 . Antero-posterior and transverse diameters 1 inch and 4 twelfths ; 
height 1 inch. 

Fig. 2. Antero-posterior and transverse diameters 1 inch and 1 twelfth ; height 
8 twelfths of an inch. 

Description. — This interesting Urchin has a regularly cordate outline, nearly as wide 
as long, rounded and sulcated anteriorly, and bluntly truncated posteriorly. Its tumidity 



FROM THE UPPER GREENSAND. 291 

varies in different specimens, and the posterior is always higher than the anterior half of 
the test. The sides are much inflated, and the base is slightly convex (figs. 2 a and 2 b). 

The anterior single ambulacrum is a third wider than the pairs. According to Forbes 
it preserves nearly a uniform width, and is composed of plates which become contracted 
vertically throughout the upper half (fig. 2 a). Out of the thirty-seven plates seen in each 
of its two series the lower seven are square or oblong and large (fig. 2/). They are each 
perforated near their ohter and lower corners by a pair of minute approximated pores. 
In the narrow plates above these a very curious change takes place in the avenue arrange- 
ments for the pairs of pores ; all become conspicuous, are alternately approximated, and set 
widely apart, the latter pairs each consisting of a long outer pore and a shorter inner one 
(fig. 2/). Inside of the pores there is a very small tubercle or two on each plate, the rest 
of the surface being covered by minute and closely set granulations ranged in transverse 
rows. The antero-lateral ambulacra are undepressed and superficial, and exhibit a slight 
and graceful curve ; they are composed of an inner series of minute and approximated 
pairs of pores, and an outer or hinder series in which the pores of each pair are widely 
separated and unequal (the outer ones being the longest), and connected by a shallow 
groove. There are about thirty pairs of pores in the petaloidal portion of each series ; 
the petals are also plain and undepressed, but are more regularly lanceolate in shape in 
consequence of the two series of pairs of pores in each being of nearly similar structure 
and but slightly unequal in width. There are about eighteen pairs in each petaloid avenue. 
A few tubercles (fig. 3 h) are seen upon the lateral ambulacra. On the interambulacral 
spaces they are much more numerous though set well apart and much larger. They are 
largest on the anterior segments, where they have wide areolae (fig. 3 c). Their inter- 
stices over the whole of the test are occupied by minute granules, which are, however, not 
so small or so regularly arranged as those on the odd ambulacral plates. On the under 
surface the tubercles are confined for the most part to the interambulacral spaces, and 
are especially numerous, regular, and closely set on the ovato-lanceolate post-oral space 
formed by the inferior portion of the hinder ambulacrum (fig. 2 h). This space exhibits a 
prominent caudal gibbosity. The tubercles are minute and perforated ; they are elevated 
upon crenulated bosses (fig. 3 f/). The tracks of the ambulacra are naked. The spines 
are unknown. 

The apical disc is small, and is composed of four perforated genital plates, the 
perforations of which are approximated. In the midst of tliem is seen the madre- 
poriform body. A fifth genital plate is imperforate; the five ocular plates are all 
perforated, but very minute (fig. 2/). 

Affinities and Differences. — It very much resembles E. Filtoni in its form, outline, 
and tumidity. It is, however, a larger Urchin, with larger tubercles on the upper surface, 
and having them more sparsely distributed on the plates. 

Locality and Stratigrapltical Position. — The specimens I have figured are in 
the Museum of the Royal School of Mines, and are the same which were so beautifully 



292 ECHINOCORID^. 

drawn by Mr. C. R. Bone for my late esteemed colleague Professor Edward Forbes, whose 
accurate description I have adopted. They were collected from the Greensand of Black- 
down in Devonshire, a formation whose geological horizon is probably about the junction 
of the Gault and Upper Greensand, and I am not aware the species has been found in any 
other locality. 



Family 13. — Echinocorid^, Wnc/ht, 1856. 

The Urchins of this family have an oval, cordate, or conoidal test, which often attains 
a considerable size. 

The ambulacra! areas are equal, narrowly lanceolate, and converge to one ambulacral 
summit, which is always the vertex of the test. 

The poriferous zones are narrow, and the pores are disposed in pairs at some distance 
apart. 

The surface of the plates of both areas has in general two horizontal rows of very 
irregular, small, perforated tubercles, raised upon bosses with crenulated summits, and 
having around their bases a circle of very small granules ; the entire surface of the plates 
in some well-preserved tests is likewise covered with a profusion of similar microscopic 
granulations. 

The mouth-opening is always placed near the anterior border ; it is transversely 
oblong, and often bilabiate ; the vent is round, and opens either at the base, near the 
margin, or in a supra-marginal region of the posterior border in different genera. 

The apical disc is usually narrow and much elongated ; it consists of four perforated 
and one unperforated ovarial plate, with five perforated oculars : the whole of the 
elements are well soldered together, and often covered over with a thin granulated layer 
of the test, which conceals the sutures of the disc and converts the whole into a single 
mass. In the genus Stenonia the apical disc is short and compact ; it is likewise small 
in Holaster and Cardiaster, and large and elongated in Echinocorys. 

The cordate forms have an anteal sulcus feebly shown in Holaster, but largely developed 
in Cardiaster, whilst in the conoidal forms, as Echinocorys and Stenonia, it is absent. In 
the genus Cardiaster there is a marginal fasciole, which passes under the periprocte. 

The EcniNocoRiDiE are an extinct family of the cretaceous period, and the species are 
distributed throughout all the rocks of this formation from the Neocomian strata up to 
the beds of uppermost White Chalk. One living form which connects this family with 
the SpatangiDjE ought, perhaps, to be placed here, the genus Palaopneustes^ Agassiz, 
a singular Urchin which was dredged near Barbadoes by the Hassler expedition. 



CARDIASTER. 293 

The extinct genera are : 

EcHiNOCOBYS, Breynius. Holaster, Agassiz. 

Stenonia, Desor. Cardi aster, Forbes. 

All the extinct genera are found in British rocks with the exception of Stenonia, 
which is collected only in the White Chalk of Italy, or Scaglia of the Vicentin, at 
Monte di Magre. The living genus Pa^opneustes, Agassiz, has at present an 
" incertum sedis " in this group. 



Genus — Cardiaster, Forbes, 1850. 

Spatangus, Auctorum. 
Holaster (pars), Agassis. 
Infclaster, Borchards. 

Test cordate, tumid, or depressed ; lateral ambulacra having the upper part of their 
avenues slightly dissimilar ; all the ambulacra convergent on the vertex, the anterior 
single ambulacrum lodged in a strongly marked anteal sulcus with angulated borders. 
A fascicle passing beneath the vent and continued on the sides. Apical disc elongated, 
and composed of four perforated genital and five perforated ocular plates. Tubercles 
perforated, raised upon crenulated bosses, and surrounded by areolae. 

Cardiaster possesses all the characters of Holaster, from which it is distinguished 
by the presence of a subanal fascicle, and a deeper anteal sulcus with more angulated 
sides. 



Cardiaster Benstedi, Forbes, 1852. PI. LXVI, figs. 2>a,b,c; PI. LXXI, figs. 4 and 5. 

Cardiaster Benstedi, Forbes. Mem. of Geol. Survey, decade iv, pi. ix, notes, 1852. 
— — Morris. Catalogue Brit. Foss., 2nd edit., p. 73, 1854. 

Diagnosis. — Test cordiform, broad, hemispherical, upper surface convex, rotund, 
anteal sulcus shallow, lateral ambulacra narrow, poriferous zones narrow and unequal. 

Dimensions. — Length one inch and a half; breadth one inch and a half; height one 
inch. 

Description. — The anteal sulcus is strongly marked and wide below. The upper surface 
is gently curved, convex, and rotund. The poriferous zones are all remarkably narrow, 
and the posterior as broad as the antero-laterals. PI. LXVI, fig. 3 a, represents the upper 
convex surface, showing the very narrow zones with the central apical disc and its four 



294 CARDIASTER 

perforated ovarial plates. Fig. 3 b gives a lateral view, showing the increased elevation 
at the anterior third, and fig. 3 c shows the position of the vent with its oval periprocte 
in the posterior border. PI. LXXI, figs. 4 and 5 are figures of this Urchin from the 
Lower Greensand of the Isle of Wight. This species was first described by Professor 
Edward Forbes in the ' INIemoirs of the Geological Survey,' decade iv, in his notes on 
British species of Cardiasters appended to his description of pi. ix. It was collected 
from the Lower Greensand of Maidstone, and presented to the Royal School of Mines 
Museum by Messrs. E. H. Bunbury and Professor Morris. The specimens were too 
imperfectly preserved to be described. The one that forms the subject of our figure in 
PI. LXVI belongs to the collection of the British Museum, and I understand it was 
collected from the same rock and locality. 

The test is broad, cordate, and hemispherical, convex on the upper surface, and 
inflated at the sides. The anteal sulcus is wide below and shallow in the upper part; 
the ambulacrum smooth in the middle, with a row of tubercles on each side of the angles ; 
the pores are minute, remotely placed in oblique pairs ; the antero-lateral ambulacra are 
narrowly lanceolate ; the poriferous zones contracted, and the pores are like fine slits set 
wide apart ; the postero-lateral pair are about the same width but shorter than the 
anterior pair. The surface of all the plates is covered with a minute, close-set granulation, 
and at the anterior border a few irregular rows of larger tubercles are developed. The 
back is gently curved towards the upper angle of the vent, which occupies the middle of 
the posterior border (PI. LXVI, fig. 3 b, c, and PI. LXXI, fig. 4 d). 

The base is much distorted in most of the specimens, appears to have been flat and 
had numerous rows of large tubercles set upon the central plastron, and the sides and 
anterior portion. 

The mouth-opening is situated near the anterior border ; it is transversely oblong and 
bilabiate (PL LXXI, fig. 4 b), the peristome is, unfortunately, displaced in the specimens 
that have come into my hands. 

The apical disc is small, consisting of four pairs of perforated ovarials and five per- 
forated ocular places (PL LXXI, fig. 4 a ; PI. LXVI, fig. 3 a). 

The posterior border is small, narrow, and truncated (PI. LXXI, fig. 4 ^; 
PI. LXVI, fig. 3 c), and the vent opens in its upper portion. 

Affinities and differences. — This species, originally proposed by Professor Edward 
Forbes for an Urchin from the Lower Greesand of Maidstone, which he considered to be 
distinct from any other species, is characterised by the following diagnosis : — " C. late 
cordatus, subJtemispJKsricus, dorso rotundato, sericbm pororum omnibus angmtis sub- 
equalibus. The anterior sulcus is strongly marked and wide below. The back is gently 
curved. The vent is medial in position as compared with its height. The poriferous 
avenues are all remarkably narrow, and the hinder ones as broad as the antero-laterals. 
The surface of the test is too imperfectly preserved to be described." Since the date of 
this description several specimens have been found in the Lower Greensand at Atherfield, 



FROM THE LOWER GREENSAND. 295 

Isle of Wight, iu nodules from the Walpen and Ladder Sands and Clays, with 
GryjAma sinuata and Ammonites {HopUtes) Martini, d'Orbigny, and in the bed with 
GryphcBa at Shanklin Point, where several other Urchins, as Clypeopygus Fittoni, Wright 
and EcUnospataguH Benevieri, Wright, have been found. The affinities of this species 
are certainly with Cardiaster fossarius, the smaller forms of which it closely resembles in 
many points of structure. The narrowness of the poriferous zones, common to both 
forms, cannot afford a specific character ; therefore, until better examples are found for 
comparison, I must regard the distinction between C. Benstedi and C. fossarius as 
doubtful. 

Locality and Siratiyraphical Position.— Xwik^ Lower Greensand of Maidstone, and in 
the Lower Greensand at Shanklin and Atherfield, Isle of Wight. 



Cardiaster latissimus, Ayassiz, 1840. PI. LXVII, figs. 1, 2 a — h. 

HoLASTER LATISSIMUS, Jffossis. Catalogus Syst, p. 2, 1840. 

— — Agassiz et Desor. Cat. Raisonu^, p. 133, 1847. 

— — d'Orbigny. Prodrome, t. ii, p. 177, 1847. 

— — d^Orbigny. Paleont. Frau^aise, Ter. Cret., torn, vi, 

p. 92, pi. 837 and 838, 1853. 
Cardiaster suborbicularis, Forbes. Mem. Geo!. Surv., decade iv, pi. ix, notes, 1852. 

— — Morris. Catal. Brit. Foss., p. 73, 1854. 

Diagnosis. — Test cordiform, broader than long, much depressed; anterior border 
very wide, deeply grooved by the anteal sulcus, sides expanded ; posterior half contracted 
and becoming rapidly narrow behind, upper surface slightly convex ; anterior half more 
rotund and elevated than the posterior half, which devclopes a ridge between the disc and 
the posterior border, this region is narrow, elevated, and obliquely truncated, having the 
vent high up near the dorsal surface. Ambulacral pores narrow, poriferous slightly 
unequal. Anteal sulcus deep, ambulacrum with very minute round pores. Base slightly 
convex, depressed near the mouth, convex and elevated in the middle and posterior 
region over the plastron. 

Dimensions. — Large specimen, fig. 1. Antero-posterior diameter two inches and 
-i%ths; transverse diameter two inches and iijths ; height y^ths of an inch. 

Small specimen, fig. 2. Antero-posterior diameter two inches and i^ths; transverse 
diameter two inches and -i%ths ; height anteriorly -j^ths of an inch, posteriorly i^ths of 
an inch. 

Description. — This beautiful Cardiaster is entered in our catalogues of British 
Urchins as C. suborbicularis. It appears, however, to be identical with Holaster 



296 CARDI ASTER 

latissimus, Agassiz, so well figured in the ' Paleontologie Pranfaise.' A careful 
comparison of the two fine specimens before me, which formed the subjects of our plate, 
with three specimens of C. orhicidaris from the Etage Cenomanien de Cap-le-Heve, shows 
that Cardiasfer latissimus is more depressed and proportionately wider to its length than 
the specimens of C. suborbicularis from Havre measured by me. Moreover, in the 
latter the under surface is more convex, and the plastron ridged, and the posterior border 
more elevated than in our English specimen. I have lately had the advantage of 
examining at Auxerre my friend Monsieur G. Cotteau's magnificent collection of recent 
and fossil Echinodermata, and of comparing Cardiasfer orbicularis and C. latissimus with 
each other, and find that his type-specimens of the latter species are identical with the 
Echinide I have figured under that name from the Upper Greensand of Dorsetshire. 

