^A'iY DORA ROGICK
R9GICK COLLECTION
1^ 7G. - ^ - )
M^moires de TAcad^mie Royale des Sciences et des Lettres de Danemark, Gopenhagne,
7™« serie, Section de8 Sciences, t. X, a" 1.
MARY DORA kUGICK
STUDIES
ON THE
CYCLOSTOMATA OPERCULATA
BY
G. M. R. LEVINSEN
WITH 7 PLATES AND 2 FIGURES IN THE TEXT
D. Kgi.. Danske Vidensk. Selsk. Skrifter, 7. R.ekke, naturv. og Ihathematisk Afd. X. 1
'•<>»3J«(c>-«-
ROGICK COLLECTION
K0BENHAVN HOVEUKOMMISSION^R: ANDR. FRED. H0ST & S0N, KGL. HOF-BOGHANDEL
BIANCO I.UNOS BOGTRYKKERI 1912
Prls: 4 Kr. 45 0re
I
Det Kgl. Danske Videnskabernes Selskabs Skrifter,
6*6 Rsekke. Naturyidenskabelig og mathematisk Afdeling.
Rr. 0re
I. med 42 Tavler, 1880—85 29. 50.
1. I'rjii, K. UiidersBgelser over Lysets Brydning i Dampe og tllsvarende Vaedsker. 1880 • 66.
i. Boas, J. E. V. SUidier over Decapodeines Slaeglskabsforhold. Med 7 Tavler. Resume eii fraiifais. 1880 8. 50.
3. Steenstrup, Jap, Sepiadarium og Idiosepius, to nye Sliegter af .Sepieines Faiiiilie. Med Bemairkiiiiiger om
to beslaegtede Former Sepioloidea D'Orb. og Spirula Lmk. Med 1 Tavle. Resume en frajieais. 1881 1. 35
4. Coldliig, A. Nogle Undersegelser over Slormen over Nord- og Mellem-Europa af 12'« — Hi^e Novb. 1872 og
over deii derved fremkaldte Vandflod i 08tersoen. Med 23 Planer og Kort. Resume en franfais. I88I 10. •
5. Uoas, J. E. V. Om en fossil Zebra-Form fra Brasiliens Campos. Med et Tillacg om lo Arter af .Sliegten
Hippldion. Med 2 Tavler. 1881 2. •
6. Steeii, A. Integration af en linear DitVerentialligning af anden Orden. 1882 50.
7. Krabbe, U. Nye Ridrag til Kundskab om Fuglenes Raendelorme. Med 2 Tavler. 1882 1. 35.
8. liaiinover, A. Den nienneskelige Hjerneskals Rygning ved Anencephalia og Misdannelsens Forhold til
HJerneskallens Primordialbrusk. Med 2 Tavler. Extrait el explication des planches en franfais. 1882 I. 60.
9. Den menneskelige Hjerneskals Rygning ved Cyclopia og Misdannelsens Forhold til Hjerneskallens
Primordialbrusk. Med 3 Tavler. Extrait et explic. des planches en franfais. 1884 4. 35.
10. Den menneskelige Hjerneskals Rygning ved Synolia og Misdannelsens I'orhold til Hjerneskallens Pri- mordialbrusk. Med 1 Tavle. Extrait et explic. des planches en franfais. 1884 1. 30.
11. Lehinanii, A. Forsog paa en Forklaring af Synsvinklens Indllydelse paa Upfattelsen af Lys og Farve ved
direkte Syn. Med 1 Tavle. Resume en franfais 1885 1. 85.
H, med 20 Tavler, 1881—86 20. ■•
t. Wanning, Eu^. Familien Podoslemaceae. 1^'° Afhandling. Med 6 Tavler. Resume et explic. des planches '
en franfais. ISSI 3. 15.
2. Lorenz, L. Om Melallernes Ledningsevne for Varme og Elektricltet. 1881 1. 30.
3. Warming, Eug. Familien Podostemaceae. 2''«° Afhandling. Med 9 Tavler. Resume et explic. des planches
en franfais. 1882 5. 30.
4. Chrlstensen, Odiu. Ridrag til Kundskab om Manganets liter. 1883 I. 10.
5. Lorenz, L. Farvespredningens Theori. 1883 60.
6. Gram, J. P. Undersegelser ang. Msengden af Primtal under en given Grsnse. Resume en franfais. 1884 4. •
7. Loreui, L. Restemmelse af Kviksalvsejiers elektriske Ledningsmodstande i absolut eleklromagnetisk
Maal. 1885 80.
8. Traustedt, M. P. A. Spolia Atlantica. Ridrag til Kundskab om Salperne. Med 2 Tavler. Explic. des
planches en franfais. 1885 3. »
9. Bohr, Cbr. Om lltens Afvlgelser fra den Royle-Mariotteske Lov ved lave Tryk. Med 1 Tavle. 1885 ... 1. »
10. Undersegelser over den af Rlodfarveslolfet optagne lUniajngde udferte ved Hja;lp af et nyt AbsorpUo-
meter. Med 2 Tavler. 1886 1. 70.
11. Thicif, T.N. Om Deflnitionerne fer Tallet, Talarterne og de tallignende Restemmelser. 1888 2. »
III, med 6 Tavler, 1885—86 16. •
1. Zeuthen, 11. C. Keglesnitslseren i Oldllden. 1885 10. •
2. Levlnseii, G. 111. R. Spolia Atlantica. Om nogle pelagiske Annulata. Med 1 Tavle. 1885 1. 10.
3. Hung, G. Selvregistrerende meteorologiske Instrumenter Med 1 Tavle. 1885 1. 10.
4. IHelnert, Fr. De eucephale Myggelarver. Med 4 dobb. Tavler. Resume el explic. des planches en
francais. 1886 6. 75.
IV, med 25 Tavler. 1886—88 21. 50.
1. Boas, J. E. T. Spolia Atlantica. Ridrag til Pteropodernes Morfologi og Systematik samt til Kundskaben om
deres geografiske Udbredelse. Med 8 Tavler. Resume en franfais. 1886 10. 50.
2. Lehmann, A. Om Anvendelsen af MIddclgradationernes Melode paa Lyssansen. Med I Tavle. 1886. ... 1. 50.
3. llannoTer, A. Primordialbrusken og dens Forbening i Truncus og Extremiteter hos Mennesket for Fed-
selen. Extrait en franfais. 1887 1. 60.
4. Lutken, Chr. Tillseg til ^Ridrag til Kundskab om Arterne af SIxgten Cyamus Latr. eller Hvallusene-.
Med 1 Tavle. Resume en franfais. 1887 60.
5. Fortsatte Ridrag til Kundskab om de arkliske Dybhavs-Tudsefiske, siErligt SliBgteu Hiinantolophus.
Med 1 Tavle. Resume en franfais. 1887 ■ 75.
6.. Kritiske Studier over nogle Tandhvaler af Slaegterne Tursiops, Orca og Lafjenorliijnchus. Med 2
Tavler. Resume en francais 1887 4 75.
7. Roefofd, E. Studier i Plalosoforbindelser. 1888 1. 30.
8. Warming, Eug. Familien Podostemaceae. 3<"^ Afhandling. Med 12 Tavler. Resume et explic. des planches
en franfais. 1888 6. 45.
V, med 11 Tavler og 1 Kort. 1889—91 15. 50.
i. Lutken, Chr. Spolia Atlantica. Ridrag til Kundskab om de Ire pelagiske Tandhval-JJaegter Steno, Del-
pliinna og Truddplnnnti. Med 1 Tavle og 1 Kort. Resume en franfais. 1889 2. 75.
2. Talenllner, D. De endelige Transformations-Cruppers Theori. liesunie en franfais. 1889 5. 50.
3. Hansen, U.J. Cirolanidx ct familiie nonnullx propinqua: Musci llauniensis. Et Ridrag til Kundskaben
om nogle I'amilier af isopode Krebsdyr. Med 10 Kobbertavler. Resume en franfais. 1890 9 SO.
4. Lereui, L. Analytlske Undersegelser over PrinUalma;ngderne. 1891 • 75.-
(Forl83ttes paa Omslagets S. 3.)
MARY DORA ROGICK
STUDIES
ON THE
CYCLOSTOMATA OPERCULATA
BY
G. M. R. LEVINSEN
WITH 7 PLATES AND 2 FIGURES IN THE TEXT
D. Kgi,. Danskk Vidensk. Selsk. Skhii- teh, 7. R^kke, naturv. or, mathematisk Afd. X. 1
•^X-SJUcS-.
K0BENHAVN
HOVEDKOMMISSION.EK: ANDR, FRED, H0ST&S0N, KGL. HOF-BOGHANDEL
BIANCO LUNOS BOGTRYKKERI 1912
PKEFACE.
Ma,„
ly years ago I undertook a study of the Danish cretaceous Brijozoa the results of which have not yet been pubiislied, and among the species studied by me were also a small number belonging to the family Melicerititidae (Eleidae d'Orb.) to the members of which d'Orbigny ascribes a calcareous operculum the presence of which, however, has been denied by all the later authors who interprete the supposed operculum as a closure-plate of the same nature as that which has been found both in the Cijclostomata and the Cheilostoinata. I came however to the result that d'Orbigny was right in his interpretation of the named structure, and I have published some remarks on this subject in my preliminary communication sStudies on Bryozoa« '). As later I wished to make a more comprehensive study of this interesting group I extended my investigations over a number of foreign species, and in this etTort I have been supported by several colleagues abroad. In the first instance I owe a debt of gratitude to Dr. F. Canu the author of so many valuable works on fossil Bryozoa, who has not only sent to me a large number of French species defined by him, but also helped me to acquire materials containing cretaceous bryozoa from a number of French localities. A similar material from a few other French localities has been sent me by Mr. G. Dollfus, and to Mr. M. FiLiozAT who has made a special study of the cretaceous Bryozoa from Vendome I owe the possession of a number of species from that locality. For the gift or loan of specimens I am also indebted to Mr. A. W. Waters, Dr. E. Pergens, Prof. Dr. G. Steinmann, Bonn and Prof. Dr. H. Wegner, Miinster, and lastly I have been able to acquire a collection of cretaceous Bryozoa from the Chatham chalk, by the aid of Mr. W. Gamble. To all these gentlemen I offer my sincere thanks.
Zoological Museum of Copenhagen. /"* A/T R T
August 16, 1912. ^- "^- ^- •L'EVINSEN.
16.
Historical Introduction.
GoLDFuss ') was the first author, who described a species belonging to this di- vision namely Ceriopora gracilis while the first genus Meliceritites has been instituted by RoEMER ^) for the three species Mel. gracilis (Goldf), Mel. Roemeri (Hag) and Mel. porosa Roemer. The name Meliceritites is derived from Melicerita, a genus founded by Milne Edwards'') for a fossil species of the present genus Celliilaria (Cellaria), Cel. Charlesworthii, and the main character upon which the genus was founded is the arrangement of the zooecia in continuous transverse series, a character which at the present state of systematic knowledge cannot be regarded as sufficient for the institution of a genus, and therefore the name Melicerita must be regarded only as a synonym to Cellularia. Roemer's genus is defined in the following manner: »Runde Slamme deren sechsseitige Zellen mit einer Ecke und nicht wie bei alien bisher beschriebenen Arten, mit einer Seite nach oben gerichtet sind und die gemein- schaftliche Scheidewand zweier Zellen der hoheren Reihe tragend«. After this de- finition he adds the following apparently contradictory information: »Gleiche Zellenbildung findet sich auch bei Eschara und hat Milne Edwards hier darauf die Gattung Melicerita gegrundet«. As stated above however it is not the form of the zooecial areas but the arrangement of them in transverse series which has induced Milne Edwards to found a new genus for this species. It is easy to understand that Roemer has derived the name of his new genus from Melicerita as the three species described by him agree with Mel. Charlesworthii in the possession of rhom- bic-hexagonal concave zooecial areas, surrounded by distinct ridges and, besides, arranged in transverse series, and as he has not seen the long tubular pari of the zooecia hidden within the colony his only motive to divide Meliceritites from Meli- cerita seems to be the different form of the colony, which in the latter is a two- layered plate while in the former it is ramose with rounded branches.
V. Hagenow ') is the first author who refers these forms to a special division which he named Salpingina and characterized in the following manner: »Ange- wachsene verastelte Polypenstocke, mit langen Rohrenzellen, welche sich kurz vor der Miindung trompetenartig, fast sackformig erweitern, und ausserlich mil einer kalkigen oder hornagtigen Membran verschlossen sind. In dieser Meinbran befindet sich die kleine, verschieden gestaltete Miindung, die warscheinlich bei Allen mit einer Klappe versehen war und die bei einigen Arten noch erhalten ist.< At another place he names this >Klappe« operculum: vEin Operculum ist bei Einigen, vielleicht bei Allen vorhanden«. To this division he refers the two genera Escharites and Inversaria the former of which also comprises Roemer's Meliceritites. Apart from the circumstance
») 1. p. 35, pi. X, figs 11 a— c. ■-') 6, p. 18, pi. V, fig. 13. "■) 2, p. 34.5, pi. 12, (ig. 19. *) 5. p. 55.
that Hagenow's division only embraces freely growing species it is founded on the examination of a few badly conserved species of which only a single Eschariles gra- cilis with certainty can be referred to the Eleidce, and as species belonging to this division have never been found in the tertiary formation the following statement of the author distinctly shows that his Salpingina also embraces common cyclosto- matous species: Alle sind fossil und gehoren dem Jura, der Kreide und der Ter- tiarbildung an«.
The presence of an operculum in the Salpingina should be a real difference from the Cgclostomaia, but there is no evidence that the author has seen a real operculum in any of the species referred by him to this division. As a species provided with such an operculum he names Escharites fFeliceaJ velata Hag., but this species belongs to quite another division, the Ceidae, which are not provided with an operculum, and what Hagenow has seen is only a closure-plate.
d'Orbigny ') in 1852 founded a division to which he gives the name Centri- fagines operculines and which he defines as follows: » Cellule centrifuginee toujours pourvue d'un opercule. Colonic tres variable dans sa forme composee de cellules generalement pen saillantes, mais toujours pourvues d'un opercule: partie testacee ou calcaire, s'ouvrant comma une porta pour laisser sortir I'animal*. As to the operculum he later adds: >>D'ailleurs s'il pouvait encore rester quelques doutes a cet egard la presence de ces opercules encore restes en place dans beaucoup d'es- peces fossiles, vient entierement les lever et donner la preuve que cet opercule exi- stait«. To this division d'Orbigny refers two families, the Eleidae and the Myrio- zoumidae, the last of which contains the exstinct genus Foricnla and the recent genus Myriozoum. The last named genus, however, belongs to the Cheilostomata. The above quotation leaves no doubt that d'Orbigny has founded his division Eleidae on the presence of an operculum, and it is a curious fact that all the modern authors with the exception of the present though accepting this division, at the same time deny that its member possesses an operculum, explaining the calcareous plate which may be found closing the aperture of more or less zooecia as a closure-plate. Not a single author even mentions this statement of d'Orbigny.
Hamm "') in 1881, founded a very artificial division, the S/!(///!fl/o/)or(;!« to which he besides two inoperculate cyclostomatous genera Stiginatopora Hamm {-Hanimia Grey) and Cyrtopora Hag. also referred the operculate genus Melicerilites. He characterizes this division as follows: > Die Zellen sind ahnlich wie die der Tubuliporiden beschaffen. Statt dass sie aber in der mitlleren Axe des Slammes entspringen legen sie sich rings um ein senkrecht stehendes, im Querschnitt rundliches Biindel von langen cylindrischen unter einander parallelen R6hren«. He divides the Stigmatoporina in two groups the second of which (Melicerititesjhe characterizes by the trumpet-shaped distal enlargement of the zo- oecia: ». . zweitens in solche, deren Zellen lang, anfangs sehr dunn sind und erst an der Mundung sich plotzlich trompetenforinig erwaitern«. As we have seen Hagenow has al-
») 7, p. 605. '-] 8, p. 45,
ready used this character for his Salpingina, but Hamm has overlooked that the nar- row tubes of the axial bundle are only the proximal parts of the zooecia, and as we shall see later, this error is repeated tjy Mahsson. As to the operculum spoken of by d'Orbigny he expresses the following opinion'): »Dieser Deckel ist indesscn kein deni beweglichen Deckel der chiloslomen Bryozoen analoges Organ, sondern eine einfache Kalkwand, mittelst deren sich das Thier bei zunehmendem Alter oder uni sich gegen aussere Einlliisse zu schutzen, in die Zelle einkapselt; er ist also ein blosses biologisches Produkt. Dem entsprechend findel sich derselbe nicht nur bei den Opercules von d'Ohbigny, sondern ebenso bei den Clausidae D'Orbg., Diaslo- pora, Terebellaria, Osculipora, Heleropora etc. also bei Formen von sehr verschiede ner Natur. Zur Systematik darf er daher nicht verwendet werden«.
Marsson"), in 1888, united the Ceidea and the Eleidea into a division Metopopo- rina, and the Eleidea he characterized as follows: >. . . . die Hauplzellen bei den cylindrischen Arten auf der Aussenseite eines centralen cylindrischen Biindels langer, Rohrenzellen entspringend, (ob audi bei den llachen, blattartigen Formen die Haupt- zellen aus einer Schichl von Nebenzellen entspringen, bedarf einer weiteren Unter- suchung), auf der Oberllache des Stocks dicht an einauder gedrjingt, mit melir oder weniger rhombisch-sechseckigen Stirnseiten ausmiindend, die im vorderen Theile eine dreiseitige Miindung tragen«. In the diagnose of Melicertites he mentions the trumpet-shaped expansion ,of the zooecia, and the manner in which he speaks about the operculum seems to show that he inlerpretcs it as a preliminary calcareous co- vering which later disappears: sMiindung .... anfangs durch eine Kalkmembran geschlossen und mehr hervortretend <.