The body is cordiform and much depressed, it is rounded before, and deeply grooved 
by the anteal sulcus, the sides are widely expanded, and the posterior border is 
contracted and acuminated. The upper surface is convex and a little more elevated at 
the anterior than at the posterior third ; a ridge rising along the middle line from the 
disc backwards gives a marked character to the smaller specimen (figs. 2 b and c). The 
pairs of ambulacra are unequal. The anterior pair are slightly curved outwards and 
forwards, and the posterior are shorter and directed straight outwards and backwards 
(figs. 1, 2 ^). The poriferous zones are narrow, and composed of small equal-sized 
holes (fig. 2 e). The anterior single area is lodged in a deep sulcus, the zones are feebly 
developed, and the holes very minute (fig. 2/). The surface of the plates, especially 
those about the anterior border and the base, has a number of small tubercles developed 
on their surface (figs. 2 a and 2 e). The tubercles are mammillated, with crenulated 
bosses and perforated summits (fig. 2^). The apical disc is small and elongated, with 
four perforated ovarial plates (fig. 2 h) and five small oculars. 

The under surface (fig. 2 a) is flattened, a little convex in the region of the plastron, 
and concave at the sides and around the anterior border. The mouth-opening is placed 
in a depression near the junction of the anterior fourth with the middle fourths of the 
base. The peristome is small and bilabiate (fig. 2 a). The arrangement of the tubercles 
on the base is very well shown in this drawing, which gives a more correct notion of 
their comparative size and distribution than any description can convey. 

The vent is situated high up in the posterior border (fig. 2 c), which is narrow and 
truncated obliquely downwards and inwards (fig. 2 b), with a beak-like process 
overhanging the upper angle of the vent, the periprocte of which has an oval form 
(fig. 2 c). 

Affinities and Differe7ices. — I have already pointed out the affinities and diff'erences 
subsisting between this species and C. suborbicularis; there is no other congeneric 
form in our Upper Greensand strata with which it can be confused ; it is altogether a 
very rare form in our area. 

Locality and Stratitjrapldcal Position. — The large specimen was obtained from the 



FROM THE UPPER GREENSAND. 297 

Upper Greensand of Golden Cap, near Bridport, on the Dorsetshire coast, and the small 
specimen from the Cowstones, Upper Greensand, at Black Ven, near Lyme Regis, Dorset, 
and all the other British specimens on record were collected from the same beds on the 
Dorset coast. It appears, however, to be a very rare form in that county. 

In France it is found in the Cenomanien at Havre, and at Grand-Pre, Meuse, and 
Ardennes, in the same etage. 

The specimen in the Royal School of Mines, Jermyn Street, is from the Upper 
Greensand- of the neighbourhood of Osmington, in Dorsetshire, where it was obtained by 
Mr. E. H. Bunbury, who presented it to the Museum of that Institution. 



Cardiaster fossarius, Bcnett, 1831. PI. LXVIII, figs. 1 a — e. 

Spatanous rossABicrs, Benett. Catalogue of Upper Greensand Fossils, p. 7, 1831. 
HoLASTER Greenoughii, Affossiz and Desor. Cat. Raisonee, p. 133, 1847. 
MiCRASTER FOSSARIUS, Morris. Catalogue of Brit. Foss., p. 54, 1843. 
Cardiaster — Forbes. Mem. Geol. Surv., decade iv, pi. ix, notes, 1852. 

— — Forbes. Morris's Catalogue, 2 ed., p. 73, 1854. 

— — D'Orbigny. Paleontologie Francaise, Ter. Cretace, tome vi, 

p. 124, pi. 820, 1855. 

Diagnosis. — Test large, cordiform ; length and width nearly equal, greatest diameter 
at the anterior third ; deeply grooved at the anterior border, with prominent marginal 
carinse, much elevated anteriorly and contracted posteriorly; the highest point of the test 
behind the ambulacral summit ; posterior border truncated ; base slightly convex, with 
an elevated ridge on the plastron, periprocte in the upper part of the border having a 
blunt carina extending from its upper part to the disc ; test covered with very small 
tubercles. 

Dimensions. — Antero-posterior diameter, 2 j^ inch ; transverse diameter, 2 ^-q inch ; 
height, \^Q inch. This is the size of the large figured specimen. Smaller tests which I 
have measured bear the same relation in their several diameters to each other as that 
given for the type. 

Description. — This is the fine Wiltshire Cardiaster long ago mentioned in Miss 
Benett's ' Catalogue of Wiltshire Fossils ' as Spatanous fossarius. A specimen of this 
species was sent by Mr. Greenough to the Paris Museum, which was entered in Agassiz 
and Desor's ' Catalogue Raisonne ' as Ilolaster Greenoughii. It has been long a leading 
fossil Urchin in the Upper Greensand of Wilts, and appears to be special to that English 
formation, as I have not found any specimen approaching this form from the Cenomanian 

38 



298 CARDIASTER 

Stage on the Continent. The test is largely cordiform, having the length and breadth of 
nearly equal diameters ; the anterior border is convex, with a deep anteal sulcus, having 
sharply defined carinal borders extending upwards towards the apical disc ; the summit 
of the ridges forming the sides of this sulcus attain the highest point in the test. The 
posterior Iialf of the shell tapers considerably towards the posterior border, which is 
narrow, truncated, and depressed. The sides and border are slightly angular from the 
way the broad plates forming the interambulacra areas are bent, and this angularity 
imparts a very marked character to the tests of this Urchin. Figs. 1 a and c show these 
angles fairly well. 

The ambulacral areas are of unequal width ; the anterior pair are the longest and 
largest, and extend across the test ; their poriferous zones are unequal, as the inner series 
have the pores more nearly approximated than those of the outer series ; the apertures 
have the form of narrow slits, and the pairs of pores are placed close together in the 
upper part of the zones, but become wider asunder as the discal distance increases, so 
that at the middle of the side they are much wider apart, and on the lower part of the 
ambitus quite remote from each other (figs. \a,c). 

The posterior pair of ambulacra are much shorter and directed backwards ; the pores 
in their zones are likewise in the form of slits, and become in like manner wider asunder 
as they descend the area. The ambulacra and poriferous zones are in no way depressed, 
and occupy the surface of the test (figs. 1 c, d). 

The inter-ambulacral areas are very wide, and built up of long plates, which are bent 
transversely near their middle ; this bending of the plates produces the angles in the test 
already referred to ; between the antero- and postero-lateral ambulacra the angles are 
marked out by a series of knotty lines along the sides of the test, and a similar ridge 
runs between the antero-lateral ambulacra and the prominent sides of the anteal sulcus, 
so that the angularity of the test is an interesting character of this species. 

The upper surface is covered with very minute tubercles, which become a little 
larger on the anterior border and are still larger on the sides of the anteal sulcus. 

The apical disc is small, and well soldered into the plates of the test ; there are four 
perforated ovarials, and five ocular plates. 

The under surface is convex and angular ; the plastron forms a prominent ridge, 
which divides the posterior half along the mesial line, and it becomes concave at the 
anterior third where the mouth is situated (fig." 1 b) ; the basal plates are covered with 
larger tubercles, which have a well-defined arrangement on the plastron and on the 
lateral parts of the base (fig. 1 h). 

The mouth-opening is near the anterior border ; it is a wide opening, transversely 
oblong, with a well-defined peristome and rudimentary labial process. 

The vent is oval, and situated in the upper part of the posterior border, which is 
depressed (fig. 1 d) ; two ridges extend vertically along the sides of the border, and 
increase the depth of the concavity in which the periprocte is placed, producing a beak- 



FROM THE UPPER GREENSAND. 299 

shaped projection at the superior part of the border where the two carinas meet above 
the vent as seen in profile in fig. 1 e. 

Affinities and Differences. — This species is well characterised by its large, deep, 
anteal sulcus, angular upon the sides, where it is sharply defined by its two carinas, and 
prolonged from the peristome below to the apical disc above by these boundary ridges 
arising from the folds of the test. These characters added to the height of the test 
with its angular circumference easily distinguish it from Cardiaster latissimus, and 
the same group of characters readily mark it out as a very distinct form from Cardiaster 
granulosus and C bisulcatus. 

Locality and Stratigrapliical Position. — This species has been collected only from the 
Upper Greensand of Wiltshire ; it was formerly an abundant fossil in these beds ; but has, 
however, now become scarce ; fine specimens with the test in good preservation are 
seldom found. The large shells I have figured belonged to Mr. Cannington's collection, 
and were collected many years ago. These grand specimens now belong to the British 
Museum. 



Cardiaster Perezii, Sismonda, 1843. PI. LXVIII, fig. 2 a, b, c. 

HoLASTER Perezii, Sismonda. Sugli Ech. Foss. di Nizza, p. 11, pi. i, figs. 1 — 3, 

1843. 

— — Agassi: and Desor. Catalogue Raisonn^ des Echinides, 

p. 135, 1847. 

— — Albin Gras. Oursins Fossiles de I'lsere, p. 62, 1848. 

— BISULCATUS, Albin Gras. Oursins Fossiles de I'lsere, p. 62, pi. iv, figs. 7, 

8, 1848. 

— Perezii, d'Orbigny. Prodrome, t. ii, p. 141, 1850. 

— — d!Orbigny. Paleont. Franfaise Ter. Cret., p. 86, pi. dcccxiii 

figs. 1—7, 1853. 
Cardiaster bisulcatus, Forbes. Mem. Geol. Surv., decade iv, pi. ix, Notes on 

Gardiasters, 1852. 
— — Morris. Catalogue of British Fossils, 2nd ed., p. 73, 1854. 

Holaster Perezii, Be Loriol. Echinid. Helvetique Ter. Cret., p. 325, pi. xxvii, 

figs. 6—8. 1873. 

Diagnosis. — Test convex, enlarged before, contracted behind, elevated anteriorly to 
the ambulacral summit, and gradually incHned from thence to the posterior border, 
anteal sulcus short, deeply indenting the anterior border, antero-lateral ambulacral 
narrowly lanceolate ; postero-lateral ambulacra short and wide ; posterior border 
accuminated and oblique, vent low down in a small truncated area, periprocte oval. 
Primary tubercles very small in proportion to the size of the test, a dorsal carina 
extending from the vertex to the border ; apical disc small, situate at the junction of the 
anterior, with the middle third of the upper surface. 



300 CARDIASTER 

Dimensions. — Antero-posterior diameter two inches and one tenth ; transverse diameter 
two inches ; lieight one inch and one tenth. 

Description. — In notes to a hst of British Cardiasters appended to a description of 
pi. ix, decade iv, of the ' Memoirs of the Geological Survey of the United Kingdom,' 
Professor Edward Forbes says, "in the Museum of Practical Geology there'is a Cardiaster 
from the Greensand of Blackdown, remarkable for the small tubercles in proportion to 
its size and the great width of the hinder lateral poriferous avenues. It seems to be 
identical with the Holaster hisulcatiis^ described and figured by M. Albin Gras in his 
' Oursins fossiles de I'lsere.' " I had a very careful drawing of this rare Urchin made 
from the type specimen, and placed it (fig. 2 a, h, c) on the same plate with C. fossarius, 
to show its near affinity with that form. 

The test is cordate, about as long as it is wide ; the anterior border is elevated 
(fig. 2 b) and deeply indented (fig. 2 a) by the anteal sulcus, which is well defined by the 
angular folds bounding the depression on both sides (fig. 2 c) ; the central portion of 
the ambulacrum is smooth and the pairs of pores minute and distinct from each other. 
The antero-lateral ambulacral pairs (fig. 2 a) are short, narrowly lanceolate, and the 
postero-lateral pair wider behind ; the poriferous zones of all the avenues are narrow, and 
their pores are small slit-like apertures. The ambulacral summit is near the anterior 
border of the junction of the anterior with the middle third of the test. The apical 
disc which occupies this point is small, compact, and formed of four perforated ovarial 
and five minute ocular plates. The surface of the plates carry very small tubercles in 
proportion to the size of the test, a well-marked character originally pointed out by 
Forbes. A few^ larger tubercles occupy the angles of the sulcus and anterior border, but 
on the other portions of the upper surface they are very uniformly diminutive. The 
posterior border much accuminated above (fig. 2 a) and obliquely truncated inwards 
below (fig. 2 b) ; the anal area is very limited, and the oval periprocte opens at the top 
of the oblique truncature of the posterior border. 

Affinities and differences. — Cardiaster Perezii resembles C. fossarius in many of its 
essential characters ; it difi'ers, however, in some minor points in the anatomy of its test ; 
the posterior half is much more accuminated, the anal area nuich smaller, the upper 
surface is likewise more inclined from the vertex of the border than in C. fossarius. The 
tubercles are smaller on the upper surface, but larger, and more developed at the base. 
The continental authorities as MM. d'Orbigny, Cotteau, and De Loriol, consider this 
Urchin as a true Holaster. In deference to the opinion of my lamented colleague 
Professor Edward Forbes I have left it in the genus in which he placed it. 

Locality and StratigrajjMcal Position. — This Urchin is very rare in England, and has 
been collected only from the Upper Greensand at Blackdown with Ec/nnos^jataffus Murcki- 
sonianiis. In France it is found in the Gault at Ravis (Isere), and at Clar near Escragnolle. 
In Switzerland, Perte-du-Rh6ne, Sainte-Croix (Vaud), Wannealp, Oberalp (Wsggithal), 
Cheville, Bossetan (Valais), and in France, near Nice. 



THE 



PALiEONTOGMPHICAL SOCIETY. 



INSTITUTED MDCCCXLVII. 



VOLUME FOE 1881. 



LONDON 

MDCCCIXXXI. 



MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODERMATA 



FBOM 



THE CRETACEOUS FORMATIONS. 




Br 

THOMAS WRIGHT, M.D., F.R.S., F.G.S., 

VICE-PRESIDENT OF THE PALjEONTOGRAPHlCAL SOCIETY; CORKESPONDING MEMBER OF THE EOYAl. SOCIETY 01' SCIENCES 

OF LIEGE; THE SOCIETY OF NATURAL SCIENCES OF NEUCHATEL; VICE-PRESIDENT OF THE COTTESWOLD 

naturalists' FIELD CLUB; CONSULTING SURGEON TO THE CHELTENHAM HOSPITAL; 

AND MEDICAL OFFICER OF HEALTH TO THE URBAN SANITARY DISTRICTS 

OF CHELTENHAM, CHARLTON KINGS, AND LECKHAMPTOK. 



VOLUME FIRST. 

PART NINTH. 
ON THE ECHINOCORID^. 

Pages 301—324 ; Plates LXX— LXXV. 



LONDON: 

PRINTED FOR THE PAL^ONTOGRAPHICAL SOCIETY. 

1881. 



PRINTED BY 
J. E. ADLAKD, BARTHOLOMEW CLOSE. 



PROM THE WHITE CHALK. 301 



Cardiaster pygMjEUs, Forbes. PI. LXIX, figs. 1 a — e. 

Cakdiaster PYGMiEUS, Forbes. Ann. Nat. Hist., 2nd ser., vol. vi, p. 444, 1830. 

— — Forbes. Mem. Geol. Surv., decade iv, pi. ix, notes, 1852. 

— — Morris. Catal. of Brit. Foss., 2nd ed., p. 73, 1854. 

Diagnosis. — Test very small, ovate, and cordate ; anterior channel large ; ambulacral 
areas wide, sparsely covered with microscopic tubercles ; posterior border truncated 
vertically ; periprocte in the upper third ; upper surface gently rounded, with an elevated 
carina between the apical disc and the upper margin of the periprocte. 

Dimensions. — A middle-sized specimen measured in the antero-posterior diameter 
half an inch ; in the transverse diameter five twelfths of an inch, and in height four 
twelfths of an inch. It is found, however, that the proportions vary considerably. 

Description. — This small Cardiaster is common in the Chalk at Dover, where many 
good specimens were collected several years ago by Major C. F. Cockburn, R.A., who 
kindly supplied examples for this work. The outline of the test is ovate, gently rounded 
on the upper surface (PL LXIX, figs. 1 d, e), and provided with a subcarinated ridge, 
which rises behind the apical disc (fig. 1 a), and extends backwards to the upper border 
of the periprocte (fig. 1 d). The anteal sulcus is wide (figs. 1 a, e) and strongly 
carinated, and the posterior border is sharply truncated (fig. 1 c) ; the oval periprocte 
opens in the upper third (fig. I d) ; the sides of the test are moderately inflated (figs. 1 e 
and 1 c), and the view from the base shows the ovato-cordate ambitus of this beautiful 
little Urchin (fig. 1 b). 

The ambulacral areas are acutely lanceolate on the upper surface, the antero-lateral 
curve a little backwards, and the postero-lateral pass direct to the disc ; the poriferous 
avenues are very narrow, and the pores in single pairs are set closely together. 

The surface of the test appears to be perfectly smooth. When examined with a lens, 
however, it is seen to be covered with minute granules, among which a number of 
primary tubercles of small size are scattered (fig. 1 a, b, c). 

The base is flat at the sides, and has a central elevated ridge, which extends from 
the pei'istome to the posterior border (fig. \ c, b) ; the mouth is transversely oblong, 
and situated near the anterior border (fig. 1 b). 

Affinities and Differences. — This Urchin when magnified two diameters, as it is in our 
figures, has a striking resemblance to Holaster Icevis ; but diS"ers in having the anteal 
sulcus deeper and wider, its sides more angular, and the posterior border broader and 
more sharply truncated than in that species ; the mouth is also nearer the anterior border. 

Locality and StratigrajiUical Position. — This small Urchin has hitherto been found 
only in the Upper White Chalk at Dover, Kent, and was first briefly noted by the late 
Prof. Edw. Porbes, E.R.S., in the ' Ann. and Mag. of Nat. History,' 2nd series, December, 
1850. 

39 



302 CARDIASTER. 



Cardiasteb ananchytis,! Leske. PL LXIX, figs. 2 a — i, 3. 

Spatangus ananchytis, Leshe. Addit. ad Kleinii Echin., p. 243, pi. liii, figs. 1, 2, 

1778. 
Echinus ananchytis, Gmelin. Sytema Naturae, p. 3199, No. 97, 1789. 

— — Encycloped. Mt'th., Melius, et Zoopb., Atlas, pi. clvii, 

figs. 7—10, 1791. 
Ananchytes cordata, Lamai-ck. Anim. sans vertfebres, t. iii, p. 26, No. 8, 1816. 
Spatangus granulosus, Goldfuss. Petref. Germanise, p. 148, pi. xlv, fig. 3, 1826. 

— — Desmotilins. Etudes des Ecbinides, p. 410, 1835. 

— coEDiFORMis, TFoochvard. Geol. of Norfolk, p. 50, pi. v, fig. 6, 1833. 
HoLASTER granulosus, Agassiz. Prodrome, p. 16, 1836. 

— — Agassi: Sf Desor. Cat. Rais. des Ecbinides, iu Ann. des 

Sc. Nat., 3rd. ser., vol. viii, p. 27, 1847. 

— JEQUALis, PortlocJt. Geol. Rep. Londonderry, p. 355, pi. xvii, 1843. 

— coRDiroRMis, Forbes. Ann. Nat. Hist., 2nd ser., vol. vi, p. 443, 1850. 
Caediastek GRANULOSUS, Forbes. Mem. of the Geol. Survey, decade iv, pi. ix, 1852. 

— ANANCHYTIS, d'Orhigny. Paleont. rran5. terr. Cretnces, t. vi, p. 131, pi. 

826, 1853. 

— GKANULosus, Forbes. Morris Ciital. of Brit. Foss., 2nd ed., p. 73, 1854. 

— ANANCHYTIS, Besor. Synops. des Ecbin. Foss., p. 345, pi. xxxix, figs. 

7—9, 1857. 

— — Coqxiand. Bull. Soc. Geol. France, 2e ser., torn, xvi, 

p. 1010, 1860. 

— — Cotteau. Ecbinides du Dep. de la Sartbe, p. 237, pi. li, 

fig. 2—5, 1860. 

— GRANULOSUS, Schluter. Foss. Ecbinoderm. des nordlicben Deutscblands 

Verb. d. Nat. Vereinsder Rbeinl. und Westpbal., Jabrg. 
xxvi, Folge iii, Band vi, p. 251, 1869. 

Diagnosis. — Test regularly cordate ; upper surface iu one variety depressed, in 
another more elevated. Primary tubercles large and conspicuous on each side of the 
anteal sulcus, which is wide and deep ; posterior border narrow and obliquely truncated. 

Dimensions. — This Urchin grows to a considerable size. The fine figured specimen 
is two inches and seven tenths of an inch in length, two inches and four tenths of an inch 
in breadth across the widest part of the ambitus, and one inch and four tenths of an inch 
in height at the vertex. Other specimens have greater height in proportion to their 
breadth, or greater length in proportion to their width, and others are higher and more 
convex on the upper surface, or are flatter and more depressed throughout. 

The French specimens collected in the Sarthe, according to Mons. Cotteau, vary 
much in their proportional dimension. Far. major. — Antero-posterior diameter 43 milli- 
1 Termed in error Cardiaster granulosus on tbe explanation of figs. 2 and 3, Plate LXIX. 



FROM THE WPIITE CHALK. 303 

metres ; transverse diameter 42 millimetres ; height 26 millimetres. Far. minor. — 
Antero-posterior diameter 27 millimetres; transverse diameter 25 ; height 15. 

Description. — This elegant Urchin has a regularly cordate ambitus. It is deeply 
channelled in front by the anteal sulcus, which has sloping walls, with angulated borders 
above, and a deep granulated channel below. The greatest breadth of the test is 
immediately behind the antero-lateral ambulacra ; from this point it slopes gently 
towards the posterior border, which is very narrow, and slightly truncated downwards 
and inwards. 

The upper surface is convex, very much rounded before, and declining gently behind. 
The imder surface is very much depressed near the mouthy and slightly convex in the 
single inter-ambulacrum, which has a sinuous ridge along the middle line, with nodular 
elevations at each alternate angle. The vertex is nearly central. The anteal sulcus is 
deeply hollowed out from the summit to the mouth, especially at the ambitus, and is 
circumscribed laterally and superiorly by angulated carina:. The single ambulacrum is 
lodged in the sulcus, and composed of very small round pores, separated by a granuliform 
elevation, and situated in a small, smooth, lanceolate fossa, very narrow above and 
expanded below. The pores are close together above, and widen as the plates become 
larger. There are about twenty-eight plates visible in a full-grown specimen. The 
antero-lateral ambulacra are subpetaloid in their upper part, and unsymmetrical, in 
consequence of the pores of each pair being wider apart in the outer row than in the 
inner, and, moreover, being united by a deeper groove. There are about twenty-four 
pairs of pores in the subpetaloidal portion. They are closely approximated, and those 
that are below widen out ; the outer series is likewise slightly arcuated. In the postero- 
lateral ambulacra the two series arc nearly similar, and there are about eighteen pairs of 
pores in the subpetaloid portion. There are about nine plates in each series in the 
dorsal portion of the lateral inter-ambulacral segments, and ten above the vent in the 
posterior segment. The infra-anal portion of the latter is composed of two series of five 
irregularly polygonal plates each. They are remarkable for presenting gibbosities at 
regular intervals. In the inferior portions of each postero-lateral ambulacrum there are 
seven plates in each series. These are polygonal, large, and elongated, and bear the 
pairs of pores, which are minute and oblique, close to their inner angles. The pores of 
the ambulacra around the mouth form an obscure star. 

The surface of the plates is profusely covered with very fine granules, which observe 
a very regular arrangement among them. Two sets of tubercles of unequal size cover 
the plates at regular distances apart ; the small tubercles, which are seated among the 
granules of the upper surface (fig. 2/), and the large tubercles, which arc perforated and 
crenulated, are seen on the upper surface around the apical disc, upon the middle of the 
single inter-ambulacrum, and upon the borders of the anteal sulcus (fig. 2 e). In the in- 
fra-marginal region and along the central space on each side of the sinuous ridge (fig, 2 b), 
they arc large and conspicuous. Each of the large tubercles is elevated upon a boss 



304 CARDIASTER. 

with a ci-enulated summit, on which is placed a perforated tubercle (fig. 2 /). Very- 
fine, close-set, homogeneous granules are prolonged horizontally between the pairs of 
pores in the poriferous zones, and likewise fill up the anteal sulcus, which is completely 
deprived of primary tubercles (fig. 2 e and d). 

The apical disc is narrow, solid, and elongated, and so closely covered with the small 
granules that its elements are concealed. In many specimens it is composed of four 
ovarial and five perforated ocular plates. The anterior ovarials are small, and the madre- 
poriform tubercle is (juite rudimentary. The postero-laterals are long, and separated 
from the antero-laterals by two perforated oculars, so that the three anterior ambulacra 
are rather widely separated from the two posterior ambulacra (fig. 2 ^). 

The vent opens very low down in the narrow, posterior, triangular border. The 
periprocte is widely oval, and surrounded by numerous small granules (fig. 2 d). 

The marginal fasciole is more or less distinct in different specimens. It passes under 
the periprocte, and runs out upon the sides towards the convex portion of the ambitus. 
It is narrow, and free from intermingled tubercles (fig. 2 (j), and it is only well seen in 
very good specimens. 

The base is flat, and the mouth situated near the anterior border in a depression 
formed by the deep grooving of the anteal sulcus, where it turns round the anterior 
border (fig. 2 h, e). The peristome consists of a convex upper lip and a prominent under 
iip. A few tubercles make a radiate ornamentation about the upper lip (fig. 2 h). 

Jpiities and Differences. — Cardiasfer cinanchjtis is well distinguished from its 
congeners by its cordiform outline dilated before and subangular behind, by its deep 
anteal sulcus deprived of tubercles, by the poriferous zones very unequal in the antero- 
and postero-lateral pairs, by the large tubercles which show themselves sparsely on the 
upper surface, and by the low position of the periprocte. 

History. — Leske (1778) first figured an imperfect specimen of this Urchin under the 
name of Spaiangm anavcliyfls, and Lamarck afterwards called it Ananchytes cordafa. 
Goldfuss figured it under the name of Spafavytis yranulosus, and S. orbicularis. Mr. 
Samuel Woodward, in his 'Geology of Norfolk,' ^guveA it a^ SpafangHs cordiformis ; 
and then succeeded the various changes of name which have been already noted in the 
synonymy of the species. It is, however, to M. d'Orbigny's quick perception that we are 
indebted for first identifying Leske's figure with the subject of this article. 

Locality and StratigrapJdcal Position.— First identified as a British Urchin by 
Mr. S. Woodward, who stated that it was rare in the Upper Chalk at Harford Bridge, 
and common in the Medial Chalk at Swaff"ham and Thetford, Norfolk. General 
Portlock has found and described it as Rolaster cequalis in the Chalk of Londonderry. 

Foreign Localities. — It has been collected in France, where it is rare, at Chateau-du- 
Loir, Teiffe, Duneau, Villedieu, Sarthe ; Tours, Indre-et-Loire ; Lauquais, Dordogne ; 
Meudon, Seine : at Ciply, Belgium ; Langelsheim, Brunswick ; Haldem, Westphaha, in 
North Germany: it is found in the Upper and Lower Senonian. 



INFULASTER. 305 



Genus — Infulaster, Hayenow MSS., 1851. 

Caediastek, Forbes. 1852. 

Infulaster, JDesor (with diagnosis). 1858. 

ZITTEL. 1879. 

Test narrow, oblong, of an irregular ovato-cordate form. Anterior half very much 
elevated, rising into a prominent vertex, situated nearly above the anterior border ; the 
anteal sulcus narrow, deep, and directed obliquely downwards and backwards, with two 
prominent angular borders, which rise above the upper surface. Plates smooth, covered 
with very small granules ; a few primary tubercles near the vertex and at the sides, and in 
the centre of the under surface ; a sub-anal fasciole is seen only on some fine specimens. 



Infulaster excentricus. Hose. PI. LXX, fig. 1, a — /•. 

Spatangus excentricus. Rose. Woodwai-d's Geo), of Norfolk, p. 27, pi. i, fig. 5, 

1833. 
Cardiasteb excentricus, Forbes. Ann. Nat. Hist., 2nd series, vol. vi, p. 443, 1850. 

— — Forbes. Mem. of Geol. Surv., decade iv, pi. x, 1852. 

— — Morris. Catal. of Brit. Foss., 2nd ed., p. 73, 1854. 

Diagnosis. — Test long, ovato-cordate ; upper surface considerably elevated anteriorly 
and declining much to the posterior border ; anteal sulcus deep, narrow subvertical ; 
vertex very excentric ; posterior border obliquely truncated, forming a triangular space, in 
which the periprocte occupies the upper angle. 

Dimensions. — Antero-posterior diameter one inch and eight tenths of an inch ; 
transverse diameter one inch and four tenths of an inch ; height one inch and three 
tenths of an inch. These are the measurements of the large specimen figured in PI. 
LXX, most kindly given to me by my friend the late Mr. Rose many years ago for this 
work. 

De.scrij)fiofis. — This singular Urchin has long been one of the greatest rarities of the 
Norfolk Chalk. When viewed in profile it presents the singular form seen in PI. LXX, 
fig. 1 c ; the high vertex nearly overhangs the anterior border, and the upper surface 
slopes away at an angle of 30° towards the posterior border which is truncated obliquely 
downwards and outwards, and imparts another odd feature to the test. 