Pergens ') in 1890, separated the two groups, the Ceidae and the Eleidae, united by Marsson in his Metopoporina, and the latter of them, to which he gives the name Melicertitina he defines in the following manner: »Les zoecies se dilatent vers I'extremile en forme de trompelle; Torifice n'occupe qu'une partie du dianietre trans- versal des zoecies et est situe a leur partie distale. Les ovicelles soul situees a I'in- terieur des colonies, entre les zoecies, ou occupant leur place, et communiquant avec I'exterieur par une ouverture triangulaire a base proximale et a pointe plus ou moins allongee«. The slructures which Pergens as d'Orbigny and Marsson re- gards as ovicells are as Waters has pointed out very like the Cheilostomalous avi- cularia, and the real gonozoocia have not been seen by Pergens, who, besides, speaks about Ihe supposed ovicells as if there were two differenl kinds, some placed within the colony and others taking the place of zooecia. This however is not the case. Pergens as Hamm and Marsson means that the zooecia of Meliceritites take their origin from a central bundle of narrow tubes, and like these authors he also denies the presence of a real operculum*): »les Opercules renferment deux families: les MyriozoLimidd' et les Eleidce. Le tj'pe de la premiere est reellement pourvu d'un opercule, c'est done un Cheilostome; les secondes n'ont ])as d'opercule, mais souvent
8, p. 9. 2, 10, p. 45. ■') 9, pp. 325, 391, ') 9. P- 320,
une membrane calcareuse transversale, caractere qu'elles partagent avec des Hetero- pora, des Entalophora et une quantite d'autres genres. —
Waters') who was the first to point out the likeness between the »cellules accessoires« or »cellules ovariennes« of d'Orbigny and the Clieilostoniatous avicu- laria is inclined to think, that the Eleidae have been provided with a chilinous operculum. He says about that, referring to transverse sections o{ Meliceritites Roy ana: »In transverse sections (figs 5 and 11) a contraction formed by a curved plate is seen on each side just below the opening. Possibly an operculum has an attachment here, but of this I have not been able to satisfy myself«. He does not mention d'Orhigny's calcareous opercula, and, therefore, no doubt regards them in the same way as the other authors, namely as closure-plates. On the whole Waters seems inclined to think that the Eleida; are nearer related to the Clieilostomata than to the Cyclostomata.
Gregory-) who regards the Eleidae only as a family of his suborder Cyclosto- mata lubulata defines this family as follows: »Cyclostomata tubulata in which the
') 12, p. 48, pi. VI.
2) Gregory (14, p. 285) wlien speaking about d'Orbigny's institution of the family £/cidachas quite misunderstood this author. He says as follows: »D'Orbigny founded this family in 1853 for a series of Bryozoa with anomalous characters, of which the most striking was the presence of a series of modified zoiecia that he described as ^cellules accessoires<. These accessory structures are of two types, large superficial marsupial chambers, and cells with triangular or elongated apertures and a platform iiarallel to the surface of the zoarium. The marsupial chambers were described by d'Orbigny as Dcellules ovariennes's and they are clearly gono- cysts or gontecia. The nature of the second set is more important. D'Orbigny recognized that they sometimes occur on the same specimen as »cellules ovariennes«, and therefore cannot be ovarian. He suggested that they may be male cells or sperm-cells. Nevertheless Pergens and Marsson subsequently described them as ovicells . Every reader nuist understand the above statement in that manner 1) that r/ORBioNv has founded the family Eleidae chiefly on account of its possessing modified zooecia (licellules accessoiresi), and that he has only found such modified zooecia in the Eleidae. Further 2) that d'Orbigny has pointed out the pre- sence of marsupial chambers (gonozoa?cia) in the Eleidae, and 3) that he has interpreted some of the modified zotecia found in the Eleidae as „cellules males". As to the first ])ointthe above quotation of d'Orbigny shows that he has founded tfie division Centrifitgines opcrciilincs not on account of its [)Ossessing modified zooecia, but because it possessed calcareous opercula. and for i)oth the families belonging to tliis division he only mentions in somewhat different terms that they sometimes possess cellules accessoires* which structures, besides, he has found not only in this division, but also in the Cheilostomata and the Cyclostomata. As to the two other points d'Orbigny has nowhere mentioned or pictured an Eleid gonozosecium, and what he says about , cellules m;tles" only concerns the Cheilostomata. The structure of the avicularia be- ing at that time unknown d'Orbigny is evidently most inclined to look upon the modified zo- oecia as gonozotecia (»cellules ovariennes«), but as in Eschara') they are found together with zooecia wearing ooecia he cannot escape regarding the latter as »cellules ovariennes<, a view held further by all his i)redccessors, and therefore he asks whether they may not liere be regarded as DCellules m;iles«. In the representation he gives of the linjozoaires centrifutjines, a division which besides some C<e;!0«/onia<a comprises the present Cyclostomata. the Eleidae, the Myriozoumidae and the Ceidae, he says aliout tliese modified zooecia'-): Uans quelques genres
7, p. 99. ■) 7, p. 587.
apertures are lateral and siibtemiinal, and which frequently have avicularia and spines. The marsupial chambers are gonocysts or gonoecia. Many of the zooecia may be closed by thin calcareous films«. The author here uses the term »lateral« in quite an unusual waj'; namely as a synonym to »subterminal«, and when he speaks about »spines« he no doubt means the small projections which in many species are found where three dividing ridges meet each other, and which by other authors have been called »tubercles«. However, he only uses this expression in the family diagnose, and nowhere in the descriptions of the single species. Gregory distin- guishes between gonocysts and gonoecia, and as gonocysts he designates the pyriform greatly enlarged gonozooecia which are provided with a small terminal aperture. He ascribes gonoecia to the genus Nodelea, but in N. durobrivensis he has found a gonocyst, and the gonoecium which he ascribes to N. semihina is really an avicu- larium. To the genus Foriciila he ascribes »a gona3cium or gonocyst«, but the piri- form gonaecium (? gonocyst), which he assigns to F. pyrenaica is also an aviculari- um. He is inclined to think that the Eleidae have been provided with chitinous opercula, and the calcareous plates which in so many zooecia cover the aperture he interpretes in the same manner as his predecessors, namely as closure-plates.
The present author'), in 1902, in a preliminary paper expresses the view that d'Orbigny has been right in ascribing opercula to the Eleidae at the same lime pointing out the difference between the operculum and the closure-plate.
Lang'-), in 1906, distinguishes between »closed zooecia and normal zooecia« and uses the presence or absence, the frequence or rarity of the former as a specific character. He says about the closed zooecia: »Like the avicularia their physio- logical significance is a matter of conjectures.
The Morphology.
The Zooecia.
The zooecia^) have essentially the same form and structure as those of the Cy- clostomata being very long slender tubes, each of which rises from the proximal
nous voyons, mais tres-rarement, des cellules differentes des aiitres, beaucoui) plus grandes, et que nous regardons ici comuie des cellules ovariennes servant a la reproduction des oeufs (1)1. 73'), 73(), 741, 761, 777). Quelques genres seulemcnt oflrent do verital)Ies vesicules ovariennes distinctes des cellules et placees du cote oppose, destinees aussi a produire les oeul's (pi. 770). While the cellules ovariennes pictured in pi. 761,770 and 777 (belonging to MuUisparsa Luciana, Hornera lichenoides and Beptomuliisparsa diluuiana) are real cyclostomatous ooecia those figured in pi. 735, 736 and 741 are Eleid avicularia*. To Gregory, therefore, is due the credit of being the first author who has found gonozotecia in llie Eleidae.
') 16, p. 28. ■^) 19.
') In the descriptions of the species the names „zooecia", „lieterozooecia" and „kenozooecia" are used to designate that part of tlie named zooids, which is visible in the surface of the colony.
9
part of another tube, and only appearing on the surface of the colony with their distal parts, but while in most Cyclostomata the distal part of each zooecium keeps its character as a narrow cylindrical tube whether it projects with a shorter or longer free end or only with its frontal convex surface, I have hitherto only found this to be the case in a single species of this division, namely in Meliceritites Doll- fussi Perg. (pi. IV, fig. 23, pi. V, figs. 9, 10.) in which the zooecia are provided with a shorter or longer freely projecting terminal part. As a rule the superficial or ter- minal part of the zooecia enlarges into a rather broad hexagonal, rhombic or qva- drangular area, the zooecial area, and the single areas are in most cases divided from each other by a meshwork of distinct ridges. These areas are very much like those found in the coilostegous Cheilostomata, for inst. in Ongchocella, Micropora, Membranicellaria and Cellnhtria (Cellaria), and Roemer") therefore says: »Gleiche Zellenbildung findet sich auch bei Escharwi. The greatest likeness these areas show to those found in the genus Cellularia as has been pointed out in the historical in- troduction, but this likeness is a quite superficial one as in this genus the meshwork of ridges has nothing to do with the dividing walls and do not correspond to the single zooecia which have a quite dilTerent form=). hi the Melicerlitidae contrary the ridges are the edges of the walls dividing the single zooecial areas which may easily be seen by grinding away a part of the surface of the colony, there being left a system of hollows corresponding in size to the single areas. This meshwork of ridges which is only absent in some species presenting a convex surface, f. inst. in Meliceritites micropora (pi. Ill, fig. 10), is very often in the points of intersection l)rovided with more or less prominent tubercles the presence and development of which is dependent on the manner in which the concave surfaces of the zooecial areas join the marginal ridges. The more the transition of the surface into the ridge is a gradual one the more developed are the tubercles (pi. II, figs. 10, 11,23, pi. Ill, fig. 17) while on the contrary they are feebly developed or quite lacking in such species (pi. Ill, fig. 20, pi. V, figs. 1, 7, 9, 12.) where the ridge is more distinctly defined from the surface. While two contiguous concave surfaces gradually rising towards each other must form a roof-shaped ridge, three or four must where they meet, form a pyramid, but only in a few cases the single surfaces of these pyramids are distinctly defined (pi. V, fig. 19.) being generally rounded. In the circumference of an hexagonal area (pi. II, fig. 11) there can be found six tubercles three of which may be called »praeoral« being placed immediately distally to an aperture while the other three each of which has its place between two apertures may be called »interoral«. When the zooecial areas are rhombic there can only be found prseoral tubercles.
While concave or saddle-shaped zooecial areas surrounded by distinct ridges and sometimes provided with more or less distinct tubercles are also present in a number of cyclostomatous species, f. inst. in Peripora pseadospiralis Mich., Spiropora
') 6, p. 18. ■-) 18, p. 209— 212, pis. VII VIU.
n. Ev, I) Vidensk. Selsk. Skr., 7. R:ukke. naturvidensU. og mathem. Afd. X. 1.
10
macropora d'Orb. Entalopbora ramosissima d'Orb. nnd Enf. madreporacca Goldf., the Me/ jferjViVidae always seem to show a distinct dilTerence from the Cyclostoniata tlierein that the zooecial tube the larger part of which is very narrow possesses a great and rather sudden distal enlargement while in the Cyclostoniata the much wider zooecial tube only gradually widens distally without attaining the great distal enlargement. A transverse section of a cycloslomatous colony therefore shows a number of hol- lows gradually increasing in size from within outwards, (pi. VII, ligs. 24, 25), while a corresponding section of a Meliceritites distinctly shows a contrast between numerous inner very small hollows and a single or double outer circle or series of much larger ones (pi. VII, figs. 10, 19, 23, 30). We see from these transverse sections that the above enlargement takes place especially in the direction from within outwards, and its presence in the Melicerititidae may possibly be explained from the fact that they have possessed an operculum, and a calcareous too, the re- lative great weight of which must have required strong occlusor muscles. We have seen in the historical introduction that Hamm, Hagenow, Marsson and Pergens use the trumpel-shaped enlargement of the zooecia in the Eleidae as a systematic character. d'Orrigny does not mention it, but in his work he has given numerous figures of transverse sections which distinctly show the above contrast between the Cyclostomata and the Melicerititidae.
The aperture is placed in the distal part of the zooecium which in many spe- cies is more or less protruding. It is always provided with a straight or almost straight pi'oximal margin, and the two lateral margins which are in most cases more or less convex, more seldom somewhat incurved (pi. II, lig. 23.) or almost straight, either run together in a distal curve or form a distal angle (pi. II, figs. 1, 23, pi. IV, fig. 22). It takes up a greater or smaller part of the zooecial area, which in a few species (pi. VI, figs. 12, 13, pi. VII, fig. 4) it almost fills, the suboral part of the area being very small. The aperture is in most species surrounded by a more or less developed peristomial thickening a greater or smaller distal part of which is formed by the marginal ridge but in many cases the proximal part of this thicke- ning may be absent or only developed in old zooecia. Sometimes the apertures of contiguous zooecia are divided from each other by broad pillar-like swellings, re- presenting both the dividing ridge, the lateral parts of the peristomial thickening (pi. II, fig. 11). and sometimes also the interoral tubercle (pi. Ill, fig. 18). The prseoral tubercle is not rarely developed in the shape of a beak-like projection (pi. I, figs. 1, 2, pi. V, figs. 3, 4, pi. VI, fig. 13). We have seen in the historical introduction that d'Orbigny characterizes this division by the presence of a calcareous operculum while all the later authors interpret d'ORBiGNv's operculum as a closure-plate. Some of these authors, however, think that these forms have possessed a chilinous operculum, and the presence of an operculum seems, besides, to be a natural con- sequence of the assumption, that certain individuals of the colony must be explai- ned as avicularia an avicularium being a modified zooecium provided with a strongly developed and modified operculum. There can be no doubt that d'Orbigny is right
11
ill liis interpretation of the named calcareous plate. The operculum is an arched calcareous plate provided with more or less distinct radiating strife starting from the middle of the proximal margin, and in contrast to the closure-plate found in all the species examined it shows a distinct free margin, while the closure-plate is soldered together with the margin of the aperture, being really a growth starting from this margin and gradually extending over the aperture. Sometimes may be found closure-plates the middle part of which is not yet closed (pi. IV, fig. 6, 15). The very presence of the radiating striae in the operculum is suflicient to show that we have here to do with an independent structure and not with a closure- plate, as such striae which we f. inst. know from the zooecia of the Cheilostomata indicate that the calcification has taken place in radiating belts. At a time when the operculum was still in a membranous state, the calcification therefore started from the middle of the proximal margin and extended in radiating belts gradually outwards and distally. As the other calcareous surfaces the operculum shows a number of more or less distinct pores which in some species are disposed in two distally converging series (pi. I, lig. 1), while in others they are placed in the ends of small claviform projections whicli show a flabelliform arrangement (pi. 1, fig. 11). In Melic. iindala the operculum shows a number of 1 — 4 curved impressions (pi. IV, fig. 11, 12, 16). The operculum fits into the aperture in two different manners. In a number of species the margin of the aperture is in the same manner as a door- frame or a window-frame provided with a more or less developed depression, the "oral ledge" decreasing in breadth towards the proximal margin and destined to support the margin of the operculum, when the zooecium is closed (pi. I, fig. 13; pi. Ill, figs. 10, 11, 23; pi. IV, figs. 18, 22) while in other species the margin of the aperture is only obliquely sloping inwards. The difference between these two cases, however, is not always easy to see, especially when the state of preservation is not, good. — As in most Cyclostomata the zooecial areas as well as the other surfaces are provided with numerous fine pores, but in a few species the pores are only to be found in the opercula, being in the zooecial and heterozooecial areas replaced by more or less numerous pits {Melic. punctata, Melic. pyrenaica).
, The Heterozooecia.
d'Orbigny is the first author who has described and pictured the heterozooecia of the Melicerititidae, which he designates as "cellules accessoires" or 'cellules ovariennes" the two terms being generally used by him as synonyms.
While Marsson and Pergens still look upon these individuals in the same manner as d'Orbigny, namely as gonozooecia Waters is of the o|iinion that they must be regarded as avicularia, and this view has been followed by the later authors. Canu names them "eleocellaires".
The heterozooecia consist as the zooecia of a long narrow tubiform part hidden within the colony and a superficial part, the heterozooecial area, which is more or
12
less different from the zooecial area, the aperture being especially of another form or of another size than the zooecial aperture. As a rule it is more elongate, and very often much larger, but in some cases it is much smaller and at the same time of a quite similar form. At the whole there is seen similar differences in the form of the aperture as are found in the avicularia of the Cheilostomata. The simplest form of heterozooecia is found f. inst. in Mel. angulosa (pi. II, figs. 8, 10), Mel. Dollfusi (pi. IV, fig. 23), Mel. sarissata (pi. II, fig. 1), Mel. punctata (pi. V, fig. 7) and Mel. hexagona (pi. V, fig. 3). In the aperture there may be discerned between the proximally situated "inner aperture" distally limited by a curved or angularly bent line and a generally larger or longer distal concave portion, which corresponds to the "oral ledge" of the zooecial aperture, and therefore must be designated in the same manner.
A sagittal section through a heterozooecium shows that the presence of this di- stinctly bounded oral ledge is due to the circumstance that the inner distal surface of the zooecial tube suddenly alters its direction forming an obtuse angle with the proximally situated part, and the edge thus formed just makes the distal boundary line of the inner aperture. In the heterozooecia of Mel. Filiozaii n. sp. (pi. VI, figs. 7, 9) and Mel. sqvamata (pi. V, figs. 14—16), and in the large heterozooecium of Mel. Roemeri (pi. V, fig. 18) the oral ledge consists of a deeper median part and two more or less developed lateral thickenings while in a larger number of species f. inst. in Mel. magnifica (pi. 1, figs. 3 — 5,7), Mel. lamellosa, Mel. pentagoniiin (pi- IV, fig. 22) and Mel. gothica (pi. II, fig. 24) these thickenings have been developed into two inwards sloping triangular processes, the "lateral processes" which conceal the larger part of the oral ledge and the inner aperture.
The thickness of these two processes (pi. 1, fig. 10) which may be coherent distally decreases towards the median line where they are divided from each other by a more or less narrow longitudinal fissure their free proximal margin being divided by a transverse fissure from the distal margin of the suboral area. When the state of preservation is not good the outer boundary of the two processes is riot distinct, and the opening formed by the two fissures may be taken as the space once filled by the mandible. The aperture in all the species of this group is of an elongate triangular form. A fourth group of heterozooecia which have been found in Mel. Steensimpi (pi. Ill, figs. 11, 12), Mel. Canui n. sp. (pi. Ill, figs. 19—27), Mel. diirohrivensis (pi. IV, figs. 1-4) and Mel. Roemeri (pi. V, figs. 21 — 24) have that in common with the first mentioned, that the aperture lacks both lateral thickenings and lateral processes but these apertures have a form very like to or at least not very different from the zooecial aperture, and most of them are, moreover, much smaller than the latter. Also the heterozooecia themselves are as a rule much smaller than the zooecia, and the smallest heterozooecia found in Mel. durobriuensis only attain the sixth part of the length of the zooecia. A few of the heterozooecia found in Mel. Cnnui have the apertures provided with a comparatively narrow oral ledge, but as a rule the latter takes up the larger part of the aperture and is per-
13
forated either with a small rounded or with a narrow triangular or fissure-like opening. While the form of the apertures is constant in Mel. dnrohrivensis and Mel.Steenstrupi, in Mel.Caniii and Mel. Roemeri it is subject to a rather great varia- tion both as to form and size, and in the latter species the largest of them are ligulate and stretched beyond the distal angulale border of the zooecium. In Mel. durobrivensis these heterozooecia are found not only interspersed among the zooecia, but also constituting an incrusting base (pi. IV, fig. 19), and they seem here to play a similar role as the corresponding kenozooecia of a Re/e/jora-colony ').
In most species 1 have found the aperture of more or less heterozooecia closed by a calcareous mandible (pi. I, figs. 1, 2; pi. II, figs. 3, 16, 18; pi. Ill, figs. 3, 20; pi. IV, figs. 1,23; pi. V, figs. 5, 8, 17; pi. VI, fig. 2) which has a similar arched surface as the opercula and often shows more or less distinct radiating strife. Sometimes it is as many mandibles of cheilostomatous avicularia provided with a hooked beak, being at the same lime strongly arched not only from side to side but also proximally distally (pi. II, fig. 3).
In .1/e/. Canui and Mel. durobrivensis the semi-elliptical mandible is provided with distinct radiating strise, and chiefly differs from the zooecial operculum in being much smaller. Lastly it might be of interest to compare these heterozooecia with those found in the Cheilostomata, and in ordre to make the difference between them more conspicuous we shall choose for comparison such presenting a maxi- mum of outer likeness, f. inst. those found in a Thalamoporella-species') and in Mel. angiilosa (pi. 11). Besides the likeness in the form of the aperture we may in both discern between an inner aperture and a distal concavity, but while the latter in Meliceritites is the distal inner surface of the zooecial tube it is in Thalamopo- rella formed by a free lamina (a cryptocyst) which rises from the lateral and the distal walls within the free margin. Besides the difference which the heterozooecia of the Meliceritidae show from those of the Cheilostomata in being long slender tubes the greatest part of which is hidden within the colony they present another con- stant difference from the latter therein that the aperture is always limited by a continuous calcified frame while in the Cheilostomata it is limited proximally by a membranous area of different extent. The group of heterozooecia above spoken of in which the larger part of the original aperture .has been concealed by two triangular laminte shows a certain likeness to the heterozooecia of certain species of Onychocella'') and Rhagasostoma in which the cryptocyst lamina has attained its greatest development, being only provided with a small perforation for the occlusor muscles, but the two laminae are two thick processes from the lateral parts of the oral ledge, and the two mutually vertical fissures which may be compared to the perforation in the avicularia of Oinjchocella and Rhagasostoma belong both to the opercular area while the proximal part of the latter perforation is placed within the suboral area. Lastlv we shall remind of the different structure of the mandibles.
') 18, p. 290. pi. X. -') 18, pi. Via. ') 7, pi 673, figs. 1. 4,
14
In opposition to the Cheilostomata in which lieterozooecia may also arise by a process of budding from the surface of tlie zooecia (dependent helerozooecia) tlie Melicerititidae only possess indejjendent heterozooecia, and it is therefore a mistake when Gregory in Foriciila aspera^) interprets a pair of long narrow pits seated on each side of the aperture as avicularia.
As a result of the above comparison I must agree with the opinion set forth by Gregory^) that the avicularia in both divisions have developed independently, and therefore are only parallel, not homologous structures.
The Kenozooecia.
Kenozooecia or bryozoids without an aperture (dactylelhrae Greg) have been found in 12 of the 31 species examined. As a rule they have the same form and size as the zooecia, but as they lack an aperture they are provided with a uniform flat or concave frontal area within the marginal ridges. In Mel. Steenstriipi they are exceptionally much smaller than the zooezia. They are generally found inter- spersed among the zooecia (pi. VI, fig. 19) in greater or smaller numbers, but in a few species they take up together with a number of heterozooecia either the whole "dorsal" surface or a large pari of it (pi. Ill, figs. 11, 14), and at the whole they are in most cases accompanied by heterozooecia, whether they appear in groups among the zooecia or take up a large part of the surface of the colony.
The Gonozooecia.
The gonozooecia (pi. VII) which have hitherto only been found in a small number of the species examined are zooecia provided with a large (1 — 2 mm. long), more or less convex terminal expansion, an ooecium which in most cases has a pyriform outline, but in the same species, nay in the same colony the form may be subject to great variation, being sometimes roundedly triangular, sometimes ovate or even circular. The distal end of the ooecium is provided with a trans- versely ovate, somewhat infundibuliform, fronlally directed ajjerlure, and proxi- mally it generally ends in a shorter or longer tail-shaped process. When the thick porous frontal wall is removed, the flat or somewhat concave inner wall in most of the ooecia examined presents a uniform smooth surface which is only inter- rupted at the boundary between the caudal process and the rest of the cavity by a rhombic zooecial area surrounded by prominent lidges and closed by a concave calcareous film. Distally to this area which no doubt belongs to the gonozooecium may sometimes be seen a few more or less indistinct rhombic impressions of the same form and si/e as the zooecial areas, and when the inner wall of the ooecium has been dissolved by the use of strongly diluted acid, there appears a mosaic of rhombic zooecial areas each of which is closed by a concave calcareous film.
') 14, p. 358 -'t U, p. 288.
15
In the ooecia of Mel. lamellosa (pi. VII, figs. 20—22) however, only a few zooecial areas are seen in the proximal part while in the rest of the cavity the zooecia are only represented by a number of more or less open tubes. In opposition to the ooecium of Mel. magnifica figured in Pi. VII, fig. 14, in which the inner wall has covered a number of undeveloped zooecia and heterozooecia I have found an- other small ooecium of the same species in which the corresponding individuals are provided with completely developed apertures. Also the gonozooecium the larger part of which is seen proximally to the tail-shaped process of the ooecium is provided with a completely developed aperture. A third difTerenl case I have found in a number of open ooecia belonging to the same species, all of which were placed not far from the growing edge in a superficial layer of growth (pi. VII, fig. 17). Here there projects in the proximal part of the ooecium a number of zooecia and heterozooecia of very different development while the rest of the inner wall presents a uniform smooth surface, the dissolution of which by the use of diluted acid denudes a layer of completely developed zooecia and heterozooecia belonging to an older part of the colony. In the ooecium figured in PI. VII, fig. 17 there is seen in the proximal part a number of open zooecial areas, and the gono- zooecium is in the same state of development, while that figured in fig. 18 shows a number of almost completely developed zooecia and heterozooecia. Proximally to the latter is seen a small triangularly rounded aperture, but the lail-shaped pro- cess seems to have been broken off.
By the aid of the above facts we may form the following picture of the devel- opment of the ooecia. When the gonozooecium begins to expand into the ooecium the inner wall of the latter covers a number of more or less developed zooids, which of course get chequed in their development while the adjacent zooids are able to continue their growth, which explains that the lateral margins of the ooecia are partly covered by a number of zooecia and heterozooecia. When the gono- zooecium belongs to a superficial layer of growth and is placed near to the growing edge, the ooecium first covers the undeveloped zooids placed distally to the gono- zooecium and thereafter a number of zooids belonging to the older part of the colony. The presence of freely prominent zooids in the proximal pait of the ooecium must no doubt be explained in that manner that they have originally been covered by a bulging part of the inner wall of the ooecium, which has later been destroyed. A curious fact is the ditl'erent state of development shown by the gono- zooecia even in the same species.
The aperture of the ooecium leads into a short atrium partially divided from the rest of the ooecial cavity by a low ring-shaped ridge (pi. VII, figs. 21, 22, 28, 29) which from the inner wall passes obliquely forwards to the frontal wall. By the use of a great magnifying power its surface is seen to be provided with small projections which stand out as free irregular teeth on its distal mar- gin (pi. VII, fig. 28). Harxier ') has pointed out a similar atrium in the ooecia of
■) 12 a, p. 170, pi. XII, fig. 10.
16
Crisia, and in Cr. ramosa Harmer he has found it partially separated from the rest of the cavity by a calcareous valve which however is not developed on the frontal wall. I have found a similar valve in Cr. hamifera^) n. sp., but in Cr. ebiirnea, (pi. VII, figs. 11, 12) Cr. denticiilaia and Cr. aculeata it is replaced by a similar continuous ring as that found in the ooecia of Meliceritites. It is provided with more or less finely ramose processes the character of which is distinctly diilerent in the three species.
The Regeneration.
Besides the regeneration of the polypide which is no doubt a common feature in all Brijozoa a regeneration of the whole individual has been shown to lake place"') in a number of species both in the Ctenostomata and the Cheilostomata, and such a regeneration I have also found in most species of the present division. While in the Ctenostomata this regeneration takes place in that manner that the old indi- vidual drops olT. and a new one takes its place, in all species the zooecium of which is more or less calcified the new individual develops within the old zooecium, and that such a complete regeneration has taken place is evident from the fact that a new aperture is seen within the old one. In the Cheilostomata I have shown that this regeneration takes place in such a manner that the different forms of bryozoids may replace each other, and the same case I have found also in the Meli- ceriliticlae. The regeneration in this division has hitherto been overlooked or inter" preted as a certain form of closure, f. insl. by Gregory who in Mel. durobrivensis speaks about a closure by means of an inverted funnel-shaped cap pierced by a pore. Here we have to do with a regeneration of a new heterozooecium within an old zooecium. As I am later to give information of the regeneration in the single species described I shall here only give a short summary of the main features of this process.
In the Melicerititidae as in the Cheilostomata we can discern between the fol- lowing four forms: ') the regeneration of a new zooecium within an old one (pi. Ill, figs. 2, 7; pi. IV, figs. 4, 8, 11,14; pi. V, figs. 2, 4, 19; pi. I, figs. 3, 4, 16); -) the regeneration of a new zooecium within a heterozooecium (pi. II, figs. 5, 7, 12; pi. V, fig. 14); ") the regeneration of a new heterozooecium within an old one (pi. I, fig. 4; pi. II, figs. 6, 9, 20, 22; pi. Ill, figs. 6, 7; pi. V, fig. 15) and ') the regeneration of a new heterozooecium within an old zooecium, which is perhaps the most com- mon form of regeneration (pi. I, figs. 18, 19; pi. Ill, figs. 1, 3, 4, 5, 27; pi. IV, figs. 3, 7, 10, 14). When a new large heterozooecium is regenerated within an old one it may fill the old aperture completely (pi. II, figs. 20, 22) or only a part of it, and in the latter case the space between the two apertures is gradually filled by a clo-
') This species whicli is talcen at lat. 33^ i) N., long. 129° 18 W. is in the dorsal surface provided with a number of hook shaped appendages eacli of wliich through a corneous joint is fixed to the proximal part of an iuternode. -) 17.
17
sure-plate. As a rule this closure begins with the formation of three slender pro- cesses (pi. II, fig. 9) starting one from the end of the new aperture and the two others from the lateral margins of the old one. They unite about half the way between the end of the new and that of the old aperture, and the three open spaces are later filled, each by a calcareous lamina. A similar closure also takes place when a new zooecium is regenerated within a large heterozoaecium (pi. II, fig. 5). In the Cyclostomata a complete regeneration seems to be very rare, and I have hitherto only been able to find a few indistinct cases in Entalophora madreporacea and Homera lichenoides.
The Closure.
The closure of old zooecia by means of a calcareous film is a well-known fact both in the Cheilostomata and the Cyclostomata, and it seems to be more common in the latter than in the former division. The real operculum of the Melicerititidce, which has been correctly interpreted by d'Orbigny has by all later authors been regarded as a closure-plate, and with the exception of Waters who mentions a peculiar form of closure in Meliceritites Royana no author seems to have noticed a real closure in this division. I have found a closure in almost all the species examined, not only in the zooecia, but also in the heterozooecia, and as a rule the zooecia are closed by a concave or sometimes flat calcareous film (pi. I, figs. 4, 14, 1(5; pi. II, fig. 7; pi. Ill, figs. 7, 26; pi. IV, figs. 6, 7, 15; pi. V, figs. 2, 19; pi. VI, figs. 4, 10), which in the species provided with an oral ledge either starts from the inner margin of the latter or at a somewhat deeper level; and in that case the aperture is lastly closed in its proximal and middle part (pi. II, fig. 7; pi. Ill, fig 25). In the other species the closure starts from the margin of the aperture and gradually extends towards the centre (pi. IV, fig. 15). In Mel. magnifica (pi. I, fig. 7) and Mel. plana d'Orb. (pi. V, fig. 12) the closure takes place by means of 3 — 5 pro- cesses starting from the margin of the aperture and later coalescing into a cover perforated by 3 — 5 holes, which are gradually closed. A third form of closure I have found in Mel. palpehrosa (pi. VII, fig. 1, 4 — 9). In opposition to what is found in the operculum the closure-plate never presents a flabelliform striation.
The Colonies.
In opposition to the rich diversity of colonial forms or forms of growth shown by the Cyclostomata the number of colonial forms presented by the Melicerititidae is very small, and we can only discern between incrustihg disciform colonies, one-or two-layered laminose fronds, and ramose colonies with cylindrical branches. The laminose colonies sometimes form hollow expansions f. inst. in Mel. Vieilbanci or a reticulate network, f. inst. in Retelea pulchella d'Orb. In many species the colo-
U. K I) Viilensk.Selsk.SUr., 7. Rickke, naluivideiisk. og iiKitheni. Alii X. 1. 3
18
nies of which are incrusting or freely ramose there appears in tlie course of time new layers of zooecia over the old ones, and the old colonies therefore get many- layered.
According to d'Orbigny the formation of new layers takes place in three diffe- rent manners. In the ramose colonies f. inst. in Mnltelea magnifica they are said to start from the proximal part of the colony whence they gradually and regu- larly extend distally. In the disciform colonies each layer may either f. inst. in Semimultelea cupula and Sem. gradata be formed by a single subcolony starting from the centre and extending towards the margin or f. inst. in Reptomultelea tuberosa and Clausimultelea tuherosa or the surface of the colonic may at the same time present a greater or smaller number of small disciform sub-colonies which at last must come in contact or fuse together. I have examined a large number of fragments of Mel. magnifica, and I have come to the result that the superficial layers are not formed in such a regular manner as d'Orbigny means, the frag- ments examined presenting in different parts of the surface a number of indepen- dent layers or patches of zooecia. PI. VII, fig. 16, shows a fragment of a colony the one surface of which presents three different layers or sub-colonies. One sur- rounds the proximal part of the rudiment while another arising from the space between the two branches extends both upwards and downwards, and a third, a small round patch is seen to the link side between the two larger ones. The op- posite surface of the fragment presented still two others. While I have not been able to find the ancestrulae of the new layers in Mel. magnifica I have seen a number of them in small fragments of Mel. tuberculata d'Orb. (pi. VI, fig. 3) and Mel. Filiozati n. sp. (pi. VI, fig. 7). As can also be seen in the figure of a young sub-colonie of Semimullelea gradata given by d'Orbigny such an ancestrula is only represented by the aperture, the rest of the zooecium being covered by the new zooecia which have arisen from it. But while this aperture in d'Orbigny's figure is seen in the centre of a small distinct sub-colony the margin of which is formed by undeveloped zooecia, the named fragments each presents a uniform con- tinuous surface formed by zooecia and heterozooecia among which are seen a number of ancestrular apertures, some of which may often be placed so near to each other that two such apertures are only divided by the breadth of a zooecium. Each aperture which is obliquely ascending is placed in the centre of a small deepening, and the zooecia and heterozooecia surrounding two or more such aper- tures placed near to each other, may be more or less irregularly arranged, but I have never seen such an aperture making the centre of a distinct sub-colony, and the zooecia arising from the ditTerent ancestrulae seem to have accommodated them- selves pretty well to each other during their growth. A fragment of this species 5 ™™ long and 3 ™™ broad presents 8 such ancestrular apertures, and another of a similar size 6. A single time I have seen a short cylindrical zooecium placed verti- cally between four zooecia and a kenozooecium, and it must no doubt be regarded as an ancestrula destined to take part in the formation of a new superficial layer.
19
Affinities.
As to the affinities of the present division there can be no doubt that the Meli- cerititidae are Cyclostomata, and in the first place tliis is distinctly shown by the form and development of the zooecia, these being long slender tubes each of which arises from the proximal part of another zooecium. The presence of numerous fine pores is also a cyclostomatous character, and rhombic or hexagonal zooecial areas divided by prominent marginal ridges may also be found in a number of Cyclostomata. The gonozooecia are provided with similar ooecial expansions as are found in the Cyclo- stomata, and the superficial layers of growth above spoken of are also found in a number of cyclostomatous species, but never in the Cheilostomata. The only two characters which might speak in favour of Cheilostomatous affinities are the pre- sence of an operculum and of heterozooecia. Apart from the fact that the latter as the common zooecia are long slender tubes they differ from the cheilostomatous heterozooecia in possessing calcareous mandibles and in lacking a membranous suboral area. The opercula are also calcareous while the opercula in the great majority of the Cheilostomata are chitinous, a calcareous operculum being only present in a few clieilostomatous species. Therefore we must regard the presence of opercula and of heterozooecia as a case of parallel development.
We here propose to divide the Ordre Cyclostomata in two subordres, the Cyclo- stomata inoperculata and the Cyclostomata operculata, and the latter may be defined in the following manner.
Cyclostomata opeiTulata.
Cyclostomata the zooecial tubes of which are much widened distally appearing on the surface of the colony as hexagonal, rhombic or qvadrangular mostly con- cave areas, in most cases divided from each other by a meshwork of ridges, in the knots of which are very often seen more or less developed tubercles. The sub- terminal aperture which has a straight or almost straight proximal margin is pro- vided with a convex calcareous operculum showing more or less distinct radiating striae. In most species are found heterozooecia the aperture of which is very often of a similar form as that found in the cheilostomatous avicularia. They always lack a membranous subopercular area and are provided with a calcareous mandible.
Family Melicerititidae Pergens. Eleidae d'Orbigny.
The family Melicerititidae has been divided by d'Orbigny in 11 and by Gre- gory in 10 genera, and the generiijue characters have been taken partly from the form and mode of growth of the colony partly from the presence or absence of heterozooecia (avicularia). As to my opinion none of these characters are sufficient to serve as base for a generic division, and I have not yet been able to distinguish
3*
20
between well divided groups based on structural diversities I prefer at present to aclcnowledge only a single genus, Meliceritites. The most significant structural di- versity is to my opinion the presence or absence of an oral ledge, but when the state of conservation is not a good one il is not easy to see whether the aperture is provided with a feebly developed oral ledge or not. Also the diversities found in the heterozooecia may perhaps be of systematic significance, but to decide these different questions it should be necessary to possess a large and well-conserved material.
Meliceritites inagnifica d'Orbigny.
Multelea magnifica d'Orbigny, Bryoz. cret, p. 649, pi. 740, ligs. 1— 9.
Melicertites magnifica Pergens, Revision d. Bryoz. p. 397.
Melicertitcs royana Waters, Annals Nat. Hist. [G] VIll 1891, p..')!, pi. VI, figs. 2, 4-6, 11.
Multelea magnifica Gregory, Cret. Bryoz. p. 316.
(pi 1, figs. 3-10, pi. VII, figs. 13- 19.)
The Zooecia which are divided by distinct marginal ridges are small and have when freely developed a more or less regular rhombic outline, but in most cases each zooecium is enclosed between two lieterozooecia which greatly influence both the size and the form of the subopercular area, and in the zooecia enclosed between the proximal halves of two heterozooecia a large part of this area is covered by the distal part of a proximal heterozooecium. No distinct tubercles. The aperture which takes up the whole breadth of the zooecium in the distal part may be con- tained two or rarely three times in the lengtli of the zooecium, but in most cases it is longer than the subopercular area. It is longer than broad, half-elliptical or roundedly triangular and surrounded by a raised peristome, sometimes provided with a small distal projection. The anter of the aperture is provided with a distinct but rather narrow oral ledge, and the convex operculum which sometimes shows a distinct flabelliform striation presents a more or less distinct triangular depres- sion which from the proximal margin extends more or less far dislally.