306 INFULASTER. 

The dorsal surface is very high anteriorly (fig. 1 c), and the walls of the anteal sulcus 
rise nearly perpendicularly to the highest part of the body (fig. 1 d, e) immediately in 
front of the apical disc (fig. 1 a). From the point of its greatest elevation the upper 
surface gradually declines nearly in a straight line (fig. 1 c, i), forming a long sub-carinated 
ridge, which extends to the upper part of the posterior border (fig. 1 d), at about half the 
heio-ht of the test at the vertex. On each side of the ridge the upper surface slopes 
away rapidly (fig. 1 d), but the sides are rounded, and, in the antero-lateral regions, 
tumid (fig. 1 e). The posterior border forms a triangular space (fig. 1 c, d, i) ; which is 
obliquely truncated, and has the periprocte opening in its upper angle surrounded by a 
circle of tubercles two rows deep (fig. 1 d). 

The under surface is convex in the antero-posterior, and transverse diameters, so that 
the under surface of the body is gently rounded in all directions ; on the cheeks at the 
base a few primary tubercles are observed (fig. 1 ^), and on the plastron another grouping 
of like tubercles is placed. 

The single ambulacrum is lodged in the deep anteal sulcus, but the poriferous zones 
are scarcely discernible in good specimens. The lower half of the depression is rounded 
and covered with minute granules, among whicli no indications of pores can be seen with 
a hand magnifier; in the upper third they are small, indistinct, and closely set together, and 
are best seen where the uppermost portion of the area curves backward to meet the apical 
disc (fig. 1 a, c). Here we see a few pairs of small round pores, arranged in a vertical series, 
and the single ambulacrum articulating with the disc a httle in advance of the antero-lateral 
ambulacra ; these are placed very far forward and extend over the most tumid part of the 
sides of the test (fig. 1 c and i). The pores are very small (fig. 1 a). Forbes counted on 
a large specimen thirty pairs of pores in these rows between the apex and the margin ; 
in my figured specimens only twenty can be identified. The avenues or poriferous zones 
are at the surface of the test, and the pairs of pores of the outer rows are a little 
wider than the inner one. The postero-lateral ambulacra are even less conspicuous 
(fig. 1 c,d) ; they diverge greatly from the antero-laterals, and form together a very acute 
angle. Their uppermost portion consisting of closely-set pores. On their posterior 
portions the pairs of pores become very indistinct. 

The apical disc is small, narrow, and elongated (fig. 1 /^). There are four perforated 
ovarial plates in the middle, and five very small perforated ocular plates at the summits 
of the areas ; all the parts of the disc are very solid and firmly joined into the other 
elements of the test. 

The mouth is situated near the anterior border (fig. 1 It) at the point wliere the 
anteal sulcus terminates, it therefore lies in a depression. It is a small opening with a 
round or transversely oblong peristome ; the anterior lip is smooth, and the posterior 
more developed. 

The vent is situated in the upper third of the truncated posterior border (fig. 1 d). 
The periprocte is vertically oval and of large size (fig. Id); its upper half is surmounted 



FROM THE WHITE CHALK. 307 

by an arch of small tubercles, three tiers or more in depth, whilst the lower surface 
of the border is closely covered with small granules, among which a few small tubercles 
scattered here and there are seen. 

The body-plates of the test are throughout covered with very fine close-set granules, 
and amongst these several small tubercles are disposed, from six to nine on each plate ; at 
fig. 1 /, eight plates from the sides of the test have been carefully drawn and enlarged 
three diameters ; in order that this arrangement on their surface, which is clearly demon- 
strable in good specimens, may be shewn, for on these only can the structure be 
discerned. 

The plates on the margins of the anteal sulcus are thickly studded with large 
primary tubercles (fig. 1 c, e), which are raised on bosses with crcnulated summits, and 
surmounted by perforated tubercles (fig. 1 (/). The areolae around the bosses are 
encircled by granules ; tubercles similar to these in form and structure are seen on the 
cheeks of the shell, and a few are extended along the sides and on the central plates of 
the rounded base (fig. 1 h). 

Forbes described the fasciole as " distinctly marked, passing under the vent and 
continued on each side, even over the cheeks." Some indications of this fasciolar track 
were drawn by my artist, who noted his impression in fig. 1 h ,- but I have seen nothing 
that I would call a fasciole, such as we observe in Hemiasters, Micrasters, &c., in any of 
the forms that have come under my examination. 

Localily and StratigrapMcal Position. — This remarkable Urchin, with which I know 
nothing to compare, was first observed by my old friend Mr. C. B. Rose, of Swaffham, 
and communicated by him to Mr. Samuel Woodward, in whose ' Geology of Norfolk ' it 
was first figured from specimens collected from the Upper and Medial Chalk of Norfolk. 

Affinities and Differences. — Infalastcr excentricus. Rose, very much resembles Infulaster 
Hagenoioi, Borchards, collected from the White Chalk of Staffin, in the Island of 
Wollin, Pomerauia. A model in wax was communicated to Professor d'Orbigny by Herr 
von Hagenow, in 1851, without any other indication of publication. A comparison of 
specimens would alone enable the observer to decide on the affinities and differences of 
the German as compared with the Norfolk form ; seeing that one of the specimens given 
me by Mr. Rose very much resembles Infulaster Hagenoioi, Borchards. 



Infulaster rostratus, Forbes. PI. LXX, figs. 2, a—f; 3 a. 

Diagnosis. — Test much compressed on the sides ; anteal sulcus long, deep, and 
narrow, its sides rising high into a beak ; dorsal surface curved and carinated ; posterior 
border obliquely truncated, bent in upper third ; sub-anal fasciole, well defined, and 
extended on the flanks. 



308 INFULASTER. 

As I have been able to obtain only fragments of this Urchin, too imperfect for 
description, I shall transcribe the account which my late esteemed colleague Professor 
Edward Forbes, F.R.S., gave of it in the ' Memoirs of the Geological Survey ' decade iv, 
p. 3, 1852. 

" For some time," says Forbes, " I was under the impression that this extraordinary 
and anomalous little Urchin, of which specimens were kindly communicated by Dr. Bower- 
bank, Mr. Wetherell, and ]\Ir. Woodward, was the young of the CarcUasfer excenfricus, 
different as its outline is. The series of specimens of various sizes of the latter shown me 
by Mr. Rose convinces me that it is necessary to regard this beaked and iVe<?ra-like form 
of Cardiaster as distinct. All the examples are impressed with the same peculiarities. 
The number submitted to me has been seven, including fragments ; and in addition to 
those lent for examination are two fine specimens, one of them nearly entire, found by 
Mr. Cockburn, in the Chalk-with-Flints, at Bostal Heath, near Plumstead, and generously 
presented by that gentlemen to the Museum of Practical Geology. 

" The striking feature of this form is the rhomboidal profile which it exhibits in conse- 
quence of the obliquity of the anteal and posteal truncations, both inclining forwards at 
considerable angles (fig. 2 a — e). The anteal ambulacral sulcus is very deep, long, and 
narrow ; it rises obliquely to a great height in consequence of the elevation of the apical 
disk upon a sort of beak (fig. 2 e). The genital plates are assembled just below its summit, 
which is notched by the turning over, as it were, of the anteal furrow. The details of 
the lateral ambulacra, in consequence of their being completely plane and very obscure, 
can with difficulty be distinguished ; the rostrum bends forward slightly in its upper 
part. The summit of the back is more or less sharply carinated, and declines rapidly with 
a faint concave curve, until it terminates in the summit of the very oblique and rapidly 
declining posterior truncation, in the uppermost part of which, at rather less than the 
total height of the body, is the anus, placed at one end of a groove. The whole of the 
dorsal surface of the test is covered with granules interspersed with scattered minute 
tubercles, which become more numerous on the slightly tumid cheeks. The fasciole is 
strongly and distinctly marked, and passes from beneath the anus over the cheeks. 
The base is flattened, and except on the ambulacral spaces is strongly tuberculated. 
The mouth is very small and far forward." 

Dimensions. — The largest specimen measured in length at the base, eight twelfths of 
an inch ; in breadth, six twelfths of an inch ; and in height, ten twelfths of an inch at 
the anteal sulcus. 

Locality and Strati^rapJdcal Position. — In the Chalk-with-Flints of Kent and 
Norfolk. 



HOLASTER. 309 



Gemis — HoLASTER, Agassiz, 1839. 
Synonym — Spatangus, Anct. 

The test has an oval or corcliform figure, more or less convex at the upper surface, 
and, in general, flat at the under surface. 

The pairs of antero- and postero-lateral ambulacral areas are apetaloidal, superficial, 
and lanceolate ; they are widely apart below, and join each other above. 

The poriferous zones are formed of elongated pores (always those in the external 
rows), disposed by simple pairs, very much separated and regularly superposed on each 
other, between the ambitus and apical disc. The ambulacrum, or single anterior 
area, is always lodged in a shallow central sulcus ; its pores are very minute and 
resemble those of the lateral areas. The ambulacral summit is central or subcentral. 

The apical disc is solid and elongated ; its elements consist of four perforated ovarial 
plates and five perforated oculars. The genital plates arc disposed in pairs, and the 
anterior are separated from the posterior pair by a pair of ocular plates being interposed 
between them. 

The posterior border is narrow and more or less truncated, and the periprocte, 
always marginal, opens in general in the upper part of this region. The mouth-opening 
is situated near the anterior border in a slight depression, and the peristome is trans- 
versely oval and imperfectly bilabiate. There are no fascioles on any part of the test. 

The shell is very thin, and the surface of the plates is uniformly covered with a very 
fine granulation ; tubercles, more or less developed, appear in irregular order among 
them. Granules attaining their largest size, in the form of tubercles, appear upon the 
plates of the inter-ambulacral areas, and on those of the basal region, and this is more 
especially so in Holaster Trecensis, Leym. The ambulacral areas have, however, fewer 
tubercles than the other areas. The Holasters appertain to the Cretaceous Rocks, and 
form leading fossils in certain stages of the same ; they are most abundant in the Upper 
Greensand and Lower Clialk, one species only being special to the Wliite Chalk. 

There seems to have been an unnecessary amount of confusion in the synonymy of 
some of the species, arising it would appear more from the copying of names than 
from the inspection and comparison of the specimens themselves. 

In the British Islands we find : Holaster lavis, De Luc, in the Upper Greensand 
and Lower Chalk ; Holaster obliquus, Wright, in the Upper Greensand and Lower 
Chalk ; Holaster suhorhioilaris, Dcfrance, in the Chloritic Marl and Lower Chalk ; 
Holaster Icevls, var. planus, Mant., in the Upper Greensand, Lower Chalk, and lower 
portion of Upper Chalk ; Holaster subglobosm, Leskc, in the Chloritic Marl and Lower 
Chalk ; Holaster Trecensis, Leym., in the Lower Chalk ; Holaster pillula, Lamk., in the 
Upper Chalk. 

40 



310 



HOLASTER 



HoLASTER L;Evis, Be Luc. PI. LXXII, fig. 1 a — -f. 



Spatangus l^vis, 
Ananchytis caeinata, 
Spatangus l^vis, 

nodulosus, 



HoLASTER LiEVIS, 



TEANSVERSUS, 
StrB0KBICULARIS,^^as«(5^. 

Sandoz, Agassiz. 

LiEVis, Agassis. 

KODDLOSTJs, Agassiz. 
SUBOEBICULABIS, Agassiz. 

NODULOSUS, 

PLANUS, 
LiEVIS, 

TEANSVERSUS, 
CAEINATUS, 

L.iEVIS, 



CARINATUS, 

L^VIS, 



— CAEINATUS, 



L^VIS, 



De Luc. Cat. Collection, Berne Mus. 

Lamarck. Aniinau.x sans Vertebres, t. iii, p. 26, 1816. 

Brongniart. Descr. Geol. des Environs de Paris, pp. 97 et 

399, pi. ix, fig. 12, 1822. 
Goldfuss. Petref. Germanic, Band i, p. 149, pi. xlv, fig. 6, 

1826. 
Blainville. Manuel Actinologie, p. 204, 1834. 
Desmoulins. Etudes sur les Echinides, p. 410, 1837. 
Agassiz. Descr. des Echinid. Suisses, t. i, p. 17, pi. iii, figs. 

1—3, 1839. 
Agassiz. Ibid., t. i, p. 18, pi. iii, figs. 4 — 5, 1839. 
Ibid., t. i, p. 21, pi. iii, figs. 11— 13, 1839. 
Ibid., t. i, p. 11, pi. ii, figs. 1—3, 1839. 
Catal. Ectyp. foss. Mus. Neoc, p. 1, 1840. 
Ibid. 
Ibid. 
Morris. Catal. of British Fossils, p. 54, 1843. 
Morris. Ibid., p. 54, 1843. 
Morris. Ibid., p. 54, 1843. 
d'Orbigny. Paleont. Fran^., Ter. Cret., t. vi,p. 83, pi. 812, 

1853. 
(TOrbigny. Ibid., p. 88, pi. 819, 1853. 
d'Orbigny. Ibid., p. 104, pi. 818, 1853. 
Renevier. Mem. Geol. sur la Perte-du-Rhone, p. 49, 1855. 
Pictet. Traite de Paleontologie, 2nd ed., t. iv, p. 192, 

pi. xciii, fig. 3, 1857. 
Pictet. Ibid., t. iv, p. 192, 1857. 
Desor. Synopsis, p. 339, 1858. 
Lory. Descr. Geol. du Dauphin^ p. 339, 1860. 
Lory. Ibid., p. 350, 1860. 
Cotteau. Echinides de la Sarthe, p. 195, pi. xxi, figs. 3 — 

5, 1860. 
Cotteau. Echinides Foss. de I'Yonne, t. ii, p. 249, pi. kix, 

figs. 6, 7, 1865. 
Geinitz. Elbthalgebirge in Sachsen i, p. 84, pi. xx, fig. 5, 

1871. 
Be Loriol. Echinol. Helvetique Ter. Cret., p. 319, pi. 

xxvii, figs. 1 — 5, 1873. 



Diapiosis. — Test oval, cordiforiu, slightly grooved before, and narrowed a little 
behind ; largest diameter in the middle of the postero-lateral inter-ambulacra. Upper 
surface in general depressed, sometimes elevated and convex. The middle of the single 



FROM THE UPPER GREENS AND. 311 

inter-ambulacrum (occasionally only) more or less elevated into a carina ; under surface 
flat ; peristome near the anterior border. Periprocte oval, situated in the upper part of 
a small truncated posterior border. Ambulacral summit subcentral, a little nearer the 
anterior border. 

Bimensions. — Antero-posterior diameter one inch and a half; transverse diameter 
one inch and four tenths; height eight tenths of an inch. These are the dimensions 
of the average number of adult specimens obtained from the Upper Greensand of 
Wiltshire. 

Description. — The body of this Urchin has a very regular figure, of a cordato-ovate 
shape, larger before and tapering behind, the largest transverse diameter being across 
the middle of the postero-lateral inter-ambulacra. The anteal sulcus is very shallow, 
and the anterior border only slightly depressed; the posterior border is narrow and 
obliquely truncated a little downwards and inwards. 