The Heterozooecia which are much larger than the zooecia are of a lengthened rhombic or hexagonally rhombic form with the four lateral margin more or less incurved. The opercular area which ends in a rounded apex may be very much protuding and obliquely ascending, and the inner aperture is concealed by a much concave covering (the » lateral processes*) the proximal half of which is provided with a narrow mediane fissure and the proximal margin of which by a similar transverse fissure is divided from the more or less protuding somewhat thickened distal margin of the concave subopercular area. The heterozooecia in this species are much more numerous than in any other hitherto described.
The Closure takes place in different ways. In many zooecia the aperture is closed by a concave lamina but in others (figs. 6, 7) I have seen a closure-plate of a similar appearence as the concave covering found in the opercular area of the heterozooecia, namely presenting two narrow fissures forming right angles with each other. Perhaps the latter form of closure is only the beginning of the concave
21
lamina. A second form of closure is that pointed out by Waters. It starts by the growing forth from the margin of the aperture of 2 — 5 processes which later coa- lesce after which the smaller ai)ertures between the processes are gradually filled out. Both forms of closure may be found in the same colony, but as a rule one of them is predominant.
The heterozooecia are closed by a filling out of the two fissures found in the opercular cover. —
The Ooecia are of very different form and size. Kenozooecia have not been found.
Regeneration is found both of the zooecia and of the heterozooecia, but with the exception of a few indistinct cases always in that manner that old zooecia have been regenerated by new zooecia and old heterozooecia by new heterozooecia. There has be seen as many as three regenerations in a single zooecium or heterozooecium. The Colonies are erect with cylindrical branches, and when old are surrounded by a number of superficial layers of new zooecia, which may arise in very different parts of the branches. The zooecia and heterozooecia show a disposition to arrange themselves in transvers series in such a manner that two series of zooecia are fol- lowed by a single series of heterozooecia, and in the most regular colonies these series form more or less complete, more or less unmixed, ringshaped bells sur- rounding the branches. Sometimes, however, the arrangement of the zooecia and heterozooecia may be more or less irregular, and the heterozooecia may sometimes be present in sparse numbers, irregularly distributed among the zooecia (var. royana Wat.). The zooecia placed between the distal halves of the heterozooecia are pro- vided with a small narrow subopercular area, while in the other series of zooecia the subopercular area is as a rule much broader, but the proximal part of it is concealed by the distal end of the proximal heterozooecia.
Critical remarks. In d'Orbigny's figure 2 is seen distally to each transverse series of heterozooecia a transverse series of zooecia which differ from those placed pro- ximally to the heterozooecia by the possession of a very small half-elliptical aper- ture. The zooecia of this series, however, do not differ from the other in the form of the aperture, and d'Orbigny's error musl no doubt be explained in that way that he has seen in such a series a number of regenerated zooecia (see pi. 1, fig. 3), the structure of which he has misunderstood. For the rest d'Orbigny regards the heterozooecia as »cellules ordinaires« and the zooecia as »cellules accessoires«. — In longitudinal sections of many-layered colonies of this species Waters means to have seen that the zooecia of the external layers arise from a plate covering the aperture of the subjacent zooecia. I do not agree with Waters in that question, and to my opinion a longitudinal section of such a colony only shows that the inner wall of the external zooecia has quite coalesced with the frontal wall of the subjacent ones. That the operculum or the closing plate of an old zooecium should be able to give rise to a new zooecium is not very probable, and that each zooecium of the external layer should grow forth from a subjacent one does not correspond
22
with the fact that the surface of such a colony shows a number of smaller or lar- ger patches or layers in which the single zooecia are arranged round a centre, hi transverse sections of colonies of the same species Waters has further seen sa con- traction formed by a curved plate* placed »on each side just below the opening*. I have never been able to find the two curved projections figured by Waters but sometimes two -slender conical processes w^hich arise from a transverse section of the above covering found in the opercular area of the heterozooecia. — Of this spe- cies I have examined a large number of specimens from Villedieu (Coniacian).
Meliceritites Irifolium n sp.
? Multelea semiluna d'Orbigny, Bryoz. cret. p. 646, pi. 739, figs. 8— 11. (PI. 1, figs. 17-19.)
The Zooecia wich are divided by distinct marginal ridges are small, rhombic or hexagonal, not so much longer than broad, and their distal part is as a rule not entirely taken up by the aperture. There may be found more or less distinct tu- bercles. The surface wich may be concave, flat or even a little convex is more or less distinctly ascending toward the half-elliptical aperture the length of which may be contained two or two and a half times in the length of the zooecium. The aperture is provided with a distinct but rather narrow oral ledge and a distinct peristomial thickening, and the operculum is much convex and provided with distinct radiating striae.
The Heterozooecia which may be found in very different numbers are of a si- milar form and size as the zooecia; but the surface is much more concave and not ascending toward the aperture. The latter has a similar covering as that found in the heterozooecia of Mel. magnifica. It is provided with a narrow median fissure, and by a similar transverse fissure it is divided from the opercular area.
Ooecia have not been found.
Kenozooecia have not been found.
The Closure is effected in the zooecia by means of a concave lamina and in the heterzooecia by a filling out of the fissures.
The Regeneration. The only form of regeneration which I have seen dislincllj' in this sjiecies is the formation of new heterozooecia in old zooecia. In that case the aperture of the latter is taken up by a large arched projection, the frontal and proximal part of which is provided with a similar aperture as that found in the heterozooecia, only much smaller. In old colonies I have seen a very great number of the zooecia transformed in that manner.
The Colonies are free with cylindrical branches, and in some of them I have seen superficial layers of different extension.
In the presence of a similarly developed oral ledge, in the structure of the heterozooecia and in the form of the colony this species shows affinity to Mel. magnifica. —
I have examined a number of fragments from Bruille Ponce. (Tuionian).
23
Meliceritites angulosa d'Orbigny.
Nodelea angulosa d'Orbigny Bryoz. cret. p. 610, pi. 735, figs. 4— 5 (non G).
— ornata d'Orbigny op. cit. p. 612, pi. 736, figs. 12^16.
— transversa d'Orbigny op. cit. p. 613, pi. 736, figs. 5— 8.
— pulchella d'Orbigny op. cit. p. 613, pi. 736, figs. 1 — 4.
— ogivalis d'Orbigny op. cit. p. 624, pi. 737, figs. 8 — 10.
— semiclausa d'Orbigny op. cit. p. 619, pi. 678, fig. 7, pi. 736, fig. 16. Multinodelea tuberosa d'Orbigny op. cit. p. 615, pi. 736, figs, il -11, 13— 15. Melicertites iindata Gregory (non d'Orbigny) op. cit. p. 340, pi. XV, figs. 3, 4, pi. XVI, fig. 3.
(PI. II, figs. 4-22.)
The Zooecia whicli are divided from each otlier by more or less developed marginal ridges are in most cases of a more or less distinct hexagonal form, and the semielliptical aperture is always provided with a distinct, but more or less de- veloped oral ledge, and with a distinct peristomial thickening. It takes up in most cases the whole breadth ot the zooecium in the distal part; but while in some cases it is longere than the subopercular area in others it is shorter, and sometimes its length may be contained twice in the length of the latter. More or less developed tubercles. The operculum is convex and provided with radiating striae.
The Heterozooecia which are present in very sparse number and are very vari- able in form and size are dispersed singly or in pairs among the zooecia which they always surpass in length. Most of them have about the double length of the zooecia, but sometimes they are only a little longer. In opposition to the hetero- zooecia of Mel. magnified and Mel. trifoliiim the inner aperture is always visible, not being concealed by »lateral processes*, but the form of the opercular area is subject to a very great variation, being dependent not only on the different relation be- tween its length and its (largest) breadth, but also on the form of the lateral mar- gins, and lastly on the manner in which the latter run together to form the distal end of the area. The relation named varies between 4:3 and 5:2, and the lateral margins may sometimes in the greater part of their length be parallel or allmost so, sometimes more or less convergent and sometimes more or less incurved. As to the last named ditference the lateral margins run together to form an almost semicircular curve while in other cases they make an almost rectangular bend in ordre to form the feebly curved distal end. Also the relative length of the oper- cular and the subopercular area is subject to variation, and the former may some- times be three times as long as the latter while in other cases it is only a little longer. In most cases it attains the double length. In a number of heterozooecia I have found an arched calcareous mandible which sometimes shows a similar striation as that found in the operculum.
Kenozooecia have not been found.
The Ooecia are of different form and size.
The Closure of the zooecia is effected by a concave lamina starting from the free edge of Ihc oral ledge and developing in such a way that at a certain point
24
of time the closure-plate is perforated by a fissure-like opening seated in its prox- imal and median part (fig. 7).
The Regeneration. In a few cases I have found zooecia regenerated in old ones and more freqvent a regeneration of the heterozooecia, sometimes by a new hetero- ozooecium sometimes by a zooecium (figs. 5, 7). Sometimes the new heterozooecium may fill out the whole aperture of the old one (fig. 20), but if that is not the case the space between the old and the new aperture is gradually closed by a calcareous lamina which however is not formed as a unity, but as more (as a rule three) plates filling out the spaces between as many calcareous processes. Fig. 9 shows the three calcareous processes, and in fig. 5, which presents a zooecium regenerated in a heterozooecium is seen a similar case in which the spaces between the three processes have been filled out. In fig. 7 is seen a more irregular case and in the case presented in fig. 22 the filling out of the narrow space between the old and the new aperture has been prepared by the formation of short connecting processes.
The Colonies are free with cylindrical branches, and in time increase in thick- ness by the formation of superficial layers several of which may be seen at the same time in different parts of the branch.
This species is subject to a very great variation in all respects, and I have tried in vain to divide the material examined in more different forms. We may discern between the following two chief-varieties which are however very far from being sharply limited.
Var. latirostris. The subopercular area is longer than or as long as the aper- ture, longer than broad; the oral ledge is narrow, and its height in the distal part does not attain a third part of the height of the aperture. The marginal ridges are narrow and the tubercles are small. The distal half of the heterozooecial aperture is broad.
Var angustirostris. The subopercular area is shorter than the aperture broader than long. The oral ledge is broad and its height in the distal part attains the third part of the height of the aperture. The marginal ridges and the tubercles are strongly developed.
I have examined colonies from Villedieu, Fecamp, Coulure, Vendome, St. Pa- terne, Evreux and from Chatham.
Meliceritites semiluna d'Orbigny.
Nodelea semiluna d'Orbigny, Bryoz. cret. p. 611, pi. 735, figs. 9 11. — — Gregory, Cret. Bryozoa p. 307.
(PI. VI, figs. 4- 6.)
The Zooecia which have a more or less distinct rhombic or hexagonal outline and the subopercular area of which is as a rule convex or flat, and more or less distinctly ascending towards the aperture are rarely divided by indistinct marginal ridges, and as a rule there are no tubercles. The aperture which is about as long
25
as the subopercular area and takes up the whole breadth of the zooeciuin in its distal part is provided with a strongly developed, as a rule angularly bent oral ledge, the height of which in its distal part may be contained about three times in the height of the whole aperture. The form of the latter varies between half-elliptical and roundedly triangular, the lateral margins being in their proximal half sometimes almost parallel sometimes more or less converging distally. The peristomial thick- ening is rarely distinctly developed being in most cases coalesced with the convex subopercular areas of the adjacent zooecia, and the apertures of the zooecia in the same transverse series are in most cases divided by columnar projections formed wholly or partly by the lateral parts of the peristomial thickening. The proximal part of the peristome forms a more or less prominent lip. The operculum is very convex, but in such a manner that its proximal half is provided with a triangular flat, obliquely ascending area from the margins of which the surrrounding parts are gradually descending. It is provided with distinct radiating striae.
The Heferozooecia which are about half as long as the zooecia are spar- ingly spread over the surface of the colony, singly or in pairs, the two hetero- zooecia belonging to a pair being either placed side by side or divided from each other by a single zooecium. The strongly projecting obliquely ascending aperture is as long as broad or a little longer and has a somewhat variable form, the two lateral margins being more or less converging distally. No »lateral processes*.
Ooecia have been found.
No Kenozooecia.
The Closure takes place by means of a concave or in most cases flat lamina which arises a little within the free edge of the oral ledge from which, therefore, il is distinctly defined. A similar closure I have seen also in a hcterozooecium.
The Regeneration. I have seen cases of regeneration both of zooecia and of heterozooecia.
The Colonies are free, with cylindrical branches, and in some of the fragments examined I have found superficial layers.
Mel. semiluna is nearly related to Mel. angulosa and may perhaps be regarded as a constant variety of this species, from which it is most easily discerned by the lack of or the feeble development of the marginal ridges and the tubercles, the form of the operculum and the mode of closure. I have seen a number of fragments from Bruille-Ponce (Turonian).
Meliceritites palpehrosa nov. nom.
Melicertites semiluna d'Orbigny, Bryoz. cret. p. 623, pi. 736, fig. 20 — 21. noil — — Gregory, Cretac-Bryoz. p. 343.
(PI. Vll, figs. 1—9.)
The Zooecia are chiefly represented by their large half-elliptical apertures which as a rule take up most of the surface of the colony. Marginal ridges and tubercles
D K. I). Vidensk. Selsk. Skr., 7. Kiukke, ti,Tturvideiisk. oti matheiii. Afci. \ I. 4
26
are not developed. The aperture is provided with a very distinct, but rather nar- row oral ledge, but a peristomial thickening is very seldom distinct, being in most cases coalesced with the surface of the small, triangular mostly convex *suboper- cular area the height of which in most cases is contained about two times in tlie height of the aperture. The apertures placed in the same transverse series are in most cases divided from each other by columnar projections wholly or partly formed by the lateral parts of the peristomes. The operculum is convex witli di- stinct radiating striae.
No Heterozooecia.
No Kenozooecia.
Ooecia have not been found.
The Closure as a rule takes place in a very singular manner. It starts by an enlargement of the oral ledge, and at the same time the distal and the proximal margins of the latter get connected by a number of vertical columnar projections divided by rounded pits. As this distal closure-plate gradually increases in size and in thickness the pits increase in length, at the same time diminishing in breadth, and the oral ledge thus gets transformed into a strongly arched structure very much like a cheilostomatous ooecium or an eye-lid. According to their age these distal closure-plates are either smooth or their surface presents a series of more or less distinct impressions, the vestiges of the original pits. Somewhat later than the distal also a proximal closing plate begins to develop, starting from the proximal margin of the aperture. In opposition to the distal plate the latter is as a rule concave or flat, and sometimes directed obliquely inwards. By and by the originally large aperture is transformed into a narrow fissure-like opening which is lastly filled out. This process of closure, however, shows a great variation even in the same fragment, the two plates being developed in very different degree, and in some cases the distal one may be very small (figs. 1, 9). In a few zooecia I have found the closure effected in the usual way by means of a concave or flat lamina (fig. 2).
Regeneration has not been found.
The Colonies are free with cylindrical branches, and I have seen no superficial layers.
I have seen rather numerous specimens of this species from Villedieu.
Meliceritites Lorieri d'Orbigny.
Vincularia Lorieri d'Orbigny, Bryoz. Cret. p. Gl, pi. (501, figs. 18 — 20.
Melicertites semiclausa Pergens, Revision d. Bryoz. p. 394. non Melicertites semiluna d'Orbigny, Bryoz. Cret., p. 623, pi. 736, figs. 20 — 21. non Melicertites semiclausa Gregory, Cretac. Brj'ozoa, p. 328, pi. XIV, figs. 1—3.
(PI. IV, fig. 18.)
The Zooecia which are at the utmost as long as broad and in most cases a little broader than long are not divided by distinct marginal ridges, and the peri-
27
stomial thickenings are either quite confluent with the suboral areas of the adja- cent zooecia or indistinctly divided from the latter. Sometimes there may be found indistinctly defined tubercles between the zooecia of the same transverse series. The aperture which is broader than high has a broadly rounded anter and a well- developed sharply defined oral ledge which only decreases very little in heigth to- wards the proximal margin. A very much convex operculum has only been found in a small number of zooecia. The triangular flat suboral area is obliquely de- scending towards the aperture.
The Heterozooecia are very rare, and in each of the four fragments examined which have a length of 12 — 20 '"™ they have only been found in a number of 1 — 4. They are more than twice as long as the zooecia and are of a similar form as the heterozooecia figured in pi. II, fig. 19 and belonging to Mel. angulosa. The two lateral margins, however, are much more incurved, and the aperture therefore is al- most completely hour-glass-shaped, the two dilatations being about of the same form and size and being connected by a very narrow median part, the breadth of which is contained about four times in the breadth of the proximal margin. The suboral area has the same form and size as in the zooecia. Each heterozooecium is bor- dered by two pairs of zooecia, and those belonging to the distal pair has a similar, but still more oblique position as in those seen in pi. 11, fig. 18.
Ooecia have not been found.
No Kenozooecia.
The Closure takes place in great measure by the aid of a flat or somewhat concave lamina placed at the rule at a much deeper level than the oral ledge.
A Regeneration has not been found.
The Colonies. I have examined four incomposite cylindrical fragments each provided with 1—2 lateral branches. The zooecia, tlie apertures of which are gene- rally placed very near to each other, are arranged in distinct transverse series, each containing about 20 zooecia.
Le Mans (Cenomanian).
In the specimens examined a number both of the closure-plates and of the opercula have undergone a more or less complete decalcification, and several of these structures are represented only by thin chitinlike membranes, which are left unaltered after a fragment has been dissolved in muriatic acid.
Melicerititcs Caniii n. sp.
[P\. Ill, figs. 20-27.)
The Zooecia which are divided by distinct marginal ridges, are more or less regular hexagonal, twice as long as broad, and the large about half-elliptical aper- ture which only in its distal half takes up the whole breadth of the zooecium is a little shorter than the concave or mostly saddle-shaped subopercular area which is strongly ascending towards the well-developed peristome. The aperture is provided
28
with a distinct, but narrow perlstomial thickening, and with a well-developed oral ledge the height of which in its distal part may be contained four or five times in the height of the whole aperture. The operculum is convex and provided with very fine radiating striae. No distinct tubercles.
The Heterozooecia have about the same form and size as the zooecia being only a little narrower, and the chief dilTerence between them and the zooecia is that they are provided with a very small aperture which is either of a somewhat si- milar form or more elongate. They are provided with a well-developed oral ledge and with a more or less distinct peristomial thickening, but their height is some- what variable and may be contained four or five times in the height of the whole heterozooecium. The operculum has a similar structure as that found in the zooecia.
The Kenozooecia. A somewhat variable number of kenozooecia of the same form and size as the heterozooecia are mixed with the heterozooecia, and these two forms of zooids take up about the one half of the surface in larger or smaller portions of the fragments examined.
Ooecia have not been found.
The Closure. I have seen a few zooecia closed by a concave lamina, and a larger number of wholly or partiallj' closed heterozooecia. The closure starts from the edge of the oral ledge, and proceeds in tliat way that the last part of the aper- ture which is closed is a small median opening distally to the proximal margin.
The Regeneration. I have seen a few zooecia regenerated in old ones.
The Colonies are free, but I have only seen a number of small (long 4"'"') unbranched cylindrical pieces, each of which contains c. 10 longitudinal series of bryozoids.
Fecamp (Middle Senonian).
Meliceritites gracilis Goldfuss.
Ceriopora gracilis Goldfuss, Petref. Germ., vol. 1, p. 3,'i, pi. X, figs. 11a — c. non Meliceritites gracilis Roemer, Vcrstein. nordd. Kreideg., p. 18, pi. V, fig. 13. noil — — Caiiu, Bull. Soc. Gcol. de France, 3e serie, t. XXV. 1897, p. 752, pi. XXll, figs. 1-2.
Meliceritites gracilis Gregory, Cret. Bryoz., vol. 1, p. 324, figs. 38a— b.
(figs, a, b.)
The Zooecia which are divided by more or less distinct marginal ridges are as a rule rhombical or hexagonally rhombical, and the triangular aperture which lakes up the wliole breadth in the distal part of the zooecium and rarely attains the half length of the latter is a little longer than broad and provided with a well- developed oral ledge. There is a well-developed peristomial thickening the poster of which forms a prominent lower lip which is often left as a transverse bridge after the rest of the frontal wall has disappeared. The frontal wall is distinctly concave. An operculum lias only been found in a single zooecium,
29
Heterozooecia and Ooecia have not been found.
The Kenozooecia. Only a suigle time two small kenozooecia have been found in an angle between two branches.
The Closure which has been found in many zooecia is effected by means of a flat or concave calcareous plate which as a rule starts from the free edge
1. of the oral ledge and therefore fuses together ci.
with the latter. Sometimes, however, it starts at ' <w|||r; Js-,
a deeper level, and in that case the marginal ,^j^ ^jr ^.|
depression is distinctly divided from the closure- ,..^.r^ '^
plate. ^T
The Colonies are freely branched with cy- lindrical branches, in which the zooecia are ar- ranged in more or less regular, alternating trans- , , '^' '' , ° . o ' o ^1 closure-plate.
verse series each of which in the primary or
incomposite colony contains 14 — 16 zooecia. Gradually the colonies fig. a. get multi-layered, and in one of the original specimens of Goldfuss
1. oral ledge. there is found four different layers the outmost of which presents
o. operculum. ^ number of different centra, k. kenozooeciura. . . , , j, i i i ■ i
1 ins species is as a rule badly preserved, and most zooecia liave
either lost the larger part of their frontal wall or this has been in dilTerent degree covered by incrustations. These circumstances together with the frequent closure of tlie zooecia are the causes whj' only very few apertures present the characteri- stical oral ledge the length of which attains more than the third part of the length of the whole aperture.
Of this species I have been able to investigate not only the original specimens of Goldfuss kept in the palseontological museum of Bonn (Prof. G. Steinmann), but also a number of exemplars from the palseontological museum of Miinster (Prof. H. Wegner), which have been found in a conglomerate of gypsum at Essen. Under the name of Ceriopora gracilis Goldf the latter were mixed with a number of species belonging to different families and genera, and among these I found be- sides another species of Meliceritites a species of Enialophora to which I must refer the figure which accompanies Roemer's description of Mel. gracilis. While the aper- ture of the latter species is longer than broad, and the zooecia are as a rule about twice as long as broad the aperture in Roemer's figure is broader than long and the zooecia only half a time longer than broad. The description, however, corre- sponds better to the original specimens than to the figure. I provisionally i)ropose the name Enialophora Roemcri for this species of which I here give the following description. The hexagonal zooecia which are only half as long as broad are provided with a very concave frontal area and divided by strongly developed marginal ridges. The aperture which takes up the larger part of the breadth in the distal part of the zooecium, and together with the peristome about half the length of the whole zooecium is triangularly rounded, broader than high and pro-
30
vided with a strongly developed peristomial thickening, the proximal part of which forms an obliquely or even vertically ascending under lip. The fragments examined are elongate clavate, rounded or a little compressed and accreasing gradually in thickness towards the tip which is about double as thick as the proximal end. The fragment to which the zooecia belong, which are figured in PI. VII (figs. 25— 26), has a length of 10 ™'" and the thickness of the tip is 4 """.
I think that the two specimens figured by Gregory both must be referred to Mel. gracilis Goldf., but in that case they are figured in the inverted position, and the supposed aperture in Gregory's figures seems to be identical with the opening seen in the proximal part of my figure b and which is due to a partial destruction of the frontal wall.
Meliceritites gothica nov. nom.
Mclicertites gracilis Marsson (non Goldfussj, Bryoz. Kiigen p, 46, pi. IV, fig. 8.
(PI. I, figs. 11—14).
The Zooecia which are divided by distinct, more or less developed marginal ridges, are hexagonallj' rhombic, and the very concave suboral area is strongly, sometimes allmost vertically ascending towards the aperture which does not take up the whole breadth in the distal part of the zooecium. The tubercles are distinct but developed in very difTerent degree. The aperture which is provided with a distinct peristomial thickening and a distinct, but rather narrow oral ledge has the form of a gothic arch, the lateral margins in their distal part running together to form a more or less distinctly angulate terminal portion while in their proximal part they are somewhat converging proximally or parallel. The supraoral tubercle forms a more or less developed beak-shaped projection. The convex operculum is provided with a distinct llabelliform striation, and, besides, with a number of small claviform projections, which are arranged in a similar manner and seem to be perforated.
The Heterozooecia are as a rule found in groups of 2 — 7, rarely singly, and they larger groups are generally mixed with a number of kenozooecia. They are as long as or somewhat longer than the zooecia and provided with a narrow, more or less projecting aperture of very different length the lateral mar- gins of which are almost parallel or very little converging distally. The fissure- like opening which has a proximal triangular enlargement is bordered bj' two obliquely descending lateral thickenings.
Ooecia have not been found.
The Kenozooecia which are of the same form and size as the zooecia are found singly or in groups and as a rule together with heterozooecia.
The Closure is effected by means of a flat or concave lamina (fig. 14).
The Regeneration. There has been found both a regeneration of new zooecia in old ones, of new heterozooecia in old zooecia and rarely of new heterozooecia in old ones.
31
The Colonies are incomposite, and the cylindrical fragments examined contain c. 10 zooecia in each transverse series.
I have examined a rather scarce number of fragments from Riigen and from Moen, and while in the specimen from Riigen the aperture is only as long as the suboral area in those from Moen it is more than half a time longer.
Melicerilitis gothica, var. acuminata n.
(PI. II, figs. 23—24.)
The Zooecia are hexagonal, and the aperture which is not far from being double as long as broad has the form of an elongate triangle the lateral margins of which are somewhat convex in their proximal part and a little incurved in their distal half. The distal part of the oral ledge is strongly developed, and may sometimes be allmost half as long as the whole aperture. All other features as in the main form.
Very common in the chalk (upper Senonian) from Tullslorp (Sweden) and from Svinkloven (Jutland).
McliceiMtites pentagontim n. sp.
(PI. IV, fig. 22.)
The Zooecia which are divided from each other by well-developed marginal ridges are more or less distinctly hexagonal, and in most cases about half a time as long as broad. As a rule distinct tubercles. The large aperture which does not take up the whole breadth of the zooccium in its distal part is more or less distinctly pentagonal, the two distal sides of the- pentagone being sometimes repre- sented by a curve while the two proximal paired sides are always distinctly con- verging proximally. It is provided with a well-developed oral ledge the two halves of which form with each other an acute or sometimes right angle. The oral ledge which is very narrow within the two paired proximal sides does not as in other species attain its largest height in the middle line, but in the two lateral halves. There is a well-developed peristomial thickening, the distal strongly projecting part of which belongs to the marginal ridges, and this part together with the supra- oral tubercle often forms a more or less prominent beak-like projection. All the hitherto examined specimens have lost their opercula.
The Heterozooecia, which are spread among the zooecia in groups of 2 — 9 are of somewhat variable size, the smallest of them, however, not being much smaller than the zooecia. They are provided with a long narrow proximally gradually widening aperture, the narrow opening of which is bordered by two lateral pro- cesses. The aperture is of very different length and in the largest of them it is longer than the concave suboral area and takes up the whole breadth of the hetero- zooecium in its distal third part.
32
Ooecia have not been found.
Kenozooecia of the same form and size as the zooecia are often found together with the heterozooecia in a number of 1—3.
The Closure takes place by means of a concave lamina.
The Regeneration. Besides a regeneration of new zooecia in old ones there is found very commonly a regeneration of heterozooecia in zooecia.
The Colonies are incomposite, and the examined cylindrical fragments contain 10 — 12 zooecia in each transverse series.
Numerous specimens from the chalk (upper Senonian) of Tullslorp (Sweden).
Melicerilites Roemeri v. Hagenow.
Ceriopora Roemeri v. Hagenow, Monogr. d. Rugensclicn Kreidc-Verst. (N. Jahrb. 1. Mineral 1839, p.
285, pi. V, figs. 7a— b. Melieeritites (Ceriopora) Roemeri Roemer, Verst. nordd. Kreidegeb. 1841, p. 18.
Vaginopora Roemeri v. Hagenow, Geinitz Grundr. d. Versteinerungskunde, 1846, p. (i02, pi. XXlllb. fig. 20. non Ceriopora velata v. Hagenow, Monog. Riig. Kreide-Verst. (N. .lalirb. f. Mineral.) p. 285, pi. V, fig. (i.
Nodelea propiuqva Marsson, Bryozoen Riigen, p. 47, pi V, fig. 1. non Melieeritites gracilis Marsson, Bryozoen Riigen, p. 46, pi. IV, fig. 8.
(pi. V, figs. 18—24.)
The Zooecia which are in most cases only half as long as broad are hexagonal and divided from each other by a meshwork of distinct ridges in the knots of which there is found more or less developed often prismatic tubercles. The half-elliptical aperture which may be a little longer than broad and does not take up the whole breadth of the zooecium in its distal part is as a rule much shorter than the concave suboral area. It is provided with a well-developed peri- slomial thickening, and in especially well preserved zooecia there is seen a distinct, but rather narrow oral ledge. All the specimens examined have lost their opercula.
The Heterozooecia. There is found two different forms of heterozooecia the larger of which is avicularia-like and provided with a long narrow aperture. They are present in very scarce number, and in most of the fragments examined there has been found only a single one, rarely two or three. They are always larger than the zooecia, and the longest of them have a length a little more than twice that of the zooecia. The aperture which is longer than the suboral area and three or four times as long as the breadth in tlieir middle part is provided with a me- dian dei)ression bordered by two narrow lateral thickenings. The other form of heterozooecia is found in large numbers among the zooecia, rarely singly, but as a rule in groups of 2 — 10, in most cases mixed with a number of kenozooecia. They have the same form and size as the zooecia from which Ihey differ in the form of the apertures which, however, is subject to great variation. The same is the case also with their size as their length may be contained five to two and a half times in the length of the zooecium. In opposition to the zooecial apertures they have a narrow, feebly developed, perislomial thickening and a broadly rounded
33
distal margin, but while the smaller of them are nearly circular apart from the straight proximal margin the larger of them are more or less ligulate with almost parallel or proximally somewhat converging lateral margins. While those hetero- zooecia that are provided with the smaller apertures like the zooecia have an an- gularly bent distal end, the distal end of the others corresponds to a smaller or larger distal part of the ligulate aperture. The larger part of the aperture is fdled by a concave lamina which no doubt corresponds to the oral ledge in the zooecial aperture, but in most cases this lamina has been expanded by a more or less ad- vanced closure, and there is only left a fissure-like or narrow triangular opening. Sometimes the whole aperture is filled, and only in a few cases there has been found a half-elliptical or semi-circular opening (fig. 19).
The Kenozooecia which have the same form and size as the zooecia are as a rule found together with a number of heterozooecia, but they are not so frequent as the latter.
The Closure is effected by means of a concave lamina but it is much more common in the heterozooecia than in the zooecia.
The Regeneration. A regeneration of new zooecia in old ones is not frequent, but in most fragments there is found a number of old zooecia the aperture of which have been filled by heterozooecia with a small aperture (fig. 19).
The Colonies are uni-layered, and the cylindrical branches bear alternate trans- verse rows of c. 15 zooecia.
I have found numerous specimens in the chalk from TuUstorp (upper Senonian) Sweden.
When Gregory refers, v. Hagenow's and Roemer's descriptions of Mel. Roemeri to Mel. gracilis Marss. he relies upon the authority of Marsson, who, however, is wrong in his supposition. In Hagenow's figure of the former species the length of the aperture is contained about thrice in the length of the zooecium, and that is just the case in most exemplars of Mel. propinqva, while in Mel. gracilis Marss. the aperture is as long as or even longer than the suboral area. But also the very short and incomplete descriptions agree with Mel. propinqva and not with Mel. gra- cilis. V. Hagenow designates the apertures as „Kreisrunden oder abgerundet drei- eckigen .... Poren", but these terms cannot in any way be used about the elongate distally somewhat pointed apertures of Mel. gracilis, and when both authors speak about zooecia in which the aperture is only represented by a fine pore, they evidently speak about the heterozooecia. Such a heterozooecium is seen in Hagenow's figure.
Meliceritites sqvaniala Marsson.
Marsson, Bryozoen Riigen p. 47, pi. IV, fig. 9. (pi. V, figs. 13-17.)
The Zooecia which at the utmost may be half a lime longer than broad are in most cases as broad as long and even a little broader. They are hexagonal and
1). K. 1). Vklensk. Si-lsk SUi-., 7 It.-eUI.e. n;iluiviili!nsU. or m.nlhem. M\\. X. 1. c-
34
divided by distinct ridges, of wliich the two distal ones may often be more or less cur- ved. The tubercles are either lacking or very feebly developed. The more or less strongly protruding, half-elliptical aperture which at the utmost takes up the half breadth in the distal part of the zooecium is a little longer than broad and about as long as the concave or saddle-shaped suboral area which rises obliquely to- wards the aperture. In well preserved zooecia there may be found a narrow oral ledge.
The operculum is radially striated, and its pores seem to be perforations of small rounded elevations.
The Helerozooecia which are present in rather scarce numbers are of very diffe. rent size, the smaller of them being onlj' as long as the zooecia while the larger may attain more than the double length of the latter. While the former have an elongate triangularly rounded aperture, the length of which is contained 3—2 times in the length of the whole heterozooecium the latter have an elongate ligulate aper- ture, which is longer than the suboral area. Dislally to the triangular opening is seen a longitudinal depression, bordered by two marginal thickenings.
Ooecia have not been found.
Kenozooecia of the same form and size as the zooecia are found in most frag- ments, generally in groups of 2 — 10.
The Closure takes place by means of a concave lamina.
The Regeneration. There is not rarely found a regeneration of new zooecia in old ones, and when the new aperture is not sharply divided from the old, its pre- sence may be inferred from that it is much smaller and much more protruding than the other. Another form of regeneration which is perhaps more frequent is that the aperture of an old zooecium is filled by a small heterozooecium, the roun- dedly triangular aperture of which is as a rule obliquely protruding, and I think that Marsson statement: „Die Zellen besitzen an der Spilze oft auch ein kleines, zuweilen von einer Pore durchbortes Warzchen" must be referred to this form of regeneration. In a few cases I have seen a zooecium regenerated in a large hetero- zooecium (fig. 14) and a new large heterozooecium in an old one (fig. 15).
The Colonies are incomposite, and the cylindrical branches have c. 10 zooecia in each transverse row.
Numerous specimens have been found in the chalk (upper Senonian) from Moen (Denmark) and from Tullstorp (Sweden).
Meliceritites Filiozati n. sp.
Clausimultelea tuberculata d'Orbigny, Hryoz. cret. p. 656, pi. 784, figs. 12—15,
(PI. VI, figs. 7—10.)
The Zooecia which are in most cases twice as long as broad and more or less regularly rhombic, are divided by well-developed marginal ridges, and the suboral area is as a rule a little convex. No tubercles. The half-elliptical aperture, the
35
length of which is very often contained twice in the length of the suboral area is provided with a distinct but rather narrow oral ledge, and together with the nar- row peristomial thickening very often takes up the whole breadth in the distal part of the zooecium. The convex operculum which has been lost in most zooecia presents a distinct flabelliform striation.
The Heterozooecia which are spread singly among the zooecia in rather scarce number are as long as or even longer than the zooecia. The aperture which in most cases is a little longer than the convex suboral area, is about half as long as broad, and the two allmost parallel lateral margin run together distally in a very broad curve. We may discern between two obliquely ascending lateral thickenings and a deep median somewhat hour-glass-shaped depression, in the proximal half of which is seen the half-elliptical inner aperture.
Ooecia have not been found.
Kenozooecia of a similar form and size as the zooecia are scattered among the latter in rather scarce numbers singly or more together.
The Closure takes place by means of a flat lamina which arises proximally to the oral ledge.
A Regeneration has not been seen.
The Colonies. I have examined a number of laminate fragments consisting of 3 — 4 layers of zooecia, and to judge from these the colony seems to have had a somewhat similar structure as that figured in d'ORBiGNv's pi. 784, fig. 12 and referred to ClausinmUelea tnbercnlata. But while in this figure the sub-colonies which compose the difTerenl layers partly appear as sharply defined small discs, I have found no such in the few fragments of the present species, which present ancestrulae, but the small sub-colonies, the ancestrulae of which are sometimes placed very near to each other in a number of 2 — 7, are fused together, partly by the aid of Kenozooecia of very ditTerent form and size. The only visible part of such an ancestrula is the obliquely ascending aperture, and as the zooecia imme- diately surrounding it have an ascending frontal wall, each ancestrular aperture is the centre of a more or less deep depression, which may be elongate when two ancestrular apertures are placed very near to each other (fig. 7). hi a single frag- ment I have found a short, cylindrical erect zooecium (fig. 8) arising between four zooecia and a kenozooecium; and I must regard it as an ancestrula destined to give rise to a new sub-colony.
A number of fragments from Fecamp (Middle Senonian).
Meliceritites tubcrculata d'Orbigny.
'.'Clausimultclea tubcrculata d'Orbigny, Bryoz. Cret. p. (j.56, pi. 7S4, figs. 12-lJ.
ipl. VI, figs. 1—3.)