The upper surface is in general elevated and convex (PI. LXXII, fig. 1 b, c, d, e), 
and some specimens have the posterior half of the test a little more ridged, and the 
middle line forming a blunt carina, which has been erroneously considered a specific 
character by several authors (fig. 1 c, d). 

The ambulacral areas are wide, apetaloid, and disjoined at the summit ; the antero- 
lateral pair are arched backwards and forwards in their upper thirds (fig. 1 d), and the 
postero-lateral pairs slightly bent in the opposite direction (fig. 1 d) . The single ambulacrum 
(fig. 1 6, e) is lodged in a wide, shallow anteal sulcus, the depression from which vanishes 
in the upper half of its length (fig. 1 e), so that the convexity of the dorsal surface is 
almost complete (fig. 1 b). The poriferous zones are narrow, the pores small, closely 
set in pairs, placed near each other above, and wider apart as they descend the sides. 
At the under surface the ambulacral areas are large and smooth, and quite superficial. 
The pores in the single ambulacrum are extremely small, and seen only in very good 
specimens. 

The apical disc is narrow and elongated (fig. 1 b). The genital plates, four in 
number ; are arranged in pairs, and between the anterior and posterior pairs one pair of 
the five ocnlar plates is interposed by aposition of the discal elements. The apices of the 
ambulacral areas are disjoined, as seen in fig. 1 b. 

The base is very flat (fig. 1 a), and the ambital border forms an acute angle. The 
mouth-opening is lodged near the anterior border, in a depression of the test formed by 
the arching round the angle of the anteal sulcus. The peristome has an oval figure, 
slightly elongated transversely. 

The vent opens at the posterior truncated border, always low down, near the base 
(fig. 1 d). The anal area is a very small, slightly hollowed-out space, the periprocte is 
oval in a vertical direction, and has a well-defined border. 

The surface of all the plates is covered with an extremely fine abundant micro- 
scopic granulation, which is preserved in patches on diff"erent parts of good specimens; 



312 HOL ASTER 

in those from the Upper Greensaud it has entirely disappeared, whilst on some speci- 
mens from the Lower Grey Chalk and the Chloritic Marl, its true character may be 
studied. Fig. 1/ shows an enlarged portion of a test, in which the granules existed 
with several of the primary tubercles interspersed at irregular intervals in the midst of 
the granulation. Many of the tubercles are raised on finely crenulated bosses, which 
support small perforated tubercles, accurately drawn in fig. 1/. 

Affinities and Differences. — The general form of the test varies much in this species, 
being more or less depressed or elevated in different examples ; still the other characters, 
which may be considered as specific, remain very permanent in all these variations. The 
examples collected from the Grey Chalk near Folkestone, and from the Lower Chalk of 
Sussex, are in general larger and better preserved than the small typical specimens 
collected from the Upper Greensand at Chute Farm, Wilts. The Chalk specimens have 
likewise retained many of the large primary tubercles surrounded by patches of the 
granulated surface, and specimens collected from our Lower Chalk are absolutely 
identical with a specimen I have from the Craie Chloritee of Cap-le-Heve, near Rouen. 

After a careful comparison between the tests of Hoi. IcBvis and those of Hoi. 
carinatus, and good figures of Hoi. transversus and Hoi. marffinatus, I agree with my 
learned friend, Monsieur De Loriol,^ that they in reality are all so many varieties of Hoi. 
Icevis, grown under different physical conditions, which have changed only some of the 
external characters of their original form, but left the essential and specific ones 
untouched. De Loriol has examined likewise the original example of the true large Hoi. 
Sandoz, Agass., contained in the Museum of Zurich, with other examples of the collection 
of Monsieur Du Bois de Montpereux, found by him in the Upper Greensand of Souaillon 
(Neuchatel), and De Loriol affirms that Hoi. Sandoz is only a very large and very fine 
specimen of Hoi. Iccvis. Mons. De Loriol unites also Hoi. Trecensis, Leymerie, with 
Hoi. Icevis. In PI. LXXIV, fig. 2, I have given a very good figure of this species, and 
in page 324 have entered fully into this subject when describing its affinities. Holaster 
IcBvis differs from Hoi. planus, Mantell, in some particulars. Li Hoi. planus the test is 
larger, more oblong and less cordate, and the ambulacral summit subcentral nearer the 
anterior border ; the upper surface is flat and declines very little towards the posterior 
border, which is only slightly truncated to form an anal area, in the upper part of which 
the vent opens. Hoi. Icevis resembles likewise Hoi. suhorbieularis in some points of 
structure, but differs so widely in others that I must refer to my article on that species, 
and to that on Hoi. subglohosus, for the affinities and differences existing between them. 

Locality and StratiyrapJiical Position. — The small figured specimen I collected 
from the Upper Greensand at Chute Farm, Wilts, where it is very common. The 
tests are so much covered over with adhering sand particles that it is rare to obtain a 
good specimen. I have collected this species likewise from the Grey Chalk near Folke- 
stone, and from the Lower Chalk, near Lewes, Sussex, 

1 ' Echinologie Helvetique,' p. 324, 1873. 



FROM THE UPPER GREENSAND. 313 



HoLASTER OBLiQUUS, Hov. sp., Wright. PI. LXXVIII, fig. \,a — e. 

Diagnosis. — Test oblong, slightly cordate, greatest width across the anterior third, 
gradually diminishing in size to the posterior border, which is narrow and obliquely 
truncated; ambulacral summit excentral near the junction of the anterior with the 
middle third, upper surface convex and sloping downwards to the posterior margin ; 
anal opening in the upper part ; periprocte elliptical ; area narrow and inclined downwards 
and inwards. Base rounded ; raouth-opening near the anterior border ; anteal sulcus 
shallow and inclined downwards and inwards ; peristome small, transversely oval, 
unilabiate, and situated in a depression. 

Bimensiotis. — Antero-posterior diameter two inches ; transverse diameter one inch 
and three tenths ; vent above the base seven tenths of an inch. 

Description. — This rare Urchin has an oval outline ; its greatest width is posterior to 
the antero-lateral ambulacral areas. From this part of the ambitus it tapers obliquely 
inwards towards the narrow posterior border. The upper surface is convex and the 
ventral summit, near the apical disc, is situated about the junction of the anterior 
with the middle third, and to this point all the ambulacral areas converge ; from 
the disc to the posterior border the upper surface inclines obliquely downwards and 
forms a long slope towards the anal area. The antero-lateral ambulacra are short, 
straight, apetaloid, and lanceolate, and pass straight upwards from the ambitus to the 
disc. The postero-lateral ambulacra are straight, lanceolate, and apetaloid ; they are 
much larger than the anterior pair from the excentral position of the summit. The 
poriferous zones are narrow and superficial; the pores small, and placed in pairs ; forty 
pairs exist between the disc and the ambitus, and below that line they become invisible. 

The apical disc is a small, narrow, oblong body, of which the elements are so 
closely soldered together that the sutures are obliterated. 

The mouth-opening is small, and situated at a short distance from the anterior 
border in a depression formed by the incurving of the anteal sulcus. The peristome 
is small and transversely oval, and is placed near the junction of the first with the second 
fourth part of the total basal length of the shell. 

The vent opens in the upper part of the posterior border ; the anal area is very 
narrow, and the oval periprocte is situated high up in this space, where the convex portion 
of the long, obliquely-sloped back bends over the truncated portion of the posterior 
border. 

The surface of the plates is covered with a close-set miliary granulation, which is 
beautifully preserved in a specimen from the Upper Greensand of Wiltshire. On the 
larger plates a few small tubercles are developed without much order in their arrange- 
ment. Six to eight such tubercles are seen upon many of these plates. 



314 HOLASTER 

Affmiiies and Differences. — This species resembles, in many traits of structure, 
Holaster IcBvis. It is readily distinguished from that species by the ambulacral summit 
being much more ex central, which occasions a much longer slope between the apical 
disc and the posterior border, and a greater obliquity of the upper surface of the test ; 
the antero-lateral ambulacra are shorter and straighter, and the postero-lateral pair 
much longer. The anteal sulcus is likewise shallower, and the posterior border much 
narrower. The rotundity and smoothness of the test, and the width and shallowness of 
the anteal sulcus form a marked difference between it and Holaster suborbicularis, and 
the same characters serve to separate it very distinctly from Holaster suhglohosus. 

Locality and Stratiffrapldcal Position. — This Urchin appears to be rare. I have only 
seen three specimens ; two of these were collected from the Lower Chalk near Folkestone, 
and the third was obtained from the Upper Greensand at Chute Farm, near Warminster, 
Wilts, I have compared this Urchin with a large number of Holasters from the Chalk 
of France and Switzerland, in the cabinet of my friend M, De Loriol; and it is 
easily distinguished from all its congeners by the excentral position of the apical 
summit, and the long sloping declension of the posterior two thirds of the upper surface. 
The specific name excentricus was at first suggested for this species, but as we have the 
T/ifulaster excentricus from the Cretaceous Rocks it was better to adopt ohliquns as 
indicative of the obliquity of the upper and posterior surfaces of the test, in order to avoid 
any confusion regarding this new form, which I have now described and figured for the 
first time. 



Holaster suborbicularis, Defrance. PI. LXXIV, figs. 1 a — e. 

Spatangus suBOKBicuLAEis, De/>w2ce. MS., 1821. 

— — Brongniart. Descrip. geol. Paris, p. 85, pi. v, fig. 5, 

1822. 

— — Blainville. Mem. d'Actinologie, p. 204, 1834. 
HoLASTEK — Agassi::. Prodrom. d'une Monogr., p. 16, 1836. 

— — Besmoulins. Etudes sur les Ech. Foss., p. 400, 1837. 

— — Beshayes, in Lamarck, 2nd ed.. An. sans Vert., t. iii, 

p. 334, 1843. 

— — Sismonda. Mem. geol.-zool. Echin., p. 8, 1843. 

— — d'Orbigny. Paleontol. Fran^., Ter. Cretaces, t. vi, p. 93, 

pi. 814, figs. 6, 7; pi. 815, 1853. 

— CENOMANENSIS, d'Orbigny. lb., p. U 1, pi. 819, figs. 7— 12, 1853. 

— SDBORBICULAEIS, Desor. Synopsis des Echin. Foss., p. 340, 1858. 

— — Cotteau. Echinides de la Sartbe, p. 198, pi. xxxiii, 

figs. 1—6. 1860. 

Diagnosis. — Test oblong, cordiform, rounded and deeply grooved before, contracted 



PROM THE UPPER GREENS AND. 315 

and truncated vertically behind ; superior surface elevated and convex on both sides, with 
a well-marked carina extending from the apical disc to the posterior border ; the inferior 
surface much depressed before, and on each side of the mouth more or less elevated 
along the region of the plastron, and presenting alternate protuberances and depressions 
there, so that the greatest height of this species is about the posterior third of the test. 
Anibulacral summit excentral anteriorly; vent large, situated high up in the anal area. 

Dimensions. — Antero-posterior diameter one inch and a half; transverse diameter 
one inch and three tenths of an inch ; height nine tenths of an inch. I have several 
moulds of this species collected from a siliceous rock in Dorsetshire, which measured 
more than the figured specimen, obtained from the Chloritic Marl near Chard, 
and here drawn as our type because its shell is well preserved with many impor- 
tant details of its structure in siht. I have two large specimens of this Urchin from 
the Cap de la Heve. The largest measures two inches and six tenths in the antero- 
posterior diameter, two and a half inches in the transverse diameter ; and one inch and 
two tenths in height ; the second specimen measures two inches and four tenths in 
length, two inches and three tenths in breadth, and one inch and four tenths in height, 
so that when we reduce these measurements for comparison with those of the figured 
specimen, we find the proportions are nearly the same as relates to length, breadth, and 
height throughout. 

Description. — This is a very neat, oblong, cordiform Urchin ; the round anterior 
border is deeply grooved by the anteal sulcus, the widest part of the body is behind the 
anterior ambulacrum, and from that point backwards the ambitus contracts into the 
posterior border, which is vertically truncated to form the anal area (fig. 1 e). 

The antero-lateral ambulacra curve gently up to the disc, and the postero-lateral pair 
are nearly straight in their course (fig. 1 a). The poriferous zones consist of pairs of pores, 
which are distant from each other below, and approximate above ; in some of the larger 
specimens the pores are oblong below and round above. The anteal sulcus is very deep, 
extending from the mouth to the apical disc ; it is bordered by elevations of the test, 
which form two carinas on the sides of the sulcus (fig. 1 a, d). On these several large 
tubercles are arranged. The single ambulacrum occupies the middle of the sulcus ; its 
avenues consist of very small pores, which are only visible with the aid of a lens. The 
three anterior ambulacra converge around the front of the disc, at a considerable distance 
from the posterior pair, which converge at the hinder part thereof (fig. 1 a). 

The test is very thin, and the inter-ambulacral areas consist of very wide plates (fig. 1 c); 
their surface in both areas is closely covered with a very fine microscopic granulation, in 
the midst of which a number of small tubercles, nearly equal in size, are uniformly spaced 
out upon all the surface of the test. On the sides of the anteal sulcus, and on the cheeks 
and plastron at the base the tubercles are much larger ; they are all raised on bosses with 
crenulated summits, and are perforated and surrounded by a smooth circular zone, 
defined by an outer circle of granules (fig. 1 d, d). 



316 HOLASTER 

The apical disc is narrow and elongated ; its elements consist of four perforated 
genital plates, on the right anterior of which the small raadreporiform tubercle rests 
between the anterior and posterior pair ; two ocular plates are interposed; the single 
ocular is seen at the summit of the single ambulacra, and the two posterior oculars at 
the summits of the hinder pair ; the elements of the disc are closely united together, 
and the surface of the plates covered with fine granules. 

The vent is large, and opens at the upper part of the anal area immediately below 
the carina (fig. 1 e). The periprocte is elliptical, with a well-defined margin accumi- 
nated at both extremities, and having the lower part of the border hollowed out 
(fig. 1 e). 

The mouth is transversely oblong, placed near the anterior border in a depression 
formed by the anteal sulcus. The peristome is transversely oblong (fig. 1 I/), and is 
rounded before, with a thickened projecting lip behind. Around the aperture are several 
pairs of round ambulacral pores arranged in a stellate figure (fig. 1 d). 

Affinities and Differences. — This Urchin was long a puzzle to palaeontologists, and we 
are indebted to d'Orbigny for having removed the confusion that existed, and for 
proving that Defrance's Urchin figured by Brongniart was the true type of the species. 
The English specimens are small, and resemble the Ui'chin described as Holaster Cenoma- 
nensis, d'Orb., which, however, is only a small variety of Hoi. suborbicularis. M. 
Cotteau is disposed to unite this species to Cardiaster fossarius, Bennet, an opinion in 
which I cannot concur, as I feel satisfied that, if my learned friend had before him good 
type specimens of Card, fossarius, he would readily distinguish the differences between 
that Urchin and llol. suborbicularis. Putting aside the question of the lateral fasciole, 
which I have never seen in Card, fossarius, the other features of the test are sufficiently 
distinct to show the differences which exist between them (see PI. LXVIII). 