The Zooecia which are divided by distinct ridges and generally present a con- vex or saddle-shaped distally obliquely ascending suboral area are of a rather
5*
36
variable form and size, but in most cases they are about twice as long as broad and sometimes much longer. No tubercles. The aperture which is provided with a distinct but rather narrow oral ledge and a narrow peristoniial thickening presents some variation in form and dimensions, but is generally half as long as broad, and the two lateral margins are somewhat converging proximally. The convex oper- culum shows a distinct flabelliform striation. —
The Heterozooecia which are spread among the zooecia singly or more together are about of the same length as the latter, and the beak-shaped more or less pro- jecting distal end is as a rule much shorter than the concave suboral area. The narrow triangular obliquely ascending aperture is provided with an almost fissure- like opening bordered by two inwardly sloping lateral thickenings. In a single case I have found a calcareous mandible (fig. 2).
Ooecia have not been found.
The Kenozooecia, which have a similar form and size as the zooecia are in large numbers spread among the zooecia.
The Closure lakes place by means of a concave lamina.
The Regeneration, hi the fragments examined I have only seen the regeneration ot a new heterozooecium from an old one (fig. 1).
The Colonies. I have examined a few laminate fragments consisting of a num- ber of layers, and in one of them the zooecia are as in the above fragments of Mel. Filiozati arranged in groups around a number of ancestrulae.
The basin of Paris (Danian), Fecamp (Middle Senonian).
When I refer the present species and not Mel. Filiozati to Clausinniltelea tuber- culata d'Orb. it is because it agrees better with the figure given by d'Orbigny, not only in the form of the apertures but also in the large number of the kenozooecia. For the rest d'Orbignv's description as also his figure bear witness to a very super- ficial examination as the zooecia according to this author, quite in opposition to what is really the case, are only represented by their apertures. Also the relation between the apertures and the kenozooecia in the figure leaves no doubt, that the latter is constructed and not made according to nature.
Meliceritites pyrenaica d'Orbigny.
Foricula pyrenaica d'Orbigny, Bryoz. Cret. p. (),')8, pi. 741, figs. 16 — 18. (PI. VI, figs. 11-L'l.l
The Zooecia which are never divided by marginal ridges are subject to a veiy great variation both in respect to the form and size of the aperture and to the form and relative extension of the suboral area which never presents distinct pores, but always a small number of more or less developed pits. The apertuie which in the best preserved zooecia shows a distinct or even well-developed oral ledge is in most cases semi-elliptical or makes a larger part of an ellipse, but it may also be semi- circular, (jvadrangularly rounded, and some times much broader than high (fig. 11).
37
The distal part which is not rarely provided with a more or less distinct beak- shaped projection (figs. 13, 14, 16) is sometimes angularly bent from side to side (figs. 13, 14), while in most cases it is broadly rounded, and within the proximal margin there is generally found a more or less distinct broad low prcjjection, the median part of wiiich is provided with an impression or indentation (figs. 12, 13, 17,21). The operculum whicli has been found only in a very small number of zooecia sliows a flabelliform striation and a number of pores. The suboral area which is always feebly developed is rarely broad and short, and in thai case il is pro- vided with a pit on each side (fig. 19). In most cases il is long and narrow and provided with 2 — 4 pits arranged in different manner, and sometimes the peristomes of the neighbouring zooecia come in contact with each other in such a manner that the suboral area is only represented by a proximal and a distal pil (fig. 12). The rich deposition of calcareous matter which lakes place in this species may go on in a very ditTerent manner, and while in some colonies the pits increase both in number and in size, and the suboral area therefore shows a rich areolation (fig. 16), in others the pits are gradually elTaced, and the suboral areas are transformed into an inter- lacing net-work of convex pillars (fig. 15).
The Heterozooecio which are present in very scarce number and not even found in all the fragments examined are as a rule a little longer than the zooecia. The more or less projecting aperture is triangularly rounded, a little longer than broad and the two lateral margins converge to form a rather broadly rounded distal curve. No lateral thickenings. The suboral area is provided with similar pits as those found in the zooecia, and there may be found a projection within tlie proximal margin (fig. 21).
Ooecia have nol been found.
No Kenozooecia.
A Closure has not been seen with certainty in any of the fragments examined.
The Regeneration. In all the specimens examined a larger or smaller number of the ajjcrtures are much more projecting than the others, and when we have to do with a larger fragment which presents the original distal end tolerably intact we find that the number of these projecting apertures increases towards the pro- ximal end, the surface of which is chiefly or exclusively composed of them. A conse- quence hereof is that the proximal end of such a fragment is much thicker than the distal, and for inst. in one from Villedieu which has a length of 13 mm., the distal end has a thickness of 1,5 mm. but the proximal end of 2,5 mm. The named |)rominent apertures are very often distinctly or even much larger than the com- mon ones and of a diflerent form (fig. 17), and their arrangement is always more or less irregular as a larger or smaller number of them have another direction than the common apertures. Sometimes we even find specimens in which these aper- tures are ])laced in all possible directions (fig. 20). 1 cannot doubt but that we have here to do with a process of regeneration which differs from that commonly found in Ihis division therein that the aperture of the new zooecium proceeds so far be-
38
yond that of the old one, and at the same lime the rich deposition of calcareous matter speedily effaces the limits between the two apertures and prevents us from deciding how many times a certain zooecium has been regenerated. In a specimen from Tours (fig. 11) the apertures are directed obliquely downwards, and some of the zooecia show a strongly developed dorsal surface provided with a number of deep pits.
Numerous specimens from Villedieu and Tours.
Meliceritites dicholoiiia (?) d'Orbigny.
Semielea dicliotoma d'Orbigny, Bryoz. Cret. p. 637, pi. 638, figs. 6— 8, pi. 738, ligs. 10 — 11.
(PI. V, figs. 1, 2.)
The Zooecia which are twice as long as broad are not divided by distinct marginal ridges, and the distally ascending suboral area is in most cases longer than the aperture which together with the well-developed pcristomial thickening takes up the whole breadth of the zooecium in its distal part. No tubercles. The aperture which is as broad as long or even broader than long is provided with a well-developed oral ledge, and the two lateral margins either run together in a broad distal curve or in a curve more or less angularly bent. The convex oper- culum shows a distinct flabelliform striation. —
The Heterozooecia which are spread among the zooecia, rarely singly, mostly in groups of 2 — 8 have the same length as the zooecia, and the somewhat projec- ting distal half is provided with a triangular aperture, about twice as long as broad. All the heterozooecia examined were closed by a somewhat concave lamina.
Ooecia have not been found.
No Kenozooecia.
The Closure takes place by means of a flat or concave lamina which in the zooecia sometimes has started from the edge of the rim, sometimes at a deeper level. —
The Regeneration. I have seen many cases of regeneration both of new zooecia in old ones, of new heterozooecia in old ones and of heterozooecia in old zooecia- 1 have examined a hollow compressed fragment from Tours lent me by Dr. Pergens.
Meliceritites armata n. sp.
Hornera SUeiistrupi Pergens (partim), Bryoz. de Faxe, p. 218, pi. XllI 2 a, 2 b.
(PI. Ill, figs. U-16 )
The Zooecia (long 0,8 mm.) which are divided by well-developed marginal rid- ges are about twice as long as broad, and the concave or saddle-shaped suboral area is obliquely ascending towards the somewhat projecting distal end. No tuberc- les. The aperture, the length of which in most zooecia is contained about Ihiee times in the length of the whole zooecium is about as broad as high and ])r<)vide(i
_ 39
with a strongly developed peristomial thickening. There is found a distinct, l3ut narrow oral ledge, and the lateral margins as a rule converge a little proxinially. The convex operculum is provided with a flabelliform striation.
The Heterozooecia, which in most fragments are found in a number of 2 — 10 either singly or two together are as a rule not spread among the zooecia, hut to- gether with the kenozooecia form a longitudinal belt which takes up about the third part of most fragments examined. They have a similar form and size as the zooecia, but are provided with a triangular distally rounded aperture, not twice as long as broad, .the length of which is contained about three times in the length of the w'hole heterozooecium. It is provided with two lateral thickenings.
The Kenozooecia which have the same form and size as the zooecia together with the heterozooecia form transverse series, each containing 3 {2 — 4) zooids.
Ooecia have not been found.
The Closure is effected by means of a concave lamina.
The Regeneration. I have seen a regeneration of new zooecia in old ones, and a corresponding regeneration of heterozooecia.
The Colonies (Diam. 0,8— 1 mm.) are incomposite, and the cylindrical fragments have their zooids arranged in regular transverse series, which, however, in most cases are more or less oblique. The zooecia which as a rule are bordered by parallel lateral margins in the larger part of their length, generally are found in a number of six in each transverse row, but in rare cases the extension of the long- itudinal belt formed by the kenozooecia and heterozooecia may be diminished by the increase of the number of zooecia in one or more transverse series, and some- times it may even be divided in more parts, one or more transverse series forming closed rings round the branch. —
Numerous specimens from Faxoe and Rejstrup (Danian), Denmark.
Mcliceritiles Steenslriipi Pergens.
Hornera Steenstrupi Pergens (partiin), Bryoz de Faxe. p. 218, pi. XIII, ligs. 3, 4.
(PI. Ill, figs. I'i, 13.)
The Zooecia (long. 0,5 mm.) which are divided by well-developed marginal ridges are in most cases more than twice as long as broad, and the suboral area is obliquely ascending towards the aperture which together with the well-developed peristomial thickening takes up allmost the whole breadth in the distal part of the zooecium. No tubercles. The half-elliptical aperture lacks a distinct oral ledge, and its length is contained about two and a half time in that of the zooecium. The not very convex operculum shows a flabelliform striation.
The Heterozooecia which are much smaller than the zooecia and generally of an elongate sexangular form are never spread among the latter but together with a few kenozooecia form a longitudinal belt, which takes up a fourth to a sixth part of the extension of the fragments examined, and in which the zooids are arran-
40
ged in more or less oblique transverse series each containing 1 — 4 zooids. As in most of the latter the marginal ridges between the single zooids have vanished as also the apertures of the heterozooecia it is not easy to make up the relative num- ber of the two forms of zooids, but the heterozooecia are at any rate much more numerous than the kenozooecia, and sometimes take up the whole belt especially when the latter is narrow. The very small aperture is allmost circular — apart from the straigth proximal corner — , and the larger part of it is filled by a con- cave lamina, the proximal part of which is perforated by a semicircular opening.
Ooecia have not been found.
The Kenozooecia which have the same form and size as the heterozooecia are spread among the latter in scarce number and seem as a rule to be placed in the middle of the longitudinal belt.
The Closure is effected by means of a concave lamina.
The Regeneration. Hitherto I have only seen a regeneration of new zooecia in old ones.
The Colonies (Diani. 0,4 — 0,8) are incomposite, and the cylindrical fragments show an arrangement of the zooecia in regular more or less oblicjue transverse series, each of which contains 6 — 11 zooecia. As a rule the apertures of the outer- most zooecia in each transverse series are distinctly larger than the other.
Numerous specimens from: Faxoe and Rejstrup (Danian), Denmark. Of the two very distinct species which have been confounded under the name Hornera Steen- striipi the present is found in Faxoe in much larger numbers than the other (M. armata), and, therefore, I think it likely that it should keep the specific name given by Pergens. According to the explanation of the plate this author refers the frag- ment figured to an old colony, no doubt because the marginal ridges between the heterozooecia and kenozooecia have been indistinct as is the case in most specimens of this species from Faxoe, while he has regarded the specimens of Mel. armata as young colonies of the same species because the corresponding areas are very distinct. Pergens figure 4, however, shows sufficiently distinct the small narrow >dorsal« areas, and the smaller dimensions of the fragment figured is evident from the fact, that the figure, which has the same size as the figure 3 is pictured under a larger magnifying power. —
Meliceritites sarissata Gregory.
Reptomultelea sarissata Gregory, Cretac. Bryozoa, p. 322, i)I. XVI, lig. 7. (PI. II, figs. 1—3.)
The Zooecia which are divided by very narrow more or less distinct marginal ridges, are generally rhombic, about twice as long as broad, and the convex or saddle-shaped suboral area, which is about of the length of the aperture, is strongly, almost vertically ascending towards the latter. No inleroral tubercles. The aper- ture which together with the strongly developed peristomial thickening takes up the
41
whole breadth in the distal part ol' the zooeciuin is about a third [)art longer than broad, and provided with a distinct and sharply defined but narrow oral ledge. It is roundedly triangular with a pointed distal part, and the arched lateral margins which are somewhat incurved distally are more or less converging proximally. The prieoral tubercle either forms a large rounded swelling or a more or less de- veloped beak-shaped projection. The convex or saddle-shaped distally pointed oper- culum shows a flabelliform striation.
The Heterozooecia which are spread among the zooecia in rather scarce num- bers are much longer than the latter. The aperture consists of a broad proximal part with distally converging lateral margins and a generally much longer (some- times more than twice as long) narrow distal part with allmost parallel or verj' little converging lateral margins. The mandible is distinctly convex not only from side to side, but also proximally distally.
Ooecia have not been found.
The Kenozooecia have been found spread among the zooecia in scarce numbers singly or more together.
The Closure. A distinct closure has not been found.
The Regeneration. There has been found no regeneration in the fragment examined.
The Colonies are composite, and the fragment examined is a multilayered lamina fixed to a piece of flint from Chatham or Luton (middle chalk).
This species is evidently related to Mel. sartliacensis.
Meliceritites Sartliacensis d'Orbigny.
Reptelea Sartliacensis d Orbigny, Bryoz. Cret. p. 640, pi. 604, figs. 9-10, pi. 738, fig. 15.
(PI. I, figs. 1-2.)
The Zooecia, which are divided by distinct marginal ridges are more or less regularly rhombic, as a rule double as long as broad, and the suboral area which is often somewhat convex is as long as or a little shorter than the aperture. No lateral tubercles. The triangularly rounded aperture which is a little longer than broad has a narrow obliquely immersed oral ledge, and together with the well-de- veloped peristomial thickening it takes up the whole breadth in the distal part of the zooecium. Its distal end is strongly projecting in the shape of a robust roun- ded beak (the prseoral tubercle). The convex operculum shows a faint striation, and as a rule most of its pores are arranged in two distally converging longi- tudinal belts.
The Heterozooecia which are in most cases a little longer than the zooecia are spread among the latter in rather large numbers, and are provided with a trian- gular aperture which may sometimes be twice as long as broad, sometimes only a little longer. It has a broad proximal margin, and the two somewhat incurved lateral margin are strongly converging towards the narrow roundedly pointed distal
IJ. K. I). Viilensk. SelsU. Skr., 7. Riekke. naturvideask. tij^ iiKitbein. Aid. \. 1. e
i2
end. No lateral thickenings. In a large number of the heterozooecia I have found a calcareous mandible which is strongly arched not only from side to side, but also proximally distally.
Ooecia have not been found.
Kenozooecia of the same form and size as the zooecia have been found spread among the zooecia in very scarce numbers.
A Closure effected by means of a concave lamina has been found in a few zooecia.
A Regeneration has not been seen.
The Colonies are composite, and the only fragment examined is a hollow three- layered expansion from le Mans (Cenonianian).
Meliceritites mici'opora d'Orbigny.
Meliceritites micropora d'Orbignj', Bryoz. Cret. p. 624, pi. 737, figs. 4 — 7.
— — Pergens, Revision d. Bryoz. p. .'597.
Nodelea micropora Gregory, Cret. Brjoz. p. 313.
(PI. Ill, fig. 10.)
The Zooecia (long 0,3 — 0,5) which are of very variable size are hexagonal-ovate, about twice as long as broad, convex and divided by distinct furrows in the bottom of which there may be found very narrow and indistinct marginal ridges. The half-elliptical aperture, the length of which is often contained about three times in the length of the zooecium, is not provided with a distinct peristomial thicke- ning nor with a distinct oral ledge. The convex operculum shows a distinct fla- belliform striation.
Heterozooecia have not been found.
The Ooecia. A single elongate ooecium has been found.
The Kenozooecia. A few of these zooids have been found among the zooecia.
A Closure of the primary zooecia has not been found.
The Regeneration takes place in great measure, but never in such a manner that the old aperture is filled by the new one. On the contrary the proximal half of the former is taken up by a concave lamina, the suboral area of the new zooecium, the distal half of which is strongly arched and provided with a small semicircular aperture, and the latter is at last closed by a concave lamina. The continued de- position of calcareous matter gradually effaces the limits between the old aperture and the suboral area of the new zooecium, and at a certain point of time only the rest of the small aperture and a more or less distinct depression proximally to the latter indicate that a regeneration has taken place.
The Colonies are incomposite, and the two fragments examined are cylindrical with 20 — 25 zooecia in each of the irregular transverse series.
Villedieu.
43
Meliceritites hexagona d'Orbigny.
Elea hexagona d'Orbigny, Bryoz. Cret. p. 633, pi. 738, figs. 1-4. (PI. V, figs. 3—5.)
The Zooecia, which are divided by well-developed marginal ridges, are rhombic or hexagonally rhombic, rarely twice as long as broad, and the half-elliptical or triangularly rounded aperture, which is as a rule longer than the suboral area together with the well-developed perislomial thickening takes up the whole breadth in the distal part of the zooecium. While the inter-oral tubercles may be developed in very different degree and may often be quite absent, the supra-oral one is large rounded and forms a robust beak-shaped projection. No distinct oral ledge. The convex operculum presents a distinct flabelliform striation.
The Heterozooecia, which are spread singly among the zooecia in rather scarce numbers are sometimes only a little longer than the latter, sometimes about twice as long. In the larger of them we may discern in the aperture between a broad proximal part, the lateral margins of which are converging distally, and a narrow distal part of different length with about parallel margins. In the shorter of them, however, the somewhat incurved lateral margins are gradually converging distally in their whole length. The mandible is arched both from side to side and proxi- mally distally.
Ooecia have not been found.
No Kenozooecia.
A Closure effected by means of a flat or concave lamina has only been di- stinctly seen in a small number of zooecia.
The Regeneration takes place in great measure, and in old colonies many aper- tures are very much projecting because the zooecia have been regenerated several times. There has also be found a regeneration of new heterozooecia in old ones.
The Colonies. I have examined a number of thick ribbon-shaped two-layered fragments from Vendome (zone with Crania ignabergensis).
Meliceritites plana d'Orbigny.
Scmielea plana d'Orhigny, Uryoz. Cret. p. 638, pi. 738, figs. 12-14. (PI. V, fig. 11.)
The Zooecia, which are more or less regularly rhombic and sometimes more than twice as long as broad, are divided by distinct ridges, and the suboral area which is as a rule more or less convex is much longer; sometimes about twice as long as the aperture. No distinct tubercles. The half-elliptical or triangularly rounded aperture which is a little longer than broad together with the well-devel- oped peristomial thickening takes up the whole or almost the whole breadth in the distal part of the zooecium. No distinct oral ledge. The convex operculum shows a flabelliform striation.
6*
44
The Heterozooecia, which are spread among the zooecia singly or in groups, have the same length as these, but the obliquely ascending distal end is provided with a small elongate triangular aperture the length of which is contained four lo five times in the length of the whole heterozooecium. The fissure-like opening is bor- dered by two inwards obliquely descending thickenings.
Ooecia have not been found.
Kenozooecia have not been found in the two small fragments examined.
The Closure starts by the formation of a number of processes which rise from the margin and grow together in a more or less irregular manner, thus forming at a certain point of time a calcareous cover perforated by 3 — 5 hollows which later get closed.
The Regeneration. I have seen a few cases of regeneration both of zooecia and of heterozooecia.
I have examined two small laminar fragments one of which has only the lo- cality France while the other which I have bought from Mr. W. Gamble is from St. Antoine du Rocher. Under the name of Semielea plana Mons. Filiozat has sent me three small fragments of another species which with the same right as the present might be referred to Semielea plana d'Orb. The zooecium and the aperture have the same form and structure, but the closure is elTected by means of a concave lamina, and in one of them I have found a heterozooecium a little longer than the zooecia and the aperture of which has about the same form as in that figured in pi. II, fig. 9.
Meliceritites cenomana d'Orbigny.
Nodclea cenomana d'Orbigny, Bryoz. Cret. p. 609, pi. 761. figs. 11 — 13. IPI. Ill, figs. 17, 18.)
The Zooecia, which are not twice as long as broad, are rhombic or hexagonally rhombic and divided from each other by the well-developed peristomial thickenings together with the tubercles which are as a rule well-developed and sometimes very large. The half-elliptical or triangularly rounded aperture, which together with the peristome takes up the whole breadth of the zooecium in its distal part, is half a time longer than broad, much longer than the suboral area, and the supra-zooecial tubercle forms a more or less developed, sometimes very robust beak-shaped pro- jection. No distinct oral ledge. The convex operculum is provided with a flabelli- form striation.
The Heterozooecia which seem to be very rare are much larger than the zooecia and provided with a very large (juadrangularly rounded aperture which is about twice as long as the suboral area. No lateral thickenings.
Ooecia have not been found.
No Kenozooecia.
45
The Closure takes place by means of a concave or flat lamina placed some way within the aperture.
The Regeneration. I have found a few zooecia regenerated.
I have examined two small well conserved fragments from le Mans (Ceno- manian), lent me by Dr. Pergens, and in these a number of the closure-plates and of the opercula have undergone a similar more or less complete decalci- fication as that found in Mel. Lorieri.
Meliceritites lainellosa d'Orbigny.
Elea lamellosa d'Orbigny, Bryoz. Cret. p. ()3'2, pi. (525, figs. 11 — 15. - Pergens, Revision p 398.
non Cea lamellosa d'Orbignj', Hryoz. Cret. p. 1007. pi. 787, figs. 11 — 13. Elea lamellosa Gregory, Crctac. Bryoz. p. 299. (PI. Ill, figs. 1-9)
The Zooecia which are as a rule rhombic or hexagonally rhombic and moslly twice as long as broad may be concave, flat or even a little convex and are di- vided from each other by more or less distinct ridges, the development of which may vary greatly even in the same colony. A more or less prominent tubercle may be developed not only at the distal end of the zooecium but also at the proximal corners of the aperture, and when the latter are placed in contiguous transverse series the tubercles of two adjacent apertures when sufficiently near to each other often fuse together into a single one. The development of the tubercles, however, is subject to great variation even in the same colony. The aperture the length of which is in most cases contained at least twice in the length of the whole zooecium takes up the whole breadth of the zooecium in its distal part and lacks an oral ledge, but is provided with a strongly developed peristomial thickening. It is half-elliptical or triangularly rounded and always longer than broad, but the relation between the length and the breadth is subject to rather great variation, and sometimes it is almost half a time as long as broad. The operculum shows a distinct flabelliform strialion, and the greater part of its surface is more or less distinctly flattened.
The Heterozooecia, which are scattered over the colony in rather large numbers, partly singly, partly in groups up to four are in most cases longer and narrower than the zooecia, and their distal end is more or less obliquely ascending. It is provided with an elongate, roundedly triangular, dislally protruding aperture, the lateral parts of which are covered by two very narrow, elongate triangular lateral processes between which is seen an opening in the shape of an inverted T.
Ooecia have been found.
Kenozooecia have not been found.
The Closure. I have not found a distinct case of closure in any zooecium, but in old heterozooecia.
J6
The Regeneration takes place both in the zooecia and the heterozooecia, and in the former in a double manner, as an old zooeciiim may be replaced either by a new zooecium or by a heterozooecium, and in the first case there is seen a new oral margin within the old one. If an old zooecium is replaced by a heterozooecium (figs. 1, 3, 4,5) the free, distal part of the latter gets another form than the corresponding part of the common heterozooecia, especially when it takes up the whole of the zooecial aperture, as in that case it must of course be much broader. The free part, of such a heterozooecium is very much protruding, and one may discern between a posterior strongly convex, from side to side somewhat compressed, sometimes a little saddle-shaped surface and the frontal surface which as a rule forms a right angle with the frontal area of the old zooe- cium. We may compare this free part with a half somewhat compressed cone which rests on the surface of the cut and the basal surface of which wears the aperture. — Sometimes the named part does not take up the whole aperture (fig. l) and in that case the difference of form is not so great. When a new heterozooecium is formed in an old one its free distal part, which is often vertically ascending par- tially covers the corresponding part of the old heterozooecium, the tip of which is seen protruding distally to it (figs. 5, 6, 7|.
The Colonies have the form of free two- or more-layered laminae. Of this spe- cies I have examined or large number of fragments from Villcdieu (Coniacian).
Meliceritites undata d'Orbigny.
Melicei-itites undata d'Orbigny, ISryoz. Cret. p. 625, pi. 737, figs. 11 — 14. non Meliceritites undata Gregory, Cret. Bryoz. p. 340, pi. XV, figs. 2—4, pi. XVI, fig. 3.
(1^1. IV, figs. 9-17.)
The Zooecia, which are divided by distinct more or less prominent ridges, are about twice as long as broad, and the suboral area generally presents a saddle- shaped concavity in the direction proximally distally. More or less developed tu- bercles. The half-elliptical aperture which is a little longer than broad lacks a distinct oral ledge, but is provided with a well-developed peristomial thickening, the lateral parts of which generally widen proximally, and these widened lateral parts belonging to two adjacent zooecia often coalesce with the interoral tubercle into a large rounded projection (fig. 17). The convex operculum is provided with a flabelliform strialion, and with very few exceptions with 1 — 4 short arched, more or less distinct impressions turning the concavity proximally. When only- a single impression is present it is seated in the proximal part.
The llelerozooecia which are scattered among the zooecia in rather small num- ber, but not rarely two or more together, are of the same size as the latter, and their obliquely ascending more or less projecting distal end is provided with an aperture of somewhat different form and size, the length of which may l)e con- tained 3 — 6 times in the length of the whole heterozooecium. It is generally narrow
47
(figs. 12, 13) but sometimes of a semi-elliptical form (fig. 12). In the best preserved specimens I have found two narrow lateral processes.
Ooecia have not been found.
No Kenozooecia.
A Closure effected by means of a concave lamina has only been found in a few cases (fig. 15).
The Regeneration takes place in great measure, and in many of the fragments examined the larger part of the zooecia have been regenerated either by new zooecia (figs. 11, 16) or by heterozooecia (figs. 10, 14).
The Colonies are incomposite, and the cylindrical branches bear c. 14 zooecia in each transverse series.
Numerous specimens from Fecamp (middle Senonian).
Meliceritites Vieilbanci d'Orbigny.
Setnielea Vieilbanci d'Orbigny, Bryoz. Cret. p. ii'Mi, pi. 637, figs. 7, 8. Klea Vieilbanci Gregory, Cretac. Bryozoa p. 300, fig. 33, pi. 738, figs. 5—9. (PI. 1, figs. 15, 16.)
The Zooecia, the dividing ridges of which are often very indistinct, are gene- rally about twice as long as broad, and their surface often presents a saddle- shaped concavity in the direction proximally distally. The broadly rounded, al- most semicircular aperture, which is provided with a narrow and generally indi- stinct oral ledge has a strongly developed peristomial thickening and sometimes takes up the whole breadth of the zooecium in its distal part. Its length is con- tained 3—4 times in the length of the zooecium. The operculum is very convex and presents a distinct flabelliform striation.
Heterozooecia have not been found.
Ooecia have been found by Gregory.
No Kenozooecia.
The Closure is effected by means of a concave lamina (fig. 16).
The Regeneration. In most fragments examined a number of zooecia have been regenerated, but the protruding end of the new zooecium only in a few cases pre- sents a half-elliptical aperture, the apertures being in most cases either perfectly closed or transformed into a narrow fissure which is no doubt the rest of the ori- ginal aperture.
The Colonies are hollow free irregularly branched expansions with cylindrical or compressed branches. Some of the fragments examined show a beginning new layer in the form of one or more circular patches of different extension.
A number of fragments from Villedieu (Coniacian) and Bruille-Ponce (Turonian).
48
Meliceritites diirobrivensis Gregory.
Nodelea durobrivensis Gregory, Cret. Bryoz. p. 310, pi. XIV, figs. 4 — 13. (PI. IV, figs. 1- G, 8.)
The Zooecia which are divided by well-developed marginal ridges are generally rhombic or hexagonally rhombic, longer than broad, and the very concave snbora! area takes up almost half the length of the whole zooecium. No distinct tubercles. The large aperture, which is surrounded by a strongly developed and very often obliquely ascending peristome, is a little longer than broad, and the lateral mar- gins are generally distinctly converging proximally. No distinct oral ledge. The distal half of the aperture together with the peristome generally takes up the whole breadth of the zooecium. The very convex operculum is provided with a distinct llabelliform striation.
The Hcterozooecia, which in most colonies are present in large numbers, rarely attain the size of the zooecia, and in most cases they are much smaller, sometimes only attaining half the length of the latter. They are rhombic very much concave and provided with a very small about half-elliptical aperture, the larger part of which is covered by a concave lamina, perforated by a narrow fissure, sometimes in the shape of an inverted T. In a number of them I have found an operculum of the same structure as that of the zooecia. Most of them are arranged in longi- tudinal series each consisting of 2 — 7 in such a manner that two succeeding hetero- zooecia are divided from each other by a pair of zooecia. In the more regular cases each two longitudinal series of hcterozooecia are divided by two longitudinal series of zooecia, and, therefore, there may be seen on the surface of a fragment as many as 6 longitudinal series of heterozooecia. However, the arrangement as well as the size and the number of the heterozooecia is subject to great variation, and sometimes there may be seen groups of up to 14 adjacent heterozooecia.
Ooecia have been found.
No Kenozooecia.
A Closure by means of a concave lamina is rarely seen.
The Regeneration takes place in great measure, and the zooecia may be regene- rated either by a new zooecium (figs. 4, 8) or by a heterozooecium (fig. ;J). In the latter case the part of the heterozooecium enclosing the aperture maj' be more or less projecting, and the aperture of the new heterozooecium sometimes forms a right angle with the suboral area.
The Colonies are incomposite, and the fragments examined are cylindrical with 8 — 10 zooecia in each transverse series. I have examined a large number of frag- ments from Chatham (middle chalk) and Fecamp (middle Senonian).
49
Meliceritites durobrivensis, var. parviarmata Greg.
Meliceritites parviarmata Gregory, Cretac. Hryoz. p. 340, pi. XV, fig. 1. (PI. IV, figs. 7, 19—21.)
The Zooecia, which are divided by strongly developed marginal ridges are of ralher different form and length, hut in most cases they are twice as long as broad or even longer. No distinct tubercles. The aperture, the form of which is some- what variable, may sometimes be almost half as long as broad, and the two lateral margins are in most cases more or less distinctly parallel. There is found a strongly developed peristomial thickening, and a very convex operculum with llabelliform striation. No distinct oral ledge.
The Heterozooecia which are present in large numbers are of very different form and size, the length of the smallest being contained 6 — 7 times in the length of the zooecia, while the larger of them may sometimes attain the length of the latter. Their distal end which is more or less projecting and sometimes forms allmost a right angle with the suboral area contains an aperture of the same form as that of the zooecium, but the larger part of it is closed by a concave lamina which is provided with an opening in the shape of an inverted T. Their distri- bution is very different as they are sometimes placed between the apertures of a number of adjacent zooecia, while in other cases they are irregularly heaped to- gether, partly around the distal end of a zooecium (fig. 7), partly between a num- ber of zooecia, and in some fragments of colonies which have been growing on shells and which are provided with an incrusting base the larger part of the latter is formed by heterozooecia. While that portion of this incrusting layer which immediately surrounds the proximal part of the free stem is composed chiefly of zooecia its peripherical part almost entirely consists of heterozooecia which there- fore here seem to play a similar role as the kenozooecia forming the incrusting base of a 7?e/e/jora-colony. One of the incrusting bases examined not only covers the one surface of a small fragment of a shell, but also a large part of the oppo- site surface, and here forms an extension 10"'™ long and 6""" broad, in which there is only found 3 zooecia.
An Ooeciiim has been fouVid in one of the incrusting bases.
No Kenozooecia.
A Closure of the zooecia by means of a concave lamina has only been found in a few cases (fig. 7).
The Regeneration. There is found a regeneration both of new zooecia in old ones and of heterozooecia in zooecia (fig. 7).
I have examined a few fragments from Chatham, Luton, Gillinghani (middle chalk) and Evreux (middle Senonian).
n. K. D. VIdensk. Selsk. SUi-.. 7. Rskke, n.ilurvidcnsk. it]i malhcm. .Kfii. X. 1.
50 Melicerilites punclata d'Oibigny.
Myriozouni punctatum d'Orbigny, Bryoz. Cret. p. 0()3, pi. 7.S3. ligs, 4—7. (PI. V, figs. G-8.)
The Zooecia, which are not divided by marginal ridges, are provided with more or less, large and deep pits, the number of which increases with age, and in old zooecia they are divided from each other by a rich net-work of prominent ridges. The half-elliptical aperture which lacks a distinct oral ledge is provided with a generally strongly developed and much raised peristomial thickening. The convex operculum presents a flabelliform striation.
The Heterozooecia, most of which are longer than the zooecia, are spread among the zooecia in rather large numbers, either singly or two placed near together. The elongate aperture is in the smaller of them triangular the two lateral margins converging distally in their whole length, but in the larger the distal half is bor- dered by two allmost parallel lateral margins. The concave surface distal to the inner aperture has no lateral projections or thickenings. In a few heterozooecia I have seen a calcareous mandible (fig. 8).
Ooecia have not been found.
No Kenozooecia.
A Closure by means of a concave lamina has only been seen in a few zooecia.
The Regeneration. While a distinct regeneration of new zooecia in old ones has not been seen, there can be no doubt that the form and position presented by some of the heterozooecia in a single of the colonies examined can only be explained from a regeneration of new heterozooecia in old ones. While the aperture of the common heterozooecia is about parallel to the axe of the colony the aperture of these heterozooecia forms an angle of up to 130 degrees with the surface of the latter, and in consequence hereof they are provided with two large, triangular or trapeziform lateral surfaces which show the same pitied appearence as the zooecia. How many times the regeneration has taken place in the single heterozooecia cannot he seen he- cause of the rich deposition of calcareous matter which goes on over the surface of the whole colony and to which the pitted appearance is due.
The Colonies are incomposite, and the examined cylindrical fragments are pro- vided with 10—14 zooecia in the transverse series.
I have examined a number of specimens from Vendome (zone with Crania ignabergensis).
Melicerltites Dollfusi Pergens.
Meliceritites Dollfusi Pergens, Hevision d. Bryoz p. 395, pi. XIII, fig. 4. Melicerltites lonsdalci Gregory, Cret. Bryoz. p. 335, pl. XV, figs. 5-9. (PI. IV, fig. 23.)
The Zooecia which are as a rule twice as long as broad are divided by more or less distinct marginal ridges, and the concave or saddle-shaped suboral area
51
ascends towards the strongly projecting distal part which rises in the form of a short tube. No tubercles. The aperture which lacks a distinct oral ledge and pre- sents no peristomial thickening') ranges between semicircular and triangularly rounded, and sometimes the distal end may be more or less distinctly pointed. The convex operculum presents a distinct flabelliform strialion.
The Heterozooecia which may be twice as long as the zooecia are provided with a concave suboral area and a very elongate aperture, the breadth of which is contained about three times in the length. It attains its largest breadth at the di- stal margin, and the two lateral margins which are incurved in their middle part distally run together in a curve. There are no lateral thickenings. They are as a rule present in scarce numbers, but not rarely there may be found 2-4 placed near each other in the same transverse series, and in a single case I have found 7 forming an irregular, interrupted transverse row.
Ooecia have been found.
No Kenozooecia.
The Closure is effected by means of a concave lamina.
A Recjeneration has not been found in the fragments examined.
The Colonies are incompositc, and the examined cylindrical fragments have 10 — 12 zooecia in each transverse series. One of them which is fixed to a frag- ment of a shell is provided with a basal expansion consisting of zooecia and hetero- zooecia of the same kind as those found in the free cylindrical part. The hetero- zooecia of this specimen (from Lulon) are a little different from those found in the others as the lateral margins of (he aperture are not incurved in the middle but converging distally.
Chatham, Gillingham, Lulon (middle chalk) Fecamp (middle Senonian).
Meliceritites Dollfusi, var. tubuliformis n.
(PI. V, figs. 9, 10.)
Of this form which I provisionally refer to M. Dullfiissi I have only seen a single fragment 4""" long and 1 "i"' broad. The most conspicuous difference is the length of the tubular distaf pari, which is about as long as the suboral area. Sometimes the frontal part of it is divided from the rest by two more or less di- stinct marginal ridges. The obliquely ascending aperture is half-elliptical or trian- gularly rounded, and the very convex operculum is distinctly striated. The Hetero- zooecia of which there is found three do not differ from those in M. Dollfusi and that seen in fig. 10 which seems lo be shorter is not (|uite correctly figured as the distal part was broken off. — Evreaux (middle Senonian).
M When Gregoij' in tlii.s species speaks about "well raised' peristomes, lie confounds a raised peristome with a freely projecting distal part of a zooecium.
LITERATURE.
1. GoLDKUSs, A. Petrefacta Germanise: Abbildungen und Beschreibungeii der Petrefacten Deutschlands
und der aiigrenzenden Lander. Dusseldorf, 1826 — 1840. [Bryozoa, Vol. 1, pp. 2H-41, pis. Vlll-Xll.]
2. Milne-Edwards, H. Note sur un nouveau genre de Polypiers fossiles, de la famille des Eschariens,
nommc Melicerite (Annales des Sciences Naturelles, Zoologie, [21, VI, 183G, pp. 34.') — 47, pi. 12, fig. I'J).