In Holaster fossarius the shell is shorter and broader than in Hoi. suborbicularis. 
The anteal sulcus is deeper, and retains its depth from the mouth to the disc, whereas 
in Hoi. suborbicularis the sulcus vanishes above the anterior border, and leaves the upper 
surface smooth and undepressed. The carinas on each side of the sulcus are more 
prominent and much sharper in Hoi. fossarius than in Hoi. suborbicularis, and the 
avenues of pores in the antero-lateral ambulacra are wider apart and more petaloid ; 
whilst the base is flatter and the plastron less prominent in Hoi. fossarius than those 
parts are in Hoi. suborbicularis. 

Locality and Stratiyraphical Position. — This Urchin abounds in the bed of Chalk 
with green grains intervening between the Upper Greensand and Chalk-Marl. It is 
found likewise plentifully in the Chalk-Marl itself, and more rarely in the Lower Chalk. 
It has been collected in nearly all the English Counties in which these beds are found, 
but has not been observed in Ireland. 

Tlie Foreign Distribution. — Villers-sur-Mer, Vaches-Noires (Calvados) ; Montague 
St. -Catherine pres Roucii ; Fecamp (Scine-Inferieure) ; Fourneaux, la Madelaine 



FROM THE LOWER CHALK. 317 

(Eure) ; Laubressel, Sainte-Parre pres Troyes (Aube) ; Fourrain, Seigneley, Yonne ; 
Sancerre (Cher) ; Cassis (Bouches-du-Rhone) ; Vit pres Castellane (Basses-Alpes) ; 
Bidart pres Biarritz (Basses-Pyrenees) ; Palarea (Nice) ; Altraaim (Appenzell) ; Qued- 
linbiirg, Prussia ; North Germany, &c. In France it has been collected from the zone 
of Acanthoceras Rhotomagense, Brong., and in strata with Scaphites mqualis in Conde, 
Sarthe, which is precisely the same zone from which our English specimens have been 
collected. 



^^.-^^-^ 



it 




V 



HoLASTER L^vis, w/r.' PLANUS, Muntell. PI. LXXII, fig 2, a—f; PI. LXXIX, 

>- fig- 1 a, h. 

(TV- y ^ 

\/^ 
^ Spatanous planus, Mantell. Geology of Sussex, p. 192, pi. xvii, figs. 9 — 21, 1822. 

HoLASTEB PLANUS, Agassi:. Prodrom. Mem. Soc. de Neuchatel, t. i, p. 183, 1835. 

— — cCOrhigmj, Paleontol. Fran9aise, Ter. Cret., t. vi, pp. 116,821, 

1853. 

— — Besor. Synopsis des Echinides, p. 342, 1858. 

Diapiosis. — Test cordate, widest across the middle third, gradually diminishing in 
width to the posterior border, which is narrow and slightly truncated, anterior border 
a little depressed by the anteal sulcus. Anibulacral summit subcentral, upper surface 
convex, gently declining all round towards the ambitus ; periprocte in the upper part of 
the anal area. Under surface flat, plastron prominent, mouth-opening near the border 
in a small depression, peristome transversely oval and bilabiate. Surface of the test 
smooth. 

Dimensions. — Antero-posterior diameter two inches ; transverse diameter one inch 
and eight tenths ; periprocte above the base line seven tenths of an inch. 

Descrijjiio?i. — This Urchin has a cordate outline, and is widest anteriorly, its greatest 
transverse diameter being immediately behind the antero -lateral ambulacra ; from this 
point it tapers gently to the posterior border, which presents a narrow truncation. 
The upper surface is convex, and the vertical summit with the apical disc is subcentral ; 
to this point all the ambulacral areas converge (PI. XXll, fig. 2 d). The antero-lateral 
pair are short, slightly bent, apetaloid, and lanceolate, they pass obliquely up the sides of 
the test. The poriferous zones are narrow and superficial, the pores small and placed in 
pairs ; there are forty pairs of holes in each of the avenues above the ambitus, which 
are entirely invisible below ; the postero-lateral pair are equally oblique and lanceolate, 
and their avenues of pores the same. In the figured specimen there are thirty pairs in 
each avenue. The single ambulacrum is lodged in a wide, shallow anteal sulcus which 
only slightly depresses the anterior border and entirely disappears in the upper half of 
its length (fig. 2 a, h, d). 

41 



318 HOLASTER 

The apical disc is small, long, and narrow ; and its elements are so closely welded 
together that I have failed to detect the sutures which divide them (fig. 2 b). 

The under surface is moderately flat about the cheeks and side border; it is ele- 
vated in the middle by the prominence of the plastron, and the path of the postero-lateral 
areas along the base is shown by a wide, smooth surface on each side of the central 
elevation (fig. 2 a). 

The month-opening is small, situated a short distance from the border in a depression 
formed by the incurving of the anteal sulcus. The peristome is transversely oval, and 
placed about the junction of the first with the second fourth of the total basal length of 
the test (fig. 2 a). 

The posterior border is very narrow, the anal area small, and the vent opens in its 
upper part ; the oval periprocte is situated high up in this space, near the point where 
the convex part of the back bends over towards the truncated portion of the posterior 
border (fig. 2 e). 

The surface of the plates is covered with a microscopic, close-set, miliary granulation, 
beautifully preserved and shown in some of the specimens derived from the Grey 
Chalk. On the larger plates a few small tubercles are arranged without much order, 
from six to eight of these may be counted upon each of the plates (fig. 2 b). 

Ajjinities and Differences. — This species resembles some of the large forms of HoL 
l(Evis, from which it differs very little ; the ambulacral summit is slightly subcentral, which 
makes the direction of the ambulacral areas nearly uniformly quinque-radiate on the 
upper surface, as seen in fig. 2 b. The anteal sulcus is shallow, the posterior border 
narrow, and the position of the periprocte in the anal area is much the same in Hoi. 
planus as in Hoi. laevis. The rotundity and smoothness of the test, and the width and 
shallowness of the anteal sulcus in Holasier planus form marked differences between it 
and Hoi. suborbicularis, with which it has sometimes been confounded, and the same 
characters serve to establish the differences between Hoi. 'planus and Hoi. subrjlobosus. 

Locality and Stratigraphical Position. — This species is said to characterise a well- 
marked zone of the Lower Chalk at Lewes and Dover, and I have specimens collected 
from the Medial Chalk at Swaffham, Norfolk, sent by my old friend the late ]Mr. C. 
B. Rose. It occurs also in the chalk with flints (in lower portion of the Upper Chalk) 
near Lewes. The specimen (PI. LXXIX, fig. 1) from the Collection of the Rev. Thos. 
Wiltshire, F.G.S., shows that the species was gregarious. 

Many geologists express surprise that several species of Echinides are recorded by me 
as having been found in the Grey Chalk, Lower Chalk, Chloritic Chalk, and Upper 
Greensand. There can be no doubt about the fact of the presence of this species 
therein ; other forms also have often occurred to me when noting the distribution of 
species in these beds. It may be suggested whether some artificial divisions, in the natural 
groupings of the strata, have not beeu made on petrological rather than on palseon- 
tological grounds. If this conjecture should turn out to be correct then the Lower 



FROM THE LOWER CHALK. 319 

Chalk and Upper Greensand may be bracketed together, and not separated by a hard- 
and-fast hne as at present. 



HoLASTER suBGLOBosus, Leske, sp. PI. LXXIII, figs, a — //. 

Spatangus SUBGLOBOSUS, Leslce. Add. ad Kleinii Disp. Echin., p. 240, pi. liv, 

figs. 2, 3, 1778. 
Echinus subglobosus, Linnc. Gmelin's Systema Natura, p. 3198, 1789. 

— — Lamarck. Encyl. Method., Zoophytes., pi. 157, figs. 7, 8, 

1791. 
Spataitgus subglobosus, LamarcA-. Animaux sans Vertebres, t. iii, p. 33, 1816. 

— — Beslongchamps. Encycl. Method., Zoophytes, p. 689, 

1824. 

— — Goldfuss. Petref. Germanise p. 148, pi. xvii, fig. 4, 

1826. 

— — Blainville. Zoophytes, Diet. Sc. Nat., t. Ix, p. 185, 1830. 

— HEMisPH^EEicus, PAz'ffips. Geol. of Yorkshire, p. 91, pi. i, fig. 16, 1835. 
HoLASTEK SUBGLOBOSUS, Agassiz. Prodrome, Mem. Soc. Kat. de Neuchatel, t. i, 

p. 183, 1836. 
Spatangds SUBGLOBOSUS, Desmoulitts. Etudes sur les Echinides, p. 398, 1837. 
HoLASTEE SUBGLOBOSUS, Affossic. Descr. des Echin. foss. de la Suisse i, p. 13, 

pi. ii, figs. 7—9, 1 839. 

— ALTUS, Agassiz. Ibid., pi. iii, figs. 9 — 10, 1839. 

— SUBGLOBOSUS, Romer. Petref. der norddeutschen Kreidegebirges, p. 34, 

1840. 
HoLASTER SUBKOTUNDUS, Sismonda. Echin. Foss. del Cont. di Nizza, p. 5, 1843. 

— SUBGLOBOSUS, Morris. Catal. of British Fossils, p. 54, 1843. 

— — Agassis ^ Besor. Catal. raisonne des Echinides, p. 133, 

1847. 

— — A. Gi-as. Oursins Fossiles de I'lsere, p. 6.3, 1848. 

— — Sorignet. Oursins de I'Eure, p. 6", 1850. 

— — ■ i^or6e«, in Dtson's Geol. of Susses, p. 341, pi. xxiv, fig. 2, 

pi. xxix, fig. 1, 1850. 

— — Bronn. Lethsea Geognost., p. 204, pi. xxxi, fig. 2 a, a, 

1852. 

— • — Forbes. Mem. Geol. Surv. Decade iv, pi. vii, 1852. 

— — Quenstedl. Handbuch der Petref., p. 591, pi. 1, fig. 14, 

1852. 

— — (TOrhigny. Paluont. FraD9., Terr. Cret., t. vi, p. 97, pi. 

816, 1853. 

— — Leymerie et Cotteau. Catal. des Echin. Foss. des Pyre- 

nees ; Bull. Soc. Geol. de France, 2me serie, t. xiii, 
p. 350. 1856. 
— - — Stromheck. Glieder. des Planers, in N.-W. Deutschland ; 

Zeitschr. der Deutschen geol. GeseUsch., vol. ix, p. 415, 
1857. 



320 



HOLASTER 



HOLASTER SUBGLOBOSUS, 



Cotteau e.t Triger. fich. foss. de la Sarlhe, p. 202, pi. 

xxxiii, figs. 7, 8, 1860. 
Lory. Descr. dii Dauphine, pp. 3.50, 367, 1860. 
Bvjardin et Htipe. Suites a Buffon, Echinodermes, 

p. 592, 1862. 
Strombeck. Die Kreide bei Luneburg ; Zeitsch. deutsch. 

Gessell., 1863. 
Cotteau. Catal. des Echin. de I'Aube, p. 39, 1865. 
Ooster. Synopsis des Echin. Foss. des Alpes Suisses, 

p. 96, 1865. 
Heer. Die Urwelt der Schweiz, p. 205, 1865. 
Cotteau. Echin. Foss. de I'Yonne, t. ii, p. 244, pis. Ixviii, 

kix, 1866. 
Renevier. Notice sur les Alpes vaud., p. 171, 1867. 
Bucaille. Foss. C^noraaniens de Rouen, p. 6, 1867. 
Jaccard. Descr. Geol. du Jura vaud. et Neuchat., p. 120 

1869. 
Greppin. Descr. Geol. du Jura Vernois, p. 143, 1870. 
De Loriol. Echinologie Ilelvetique, p. 330, pi. xxvi, 

figs. 11—14, 1873. 



Diagnosis, — Test of a subglobular form, very nearly as broad and as high as it is 
long. The upper surface regularly convex, sometimes a little elevated at the summit ; a 
well-marked carina rises on the middle of the single inter-ambulacrum ; the under 
surface more or less convex ; the ambitus rounded and inflated ; the ambulacral summit 
slightly excentral in the anterior direction ; posterior border narrow, obliquely truncated 
downwards and inwards ; vent in the upper part of the area. 

Dimensions. — From a number of specimens collected by the Geological Survey from 
diflPerent localities, the following table of comparative dimensions of six specimens, 
selected on account of their diflerences, was prepared by my colleague the late Professor 
Edward Forbes, to illustrate the variation in the proportions of this species. 



No. 

1 


Locality. 


stratum. 


Length. 


Breadth. 


Height. 


Dover 


Chalk-Marl 


2i\ 


2t% 


Ht 


2 


Do. 


Lower Chalk 


O 


2 


•tV 


3 


Chaldon 


Chloritic Marl 


1 ' 1 


Hi 


1t\ 


4 


Do. 


Do. 


IH 


2 


ItV 


5 


Do. 


Do. 


lA 


^-h 


ItV 





Do. 


Do. 


ItV 


lA 


1t\ 



Varieties. — There is a curious variety of this species, in which the anteal sulcus is 



FROM THE LOWER CHALK. 321 

■deeply impressed into an almost acute fiuTrow. Professor E'orbes found this abnormal 
form at the junction of the Chalk-Marl and Upper Greensand, near Abinger, in Surrey; 
and there is a very fine and large specimen of it in the British Museum Collection. 

I have a large specimen of this Urchin in my cabinet, collected from the Planer at 
Rheten, which measures in length 2jj%th inches, in breadth 2^oth inches, and in 
height 2 inches. 

Bescnption. — This vi^ell-knovifn Urchin of the Lower Chalk has long been familiar to 
collectors of Cretaceous fossils. It was very fairly figured by Leske in his 'Addita- 
menta ad Klein.,' and has kept its place well in the list of synonyms ever since. 
Lamarck, however, appears to have mistaken this fossil, as he refers to Leske's figure a 
specimen from Grignon pros Versailles, where the formation is Tertiary ; so either an error 
in the species, or a mistake in naming the locality, has been committed. 

The test is large, subcircular, or cordiform, almost as wide as it is long (fig. 1 a) ; the 
body is dilated and slightly grooved anteriorly, subacuminated and obliquely truncated 
posteriorly (fig. 1 b, c). The upper surface is convex and the ambitus uniformly inflated 
(fig. e, d) ; the base is likewise convex, except near the anteal depression for the mouth 
(fig. 1 b). The ambulacral summit is nearly central (fig. 1 a). 

The antero-lateral ambulacra are lanceolate, apetaloid, and curve gently backwards 
and inwards, forming a flat Gothic arch over the anterior surface of the test (fig. 1, a). 

The postero-lateral pair are lanceolate, apetaloid, and straight (fig. 1, d). The 
poriferous zones in the two pairs of areas are very much alike. The pores of each pair 
are set well apart, and connected by a furrow, but below the middle and in the wider 
plates they become smaller and closer. There are about forty pairs of holes in each 
avenue of the anterior pair, and a lesser number in the avenues of the posterior pair 
(fig. l,y, h). 

The single ambulacrum has a special structure. It is lodged in the anteal sulcus, 
which is wide and shallow. Its surface is concave and smooth, and it is linear-lanceolate. 
The apices of the three anterior ambulacra converge at some distance from those of the 
posterior pair (fig. 1, a), which meet near each other at the posterior portion of the apical 
disc. The poriferous avenues of the single ambulacrum are very narrow, the pores quite 
microscopic, and fewer in number than in the pairs (fig. 1, //). 

The inter-ambulacral areas (fig. 1 a, c) are formed of large wide plates, which have 
their surface covered with a close-set microscopic granulation ; and arising in their midst 
are a series of three or four irregular horizontal rows of primary tubercles. I have given 
a most accurate drawing of this structure in fig. 1 (/, which shows two inter-ambulacral 
plates and a portion of an ambulacral area magnified three times ; in fig. \ h a portion 
of the single ambulacrum magnified three times is shown ; and in fig. 1 i is given a view 
of three primary crenulated and perforated tubercles magnified, with the circles of 
granules surrounding the areolae and filling in the intervening space with moderately 
sized granules. 



322 HOLASTER 

The apical disc is much elongated (fig. 1 a, f) ; it is composed of four perforated 
genital plates ; the right anterior plate has its surface covered with the madreporiform 
body, and is separated from the posterior pair by two of the perforated ocular plates, 
which are interposed between the anterior pair, and produce the length and narrowness of 
the disc ; all the elements of the disc are closely soldered together, and densely covered 
witli microscopic granulations, a few solitary tubercles only are seen in their midst. 

Where the anteal sulcus curves round the ambitus (fig. 1 e) a depression is formed 
at the base (fig. 1 b), in which the mouth is situated ; the peristome is a small, trans- 
versely oval, bilabiate aperture ; the upper lip is thickened and higher than the lower, 
and the buccal extremities of the poriferous avenues form an irregular stellate figure 
around the peristome (fig. 1 b). 

The posterior border of the test is truncated obliquely downwards and inwards 
(fig. 1 c), and in some specimens slightly hollowed into a concave channel below 
the vent, which occupies the upper part of the anal area (fig. 1 d), in a position about 
half the height of the test. The periprocte is vertically of aa elliptical figure (fig. 1 d), 
and its upper angle forms the termination of the dorsal carina which extends backwards 
from the disc to the border. 

Affinities and Differences. — This Urchin is so well characterised by its specific 
features that it is not easily mistaken for any other. Hoi. cor-avium, Laralc, has been 
ascertained by d'Orbigny's inspection of the type in the museum to be a siliceous mould 
of Hoi. subfflobosus ; and Hoi. nasutus, labelled by M. Agassiz in the museum, is only a 
specimen of Hoi. subt/lobosus deformed by pressure. 

Locality and Straii(jrapldcal Position. — This Urchin abounds in the bed of Chalk 
with green grains intervening between the Upper Greensand and Chalk-Marl. It is 
found also plentifully in the Chalk-Marl itself and more rarely in the Lower Chalk. I 
have had many fine specimens from the Chloritic Marl near Chard, and from the Chalk- 
Marl near Lewes, in Sussex. The Chalk-Marl of Wiltshire and of Dorsetshire has yielded 
many specimens. This species, says Forbes, has not been found in L'eland. 

Foreign Localities, — It is found at the Mountain Sainte-Catherine, near Rouen, 
Fecamp, and Havre, at Saint-Parre and Laubresel, near Troyes, Aube ; with 
Acantlioceras Tiotomagense, Brong., at Pourraiu, and Seigneley, Yonne ; Sancerre, Cher ; 
Cassis, Bouches-du-Rhone ; Bidart, near Biarritz, Basses-Pyrenees ; Villers-sur-Mer, 
Calvados ; Trinite, near Nice. In Switzerland, in the ' Etage Cenomanien,' Monsieur 
De Loriol records it from Sainte-Croix, Vaud. ; Cheville, Valais ; Ried, near Bienne, 
Berne ; Summit of Sentis, Ebenalp, Sentis ; Seealp, Appenzell, Yberg-Sil, Schwytz ; 
Lac Saint-Point, Jura. In Germany, Goldfuss records it from Quedliuburg, Prussia ; 
Neuwallmoden and Langelsheim, Brunswick. 



FROM THE LOWER CHALK. 323 



HoLASTER Trecensis, Lei/merio. PI. LXXIV, fig. 2, a — e. 

HoLASTER TRECENSIS, Leymerie. Mem. do la Soc. geol., p. 2, pi. ii, fig. 1, 1842. 

— — Agassiz. Catal. raisonne, p. 134, 1847. 

— vUjLVijkv?iV. Ukxiuk, Agassiz s.uA Desor. Ibid., p. 13"), 1817. 

— TRECENSIS, (POrbigny. Prodrome 2, p. 2(i!), No. 1 Kil, 1847. 

— — — Pal. Fran9., Ter. Cretaces, vol. vi, p. 101, 

pi. 847, 1853. 

Diagnosis. — Test oblong, cordiform ; upper surface very mucli elevated, rounded, and 
grooved before, tapering gently to a narrow truncation behind. Ambulacral summit 
nearly central ; under surface very flat ; mouth near the border. Vent in a small 
marginal anal area near the angle ; upper surface covered with large tubercles, arranged 
without much regularity upon both areas. 

Dimensions. — Antero-posterior diameter two inches and four tenths ; transverse 
diameter two inches and four tenths j height one inch and five tenths. 

Description. — The test is oval and cordiform, much inflated, and nearly as broad as 
long ; enlarged and sinuous before, accuminated behind. The upper surface is much 
elevated and very convex, the outlines antero-posteriorly, as well as laterally, describing 
regular curves (fig. 2 c, d). The ambidacral summit is nearly central (fig. 3 a), where 
we find the apical disc, which is small, and shows four perforated genital plates. The 
central portions of the inter-ambulacra are rather prominent, which imparts an angular 
appearance to the ambitus (fig. 2 d). The base is very flat, with the exception of a 
slight prominence in the middle of the plastron, where we observe seven alternate 
elevations, with a connective zigzag ridge between (fig. 2 (j). The anterior portion near 
the anteal sulcus is slightly depressed (fig. 2 b), where we find the mouth-opening, which 
is large, and transversely oval. The peristome is bilabiate ; the anterior lip is depressed 
and convex, and the posterior elevated and prominent. The vent occupies the posterior 
border, and opens near the base ; it is situated in a small triangular anal area, slightly 
excavated out of the border (fig. 2 e). The periprocte is longitudinally oval, placed under 
an angular projection in the median line, with two lateral ridges to divide the area from 
the ambital circumference (fig. 2 c). 

The ambulacral areas are very feebly defined in this Urchin ; the anterior single area 
is lodged in the sulcus; its poriferous zones are only slightly visible near the summit. 
The antero-lateral and postero-lateral pairs are narrowly lanceolate. The anterior pair 
curve slightly forwards, and the posterior pair are straight (fig. 2 a). The poriferous zones 
are formed of transverse oblong pores arranged in pairs, and the anterior is smaller than 
the posterior row ; they extend half-way over the upper surface and sides, and disappear 
above the ambitus (fig. 2 c, d). 

The tubercles are of two kinds ; small tubercles, which are seen in the ambulacral 



324 HOLASTER 

areas and on other parts of the test, and large tubercles, developed upon the inter- 
ambulacral plates without much order or regularity, and varying much in number in 
difTerent specimens. These tubercles are perforated at the summit, and raised upon 
bosses with crenulated rims. The specimen I have figured shows this tubercular 
structure to perfection, but the majority of specimens want the profusion of large 
tubercles seen on the figured shell (PI. LXXIV, fig. 2). Besides the tubercles just 
described, the surface of the plates is covered with microscopic granules which form 
circles around the base of the tubercles and crowd the spaces between them with a close- 
set granulation. It is only in well-preserved specimens, however, that this structure 
can be observed, and then only by the assistance of a lens. 

Jffinities and Differences. — This fine Urchin was well figured by the late Prof. 
Leymerie in 1842,^ and afterwards by d'Orbigny in 1853." I had been fortunate in 
procuring a very fine example of this Holaster from the Grey Chalk of Folkestone, and I 
desired my late friend Mr. Bone to make most accurate figures of it, which he has done, 
and given five beautiful drawings of the same in Plate LXXIV, fig. 2 a — e. 

At first sight one naturally concludes that Hoi. Trecensis, Ley., is a well-defined form, 
and fully entitled to specific rank, but a closer examination of the test, and a comparison 
of it with other fossils considered to be Hoi. carinatus, weaken our faith in this belief. 
Characters at first sight thought to be specific appear to be evanescent. The size and 
number of the tubercles on the upper surface of Hoi. Trecensis, for instance, are not 
constant, seeing that in some specimens they dwindle away, and in others almost dis- 
appear. Finally, the close identity of Hoi. Trecensis with Hoi. carinatus, from being a 
doubt, becomes a certainty. Now arises the next question, in what does Hoi. carinatus 
differ from Hoi. Icevis ? Failing to discover the specific difi'erences which many eminent 
palaeontologists have thought they saw in these different forms, we have at length arrived 
at the conclusion that my learaed friend Mons. De Loriol came to, after a patient and 
exhaustive study of Hoi. Icevis, namely, that these three forms — Hoi. carinatus, Hoi. 
Trecensis, and Hoi. Icevis — are only varieties more or less defined of Hoi. Icevis, De Luc. 

Locality and Stratigraphical Position. — The fine specimen figured in PI. LXXIV, 
fig. 2, was collected from the Grey Chalk, near Folkestone, and I have several other 
large specimens from the Lower Chalk of Wiltshire and from the Medial Chalk, 
Swaffham, Norfolk. 

Foreign localities. — Prof. Leymerie found his type specimen at Saint-Parre, near 
Troyes, Aube ; it has been collected likewise at Mont Saint-Catherine, Rouen, Seine- 
Inferieure, with Acanlhoceras Bhotomagense ; and from the Chloritic Chalk in the 
environs of Saint-Croix, Vaud, Switzerland. 

^ 'Mem. de la Soc. geol. de France,' p. 5, pi. ii, fig. 1, 18i2. 

2 ' Paleontologie Frnncaise, Ter. Cretaces,' torn, vi, pi. 847, 1853. 



THE 



paltEontographical society. 



INSTITUTED MDCCCXLVII. 



VOLUME FOE 1882. 



LONDON: 

MDCCCLXXXII. 



MONOGRAPH 



ON THE 



BRITISH FOSSIL 



ECHINODERMATA 



FROM 



THE CRETACEOUS FORMATIONS. 



BY 

THOMAS WRIGHT, M.D., F.R.S., F.G.S., 

VrCE-PRESIDENT OF THE PAL^ONTOGRAPHICAL SOCIETY; CORKESPONDING MEMBER OF THE ROYAL SOCIETY OP SCIENCES 

OF LliiGE; THE SOCIETY OF NATURAL SCIENCES OF NEUCHATEL; VICE-PRESIDENT OF THE COTTESWOLD 

naturalists' FIELD CLUB; CONSULTING SURGEON TO THE CHELTENHAM HOSPITAL; 

AND MEDICAL OFFICER OF HEALTH TO THE URBAN SANITARY DISTRICTS 

OF CHELTENHAM, CHARLTON KINGS, AND LECKHAMPTON. 



VOLUME FIRST. 
PART TENTH. 

CONCLUSION. 

Pages i— xviii, 325—371 ; Plates LXXVI— LXXX. 
With Title-page and Dikections for Binding. 



LONDON: 
PRINTED FOR THE PALiEONTOGRAPHICAL SOCIETY. 

1882. 




PBINTED BY 
J. E. ADLARD, BAKTHOLOMEW CLOSE. 



FROM THE UPPER CHALK. 



325 



Cardiaster pillula, Lamarck. PI. LXXI, fia;s. 1 — 3. 



Ananchytes pillula, 

Spatangus pkunella, 

Ananchytes pillula, 

nucleolites coravium, 
Spatangus pillula, 

Ananchytes analis, 

Holaster pillula, 

Ananchytes (Holaster) 
Caediastee pilula, 



Lmnarck. Animaux Sans Verteb., torn, iii, p. 27, 

No. 11, 1816. 
Mantell. Geology of Sussex, pi. xvii, figs. 22, 23, 

p. 193, 1822. 
Bedongchamps. Encycloped. Method., torn, ii, p. 64, 

1824. 
Cutullo. Saggio de Zool., p. 226, pi. 2, fig. e, 1827. 
Desmoulins. Etudes sur les Echinides, p. 406, 

No. 50, 1837. 
jRoemer. Norddeutsch Kreide, pi. 6, fig. 18, p. S.i, 

1840. 
Agassi: and Desor. Catal. raisonne. An. Sc. Nat., 
torn, viii, p. 29, 1847. 
pilula, Forbes. Mem. Geol. Surv., decade iv, pi. viii, 1852. 
d'Orbigny. Palcontol. Franijaise Terr. Cretaces, 
torn, vi, p. 126, pi. 824, 1853. 



Diagnosis. — Test oblong, lofty, alvva3's more or less elevated ; sides tumid ; anterior 
border round and flattened ; posterior accuminated and truncated ; base flatly convex 
with sharp angulated sides, mouth near the anterior border ; vent elevated in the middle 
of the posterior border ; upper surface highly arched, with a carina passing from the disc 
to the vent ; apical disc narrow, elongated, and nearly central. 

Dimensions. — Height, ^ of an inch ; antero-posterior diameter, y^ of an inch ; 
transverse diameter, yo ^^ ^" inch. 

The proportional dimensions of this Urchin vary considerably, a fact which may 
best be illustrated by the measurement of six specimens of different bulk, in inches and 
parts of an inch, as shown in the following table : 



TEST. 



Height 

Antero-posterior diameter. 

Lateral diameter 

Vent aboTe margin 



No. 1. 


No. 2. 


No. 3. 


No. 4. 


No. 5. 


No. 6. 


OftJ 


Of 


Oi 


Oi 


Ot*. 


OH 


1 


Ot-V 


Ot'« 


OA 


Oi! 


Oii 


Ot% 


OtV 


OtV 


0/. 


Ot% 


OtV 


OA 


Ot% 


Ot\ 


OtV 


Ot\ 


OtV 



Description. — Test oblong, always more or less elevated, tumid above, inflated at 
the sides and flattened at the base ; the anterior border depressed, with the central 
sulcus feebly developed and the posterior border accuminated and abruptly truncated. 

42 



326 CARDIASTER. 

The anteal and antero-lateral ambulacra are short, lanceolate and nearly vertical ; 
the postero-lateral long, ascending obliquely forward, and conjointly forming an arch 
which encloses the posterior truncated border with the circular vent about half way up the 
total height of the test (see Table). The plates of the ambulacra are large and broad, 
each equal to as much or rather more than half the height of an interambulacral plate. 
In a rather large example of this species there are seventeen dorsal plates in each vertical 
row of the anteal ambulacrum, about fourteen and thirteen respectively in the rows of each 
lateral ambulacrum, and seven in each vertical row of each lateral inter-ambulacrum 
(PI. LXXI, fig. 1 c). These plates all bear minute scattered primary tubercles, with 
myriads of interspersed granules (PI. LXXI, fig. 1 li). 

The upper surface is convex, and more or less arched throughout ; the highest point is 
in the anterior third, from whence it gently declines towards the posterior border (figs. 1 c 
and 3 a). The apical disc is closely wedged in between the other plates of the test, and 
often distinguished with difficulty; it is situated about the centre of the test, rather 
nearer the anterior border, and is narrow and extremely elongated (fig. 1 e) ; the ovarial 
plates being placed in line behind each other, and four are perforated. The ocular 
plates are very small, and can only be discerned by the aid of a magnifying lens. The 
madreporiform body is very small and indistinct. In some flint casts the four ovarial 
holes are seen, and the pairs of pores in the poriferous zones very well shown (fig. 2) ; 
their courses are much better traced out in such moulds than in specimens with the test 
preserved. 

From the posterior side of the apical disc to the upper margin of the vent a carina 
more or less acute is developed (fig. 1 a), this ends in a beak -shaped process which 
overhangs the anal aperture. 

The under surface is slightly convex, and a little angular along the median line, 
without any concavity around the mouth, which occupies a position near the anterior 
extremity, about one fourth of the length of the test from the margin, which in the 
region of the anteal ambulacrum is slightly sinuous (fig. 1 b). The oral aperture is 
roundish or ovate, the fore lip is depressed, and the hinder lip turned and elevated, but 
not overlapping. 

The vent of an oval form occupies an elevated position in the posterior border (figs. 
1 (^and 3 a). This aperture was defended by a series of small plates, eight polygonal 
calcareous pieces forming the outer, and ten smaller pieces the inner circle of the lid, so 
that the periprocte was entirely closed with the exception of a small central aperture for 
the passage of the rectum. I have given an accurate drawing of these anal ossicles iti 
situ for shutting up the periprocte in fig. 3 b. 

This beautiful little Urchin likewise possesses a band of minute granules towards the side 
margins of the ambitus, forming thei'e a fasciole like a Cardiaster ; for this reason 
it is now removed from the genus Ananchytes, where it was placed, but in which no 
fascioles exist, into the group which possesses this granular band along the margin of the 



FROM THE UPPER CHALK. 327 

cheeks. In other respects its form and structure has many affinities with Ecldnocorys on 
the one side and Holaster on the other, between which it forms a connecting link. 

Locality and Stratiyraphical Position. — It is found in the upper chalk of Kent, 
Sussex, and other Enghsh counties. 

In France it is collected from the upper chalk at Meudon, near Paris ; Dens, Poigny, 
Yonne ; Beauvais, Oise ; Saintes, Charente-Inf^rieure. 

In North Germany it has been found at Peine, at Yseburg, near Hanover. 

History. — This Urchin was first described by Lamarck as Ananchytes 2nllula, and after- 
wards by Deslongchamps under the same name. Desmoulins removed it into the genus 
Spatanyus,'RoQmeT described and figured it ?iS Ananchytes analis;Agassiz andDesor removed 
it into the genus Holaster. Forbes called it Ananchytes {Holaster) jnlhila, and described 
and figured it in his Memoirs of the Geological Survey in much detail and with great 
accuracy ; and finally D'Orbigny, having ascertained the presence of the fasciole which 
extends along the margin and under the posterior border, removed it into the genus 
Cardiaster, among its marginal fasciolated congeners. 



Ge7ius — EcHiNOCORTS, Breyiiius, 1732. 
Ananchytes, XamarcA, 1801. 

Form of the test more or less oval ; upper surface much elevated, helmet-shaped, 
convex, conoidal, or rounded ; under surface flat. 

Ambulacral summit central, the poriferous zones occupy the middle of the ambulacral 
plates ; the single ambulacrum similar in structure to the antero- and postero-lateral 
pairs. The pores round or elongated, alike identical in structure, disposed in single 
pairs, set obliquely widely apart in the middle of the ambulacral plates, and forming two 
rows in each area, which radiate from the summit and diverge towards the circumference. 

Apical disc elongated, formed of four ovarial and five ocular plates. The two pairs 
of ovarial plates are separated by a pair of oculars. 

Under surface very flat. Mouth-opening near the anterior border transversely oval ; 
peristome bilabiate, situated in a depression, and surrounded by a stellate arrangement of 
primary tubercles, which diverge from the circumference of the peristome. 

Vent marginal or infra-marginal ; periprocte small and oval in a vertical direction. 

Surface of the plates covered with small primary tubercles ; those at the base are 
larger and more developed, some are raised upon bosses with crenulations, and all are 
perforated at the summit. 

The Echinocorys resemble the Ilolasters, but are distinguished from them in having 
the single ambulacrum precisely similar to the others, and by the absence of the anteal 
sulcus. The position of the periprocte is likewise entirely marginal or infra-marginal. 



328 



ECHINOCORYS. 



This genus was well established by Breynius, in 1732, and illustrated with good 
figures; it is to be regretted that Lamarck, in ISOl, suppressed the name EcUnocorys, 
and proposed, without any reason for it, that of Ananchytes, now so well known to all 
geologists ; still, in justice to Breynius, I am under the necessity of restoring his name in 
order to carry out the principle which has guided me in the nomenclature I have adopted 
throughout this work. 



EcHiNOCORYS VULGARIS, Breynius. PI. LXXVII, figs. 1 — 11. 



Cap-stones, oval form, Plot. Nat. Hist, of Oxfordshire, p. 92, tab. ii, 1677. 

EcHixocoKYs VULGARIS, Breynius. Schediasma de Echinis., p. 58, pi. iii, fig, 2, 

1732. 
Leske. Apud Klein Dispos. Echinod., p. 175, pis. xv, 

A, B, 1778. 
Leske. Ibid., p. 178, pi. xliii, fig. 1, 1778. 
Leske. Ibid., p. 183, pi. xvi, c, D; pi. xvii, fig. a, h, 

1778. 
Leske. Ibid, p. ISO, pi. xvi, figs, a, b, 1778. 
Gtnelin. Systema Naturae, t. i, p. 3184, 1789. 
Gmelin. Ibid., p. 3185. 
Gmelin. Ibid. 
Encycl. Method. Mollusques et Zoophytes, t. i, p. 143, 

Atlas, t. ii, pi. 154, figs. 12—17, 1791. 
Lamarck. An. sans Vert., t. i, p. 348, 1801. 
Parkinson. Organic Remains, vol. iii, p. 21, pi. ii, fig. 4, 

1812. 
Lamarck. Animaux sans Vertebres, vol. iii, p. 25, No. 1, 

1816. 
Lamarck. Ibid., No. 2. 
Lamarck. Ibid., No. 3. 
Lamarck. Ibid., No. 4. 
Lamarck. Ibid., No. 10. 

Defrance. Die. Sc. Nat., vol. ii, Suppl., p. 40, 1816. 
Defrance. Ibid., p. 4 1 . 
EcHiNiTEs scuTATL'S, major et minor, ScMotheim. Petrefaktenkunde, p. 309, 1820. 
Ananchytes ovata, Brongniart (Cuvier). Geol. Environs de Paris, p. 390, 

pi. M, fig. 7, A, B,D, 1822. 

— HEMisPH:.ffRiCA, Broriffniart. Ibid., fig. 8, a, B, c, 1822. 
EcHiNOCORYS SCUTATUS, Mantell. Geology of Sussex, p. 191, 1822. 
.\nanchytes ovata, Beslongchamps. Mollusques et Zoophytes, t. ii, p. 61, 

1824. 

— striata, I) eslong champs. Ibid., p. 62, No. 2. 

— GiBBA, Deslongchamps. Ibid., p. 62, No. 3. 



— SCUTATUS, 

OVATUS, 

MINOR, 

— pustulosus, 
Echinus scctatus, 
echinocorytes ovatus, 

pustulosus, 

Ananchites pustulosa, 

OVATUS, 

echinocorys scutatus, 
Ananchytes ovata, 

— striata, 

— gibba, 

— pustulosa, 

— semiglobus, 

AnANCHITRES OVATUS, 

Ananchites carinatus. 



FROM THE UPPER CHALK. 



329 



Ananchytes pxistulosa, 

- semiglobus, 

- OVATUS, 

- conoiueus, 

- striatus, 
echino-corys ovatus, 
Ananchytes ovatus, 

striatus, 

- pustuloses, 

semiglobus, 

GIBBUS, 

— ■ GIBBA, 

- HEMISPH^RICA, 

GIBBA, 

PUSTULOSA, 

STRIATA, 

GIBBA, 

- SEMIGLOBUS, 

HESIISPH^RICA, 

CONOIDEA, 

- PUSTULOSA, 

- OVATA, 

- CONOIDEA, 

- STRIATA, 

GIBBA, 

PUSTULOSA, 

HEMISPH^RICA, 

- SEMIGLOBUS, 

- OVATA, 

STRIATA, 

CRASSISSIMA, 

CONICA, 

OVATA, 

STRIATA, 

GIBBA, 

PUSTULOSA, 

■ — SEMIGLOBUS, 

CONOIDEA, 

HEMISPII^RICA, 

OVATA, 



Dedongdiamps. Ibid., No. 4. 

Beslongchawps. Ibid., p. 63, No. 5. 

Goldfuss. Petrefact. Germanise, vol. i, p. 145, pi. xliv, 

fig. 1, 1826. 
Goldfuss. Petrefact. Germanise, vol. i, p. 145, pi. xliv, 

fig. 2, 1826. 
Goldfuss. Ibid., fig. 3. 

Mantell. Geol. Transact., vol. iii, p. 205, 1829. 
BlainvUle. Zoophytes, Diet. So. Nat., t. be, p. 187, 1830. 
Blainville. Ibid. 
Blai?iville. Ibid. 
Blainville. Ibid. 
Blainville. Ibid. 
Agassiz. Monogr. Eadiaires ; Mem. Soc. des Sc. Nat. 

de Neuchate], vol. i, p. 183, 1835. 
Agassiz. Ibid. 
Agassiz. Ibid. 
Agassiz. Ibid. 
Grateloup. Act. Soc. Lin. Bord., t. viii., Mem. Oursins 

Fos8.,p. 60, 1836. 
Grateloup. Ibid., p. 61. 
Grateloup. Ibid., p, 62. 
Grateloup. Ibid,, p. 62. 
Grateloup. Ibid., p. 62. 
Grateloup. Ibid., p. G3. 

BesMoulins. Etudes surles Echin.,p. 369, No. 1, 183". 
Bes Moiditts. Ibid., p. 370, No. 2. 
Bes Moulins. Ibid., No. 3. 
Bes Moulins. Ibid., p. 372, No. 4. 
Bes Moulins. Ibid., No. 5. 
Bes Moulins. Ibid., p. 374, No. 6. 
BesMoulins. Ibid., No. 8. 

Agassiz. Echin. dela Suisse,p.30,pl.iv,fig3.4 — 6, 1839. 
Agassiz. Catal. Syst. Ectyp. Echin. Foss. Mus. Neoc, 

p. 2, 1840. 
Agassiz. Ibid. 
Agassiz. Ibid. 
Dvjardin. In Lamarck, Anim. sans. Vert., 2 ed., t. iii, 

p. 316,1840. 
Biijardin. Ibid., No. 2. 
Ibid,, No. 3. 
Ibid., No. 4. 
Ibid., No. 10. 
Ibid., No. 13. 
Ibid., No. 14. 
Norddeutschen Kreidegebirges, p. 35, 1840. 
Charakteristik. Petref. Kreidegebirges, p. 91, 



Bujardin. 
Bujardin. 
Bujardin. 
Bujardin. 
Bujardin. 
Roemer. 
Geinitz. 
1842. 



330 



ECHINOCORYS. 



Ananchytes pyramidatus, PortlocJc. Rep. on Londonderry, p. 355, 1843. 

— OVATUS, Morris. Catal. of Brit. Fossils, p. 48, 1843. 

— coxoTDETTS, Morris. Ibid. 

— BEJtUSPBXRJCVS, Morris. Ibid. 



OTATA, 

OVATA, 

GIBBA, 
STRIATA, 

Gkavesii, 

SEMIGl.OBUS, 
CONICA, 



OVATA, 



GIBBA, 
STRIATA, 

Gravesii, 
semiglobus, 

CONICA, 
OVATA, 

GIBBA, 

Eudesii, 

STRIATA, 

Gravesii, 

CONICA, 

SEMIGLOBUS, 

OVATA, 



OVATA, 

echinocorys vulgaris, 

— papillosvs, 
Ananchytes ovatus, 
echinocorys vulgaris, 

Ananchytes ovata. 



Aoassi: et Desor. 
Affassic et Desor. 
Agassiz et Desor. 
Agassi: et Desor. 



Gravesii, 

GIBBA, 
STRIATA, 



Sismonda. Mena. Geo. -Zoologique, Mem. Accad. Torino, 

ser. ii, torn, vi, p. 353, 1844. 
Agassi: et Desor. Catal. raison. des Echinides ; Ann. 

Sc. Nat., 3 serie, t. viii,p. 2.9, 1847. 

Agassiz et Desor. Ibid., p. 30. 

Ibid. 

Ibid. 

Ibid. 

Ibid. 

Albin Gras. Oursins Poss. de I'lsere, p. 65, 1848. 
iTOrhigny. Prod, de Pal. Strat., No. 1 147, t. ii, p. 268, 

1850. 
d'Orligny. Ibid., No. 1 148. 
(T Orbigny. Ibid., No. 1 1 49. 
d'Orbigny. Ibid., No. 1 150. 
d' Orbigny. Ibid., No. 1152. 
d'Orbigny. Ibid., N. 1 154. 
Forbes. In Dixon, Geol. of Sussex, p. 341, 1850. 
Sorignet. Oursins de I'Eure, p. 71, No. 89, 1850. 
Sorignet. Ibid., No. 90. 
Sorignet. Ibid.,