3. Hagenow, F. v. Monographic der Riigenschen Krcide-Versteinerungen (Leonhardt und Hronn's Neues
Jahrbuch fijr Mineralogie . . . 183'J, pp. 2'>:i 29(5, pis. IV, V. [Bryozoa pp. 262— 2i)6] ; ibidem 1840, pp. 631-672, pi. IX. [Bryozoa, 643—649.]
4. — Bryozoa, Geinitz' Grundriss d. Versteinerungskunde. Dresden 1846, 817 pp., 26 pis. [Bryozoa,
pp. 586—635, pi. XXIII b].
5. Die Bryozoen der Maastrichter Kreidebildung. Cassel, 1851. XVI ^111 pp., 12 pis.
6. RoEMER, F. A. Die Versteinerungen des norddeutschen Kreidegebirges. Hannover 1840, 4lo, 40 pp.,
12 pis. [Bryozoa, pp. 11-25, pi, V.|
7. Orbigny, a. d' Paleontologie Francaise. Description des animaux invertebres. Terrain Cretacc.
Tome cinquicme. Bryozoaires. Paris. 1850—1852. Text, 1192 pp.. Atlas, pis. 600-800.
8. Hamm, H. Die Bryozoen des Maastrichter Obcr-Senon. 1 Theil: Die Cyclostomen Bryozoen. Berlin,
1881. 47 pp., 8°.
9. Pergens, E. et Meunier, A. La faune des Bryozoaires Garumniens de Faxe. (Annales de la Societe
Royale de Belgique, Bruxelles, XXI, 188(i, Mcmoires, pp. 187-242, pis. 1X-XIII|.
10. Mahsson, Th. Die Bryozoen der weissen Schreibkreide der Insel Kiigen (Pal?eontologische Abhand
lungen herausgegeben von Dames und Kayser. Band IV, Heft 1. Berlin, 1887, 112 pp., 10 pis.
11. Pergens, E. Revision des Bryozoaires du Cretace figures par dOrbigny (Memoires de la Societe
Beige de Geologic, de Paleontologie et d'Hydrologie, Bruxelles, III, 1889, pp. 305-400, pis. XI- XIII).
12. Waters, A. W. On Chilostomatous characters in Melicertitida? and other fossil Bryozoa. (Annals
and Magazine of Natural History, [6[, VllI, 1891, pp. 48—53, pi. VI). r.'a. Hakmer, S. F. The British species of Crista (Quarterly Journal of microscopical science [n. s.], XXXII, 1891. pp. 127-181, pi. XII).
13. Canu, F. Bryozoaires du Turonien de Saint-Calais (Bulletin de la Societe Geologlque de F"rance,
3e serie, T. XXV, 1897, pp. 737—754, pi. XXII).
14. Gregory, J. W. Catalogue of the fossil Bryozoa. The Cretaceous Bryozoa, vol. I, 1899.
15. Canu, F. Bryozoaires fossiles (Bulletin de la Societe Geologique de France, 4e serie, T. II, 1902,
pp. 10-14.
16. Levinsen, G. M. R. Studies on Bryozoa (Videnskabelige Meddelelser fra den naturhistoriske For-
ening i Kebenhavn, 1902, pp. 1—31).
17. — Sur la regeneration totale des Bryozoaires (Bulletin de I'academie royale des sciences et des
lettres de Daneraark, 1907, Nr. 4, pp. 152-159, pi.).
18. — Morphological and systematic studies on the cheilostomatous Bryozoa, pp. I — VII, 1 — 427, 27
pis. 4to Copenhagen 1909.
19. Lang, \V. D. The replant Eleid Polyzoa (Geological magazine, dec. V, vol. Ill, 1906, pp. 60— 69). —
Plate I.
(The numbering of the plates is to be changed into X 1.)
I'lalc I*).
Fig. 1. Meliceritites sarthacensis d'Orb. Distally is seen a lieterozooecium wliicli has been regenerated and proximally one provided with a calcareous mandible. X 34.
— 2. The same species. There is seen two heterozooecia, one of them with a calcareous mandible.
X 34.
— 3. Meliceritites magnifica d'Orb. Of the six zooecia the four have been regenerated, and the aper-
tures of the new zooecia have been closed by a concave lamina. (Not well executed). > 34.
— 4. The same species. Four of the zooecia and three of the heterozooecia have been regenerated
and some of them twice. The aperture of the new zooecium at the rigth side has been closed by a concave lamina. X 34.
— 5. The same species with ooecium. X 20.
— 6. The same species with another form of ooecium. X 20.
— 6a. The same species. Two of the zooecia are provided with an operculum, and two are closed by
a lamina presenting a ±-shaped opening. X 34.
— 7. The same species. There is seen two different forms of closure. X 34.
— 8. The same species. Different forms of closure from the same colony. X 47.
— 9. The same species. A regenerated zooecium with operculum. X 47.
— 10. The same species. A transverse section through a heterozooecium to show the lateral jjrocesses
covering the larger part of the aperture. X 47.
— II. Meliceritites gothica nov. nom. Three zooecia with opercula and one regenerated which has been
replaced by a heterozooecium. X 34.
— 12. The same species. There is seen three kenozooecia, three zooecia with o|)ercula, tliree closed
heterozooecia and three zooecia, all of which have been regenerated by means of hetero- zooecia. >' 20.
— 13. A zooecium of the same species. X 34.
— 14. The same species. The aperture is closed by a flat lajnina which has arisen from the free
edge of the oral ledge. X 34.
— 15. Meliceritites Vieilbanci d'Orb. Five of the zooecia have been regenerated X 34.
— 16. The same species. There are seen four zooecia with opercula, two regenerated, two open and
two closed by a concave lamina. X 34.
— 17. Meliceritites trifolium n. sp. Five zooecia with opercula. X 47.
— 18. The same species. There are seen six heterozooecia, and two zooecia regenerated bj' means of
heterozooecia. X 47.
— 19. The same species. There is seen a heterozooecium. and three zooecia regenerated by means of
heterozooecia. (In one of them the two lateral processes have been broken off.) X 47.
*) The present is the las! plate lithograplied by the e\celkiit artist Mr. C Cokdts, but (lie execution l)iars wit- ness to that he has not been able to lay the last hand on it before his death.
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Plate II
I'late II.
Fig. 1. Mcliceritites sarissala Greg. Two Kenozooecia and a heterozooeeium. X 34.
— 2. The same species. Zooecia with opercula. X 34.
— 3. Tlie same species. A heterozooeeium witli mandible, surrounded bj' kenozooecia. X 34.
— 4. Meliceritites angnlosa d'Orb. An ooecium. Villedieu. X 20.
— 5. Tlie same species. Two lieterozooecia of wliich tlie distal one has been regenerated by means
of a new zooecium, and tliereafter tlie remainder of the large aperture has been closed (compare with figs. 7 and 9). Villedieu. x 20.
— (). The same species. Regeneration of a heterozooeeium. The calcareous processes have not yet
been formed distally to the new heterozooeeium. Villedieu. X 34.
— 7. A new zooecium has been formed within an old heterozooeeium, and the rest of the aperture
has been closed, but the processes corresponding to those seen in figs. 5 and 9 are here very irregular. The zooecium is provided with a concave closure-plate which still has a small opening. Villedieu. X 34.
— 8. The same species. A heterozooeeium. Villedieu. X 34.
— 9. Regeneration of a heterozooeeium. Villedieu. X 34.
— 10. The same species. Fecamp. X 34.
— 11. The same species. Couture. X 20.
— 12. A zooecium in an old heterozooeeium. Villedieu. X 34.
— 13. The same species Chatham. X 34.
— 14. Two lieterozooecia from the same colon}', Couture. X 20.
— 15. The same species. At the left side of the heterozooeeium is seen a zooid intermediate between
a zooecium and a heterozooeeium. Fecamp. X 20.
— 16. A heterozooeeium with mandible. X Villedieu. X 20.
— 17. The same species.
— 18. Another heterozooeeium with a mandible the distal part of which has been broken off.
— 19. The same species Villedieu. X 34.
— 20. The same species. Regeneration of a heterozooeeium. Bruille-Ponce. X 34.
— 21. The same species. Villedieu. X 20.
— 22. Regeneration of a heterozooeeium. Villedieu. X 34.
— 23. Meliceritites yotliica, var. acuminata. X 34.
— 24. The same species. A heterozooeeium.
K. D. Vidensk. Selsk. Skr., 7 R., n-m Afd. VI, 9 [.G. M. R. LeuinsenJ.
PL II.
Levinsen del.
Pacht A Crone phototyp.
Plate III
1). U n Vlilensk. SelsU. SUr..7. R^i-lilie. iKilurvidensk. oM mulli.-ni. Al'.l X. 1.
Plate III.
Fig 1 Mclicerilitcs Idinellnsa d'Orb. Three zooecia with opcrcula, and two holerozooecia in old zooecia, the aperture of wliich is not wliolly talicn up by the new zooids. The lateral margins of the heterozooecial apertures are not distinct. > 34
— 2. The same species. Two regenerated zooecia with opercula and a hcterozooecium. X 34.
— 3. The same species. Four heterozooecia one of which takes up the whole aperture of an old
zooecium. Two of them are provided with a mandible. X 34.
— 4. The same species. Two heterozooecia in old zooecia. The aperture of the distal one is partly
closed. X 34.
— ,">. The same species. Four heterozooecia one of which takes up the whole aperture of an old
zooecium. The distal one on the left side has been regenerated. X 34.
— (). A regenerated heterozooecium. X 34.
— 7. The same species. Four regenerated zooecia, two of which are provided with opercula and
one with a closure-lamina. Three regenerated heterozooecia. X 34.
— 8. The same species. X 34.
— 9. The same species. An ooecium > 20.
— 10. Meliceritiles inicropora d'Orb. Three regenerated zooecia and two zooecia with opercula. X 34.
— 11. Meliceritiies Steenslrupi Pergens The hinder surface with the heterozooecia. X 20.
— 12. The same species. Three heterozooecia. X 34.
— 13. The same species. Two zooecia' with opercula. X 34
— 14. Melicerilites nrmata n. sp. The hinder surface with kenozooecia and heterozooecia X 20.
— 15. The same species. A zooecium with operculum. X 34.
— 16. The aperture of a heterozooecium. X 34.
— 17. Melicerilites cenomana d'Orb. A heterozooecium. X 34.
— 18. The same species. >, 34.
— 19. Meliceritites Canui n. sp. The hinder surface with the heterozooecia. X 20.
— 20. The same species. Three heterozooecia. X 34.
— 21. The same species. Two zooecia with opercula. X 47.
— 22. A heterozooecium. X 47.
— 23. A heterozooecium the aperture of which is partially closed. X 47.
— 24. A heterozooecium with a very elongate aperture. X 47.
— 25. A heterozooecium tlie aperture of which is not far from being perfectly closed. X 47.
— 26. A zooecium with a closure-plate. X 47.
— 27. A heterozooecium which takes up the aperture of an old zooecium. X 47.
K. D. Vidensk. Selsk. Skr., 7 ft., n-m Afd. VI, 9 [G. M. ft. Levinsen].
HI.
Levinsen del.
Pm'ht ft Crone phototyp.
Plate IV.
Plate IV.
Fig. 1. Mclicerilites duiobrivciisis Greg Kivo zooccia with oijciiula aiui tliree lieU-iozooccia Iwo of which are provided witli opeicula. Cliatham. X 34.
— 2. The same species from Fecamp. Tliree hcterozooecia. X 34.
— 3. The same species. Two large heterozooecia and three zooccia \\liich have heeii icgeiicralcd \>y
means of heterozooecia. Luton. X 34.
— 4. The same species. A regenerated zooecium with opercuUim. (Chatham. X 34.
— 5. The same species. (Chatham. X 34.
— (i. The same species. A zooecium the aperture of which is almost perfectly closed hy a concave
lamina. There is only left a small opening in the distal half, ('.hatham. X 34.
— 7. Mcliceritiles duiohrivensis, var. pannarmiita. 'Ihere is seen a number of small heteiozooecia
two of which in old zooecia. one zooecium with opereuliini and another with a concave closure-lamina. Gillingham. >: 34.
— S. Mcliceritiles durobrivensi.i Greg. There are seen four regenerated zooecia, the distal of which
has been regenerated twice while the two at the left side have been rcgcnciatcd several
times. Chatham. >' 34. !). Melireritiles iiiidala d'Orb. X 34. 10 The same species. Three zooecia have been regenerated by means of heterozooecia. X 34. 11. The same species. Two regenerated zooecia with opercula.
— 12. The same species. Three heterozooecia one of which is intermediate between a lutcrozooccium
and a zooecium. ',■ 34.
— 13. The same species. Two heterozooecia. X 34.
— 14. The same sjiecies. A zooecium regenerated by means of a hetcrozooeciuni. X 34.
— 15. The same species. A zooecium v\ith a concave closure-lamina which l,s not yet clo.sid in the
middle. X 34. I(). The same species. A regenerated zooecium with operculum. > 34.
— 17. 1 he same species. X 34.
— IcS. Mcliceritiles Luticri d'Orb. Two zooecia with opercula. > 34.
— lit. Mcliceritiles durohrii'cnsis, var. parviarmala. A [jortion of the inciusting base, consisting
chiefly of heterozooecia. Chatham or Luton X 20.
— 20. Two heterozooecia from the same colony. X liK.
21. The same form. A portion of a two-layered colony with numerous heterozooecia. Basin de Paris. X 34.
— 22. Mcliceritiles peiilaijouitm n. sj). Three heterozooecia. Tullstorp. X 20.
— 23. Mcliceritiles Dollfiisi I'crgcns. One of the two heterozooecia shows a calcareous maMclible.
(jillingham. , 20.
A'. D. Vidensk. Selsk. Skr., 7 R., n-m Afd. VI, 9 [G. A/. H. LevinsenJ.
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Plate V
Plate V.
Fig. 1. }feliceritiles dichotoma d'Orb. Four zooccia with opcicula and three hetciozooecia the aper- tures of whicli have been covered by coucave closiire-phites. >, 34.
— 2. The same species. There is seen a regenerated zooccium and two zooecia witli closure plates.
X 34.
— 3. Mcliceritites hexaijoiut d'Orb. X 34.
— 4. The same species. The two zooecia on the left-hand side have been regenerated twice, and the
peculiar appearance of the unusualh' large zooecium to the right must no doubt be ex- plained by a repeated regeneration together with the circumstance that the limits between the different peristomes have been effaced. >; 34.
— 5. The same species. A heterozooecium with mandible. X 34.
— 6. Meliceiitites punctata d'Orb. The zooecia with opcrcula. > 34.
— 7. The same species. A heterozooecium. X 34.
— 8. The same species. A heterozooecium with mandible. X 34.
— 9. Mcliceritites Dollfusi Pcrgens. var. tnlniliformi!! n. A heterozooecium ami a ZDoccium with
operculum
— 10. The same species. > 34.
— II, Meliceritites plana d'Orb. Two heterozooecia. France. , 20.
— 12. The same species. Three zooecia with opcrcula and si.\ with closure. St. Antoinc do Hoclier.
X 34.
— 13. Meliceritites scioamata Marsson. One of the smaller heterozooecia. Moen (Denmark) 34.
— 14. The .same species. A zooecium in an old heterozooecium. X 34.
— 15. The same species. A new heterozooecium in an old one. X 34.
— 1(). i'lie same species. A heterozooecium. X 34.
— 17. The same species. A heterozooecium with a broader aperture and with maiulible. > 34.
— 18. Meliceritites Roemcri v. Hag. Tullstorp. X 20.
— 19. The same species. Distally is seen a small heterozooecium in an old zooecium, to the left a
new zooecium in an old one and to the right a concave closurc-lamiiKi. 34.
— 20. The same species. Three zooecia with a distinct oral ledge, X 34.
— 21. A kenozooecium and a small heterozooecium. X 34.
— 22. A small heterozooecium. >, 34.
— 23. Two .small heterozooecia with a more elongate aperture. > 34.
— 24. A small heterozooecium with a niiicli larger aperlnre. , 34.
K. D. Vidensk. Selsk. Skr., 7 R., n-m Afd. VI, 9 [G. M. K. LevinsenJ.
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Plate VI.
Plate VI.
l-'ig. 1. MeUcerititcx tuberculata d'Orb. There are seen eight kenozooecia, two zooecia with opcicula and two heterozooecia one of which has been regenerated. Basin de Paris. )< 34.
— 2. The same species. There is seen a heterozooecium with mandible. France. X 47.
— 3. The same species. Five zooecia and a kenozooecium surround an ancestrula of which only the
aperture is seen. Uasin de Paris. X 47.
— 4. Meliceriiiles semiliina d'Orb. All the zooecia are provided with a flat closure-plate, which rises
from the free edge of the oral ledge. X 34.
— 5. The same species. Two zooecia with opercula. X 34.
— 6. The same species. Two heterozooecia. X 34.
— 7. Meliceritiles Filiozati n. sp. There are seen the apertures of three ancestrulae, two kenozooecia
and two heterozooecia. Fecamp. > 34.
— 8. Four zooecia and a kenozooecium surround the ancestrula of a future colnny. Fecamp. X 34. ^ 9. The same species. There are seen two heterozooecia and two kenozooecia. Fecamp. X 34.
— 10. The same species. One of the two zooecia is provided with a closure-plate which rises at a
deeper level than the oral ledge. Fecamp. X 34
— 11. Meliceritiles pijrenaica d'Orb. All the apertures which are of very different form and size seem
to have been regenerated, perhaps several times. Tours. X 20.
— 12. The same species. The suboral area is only represented by the pits. Villedieu. X 34.
— 13. The same species Two zooecia with opercula The beak and the proximal tooth are distinct.
Villedieu. X 34.
— 14. The same species. The two strongly prominent zooecia seem to have been regenerated. Ville-
dieu. X 20.
— 15. The same species. Three zooecia with opercula. The strongly developed suboral areas are
convex owing to a rich deposition of calcareous matter, and the pits have almost vanished. Villedieu. X 34.
— 16. The same species. All the zooecia have no doubt been regenerated. Villedieu. X 20.
— IV. The same species. Zooecia from the distal end of a colony. The oral ledge and the proximal
tooth are distinct, and only a single zooecium has been regenerated. Villedieu. X 20.
— 18. The same species. There are seen a heterozooecium and an operculum. Most zooecia have been
regenerated. Villedieu. X 20.
— 19. The same species. The suboral area is short and broad and provided with two lateral pits.
Villedieu. X 34.
— 20. The same species. The zooecia which have no doubt all been regenerated are placed in all
directions. Villedieu. X 20.
— 21. The same species. Six zooecia surrounding a heterozooecium. They seem all to have been
regenerated. Villedieu. X 20.
K. D. Vidensk. Selsk. Skr., 7 R., n-m Afd. VI, 9 [G. M. R. LeuinsenJ.
VI.
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Plate VII
1). K. n. Vidensli. Selsk. Skr.. 7. H:ukke, niilurvidensk. Oji matliem. AM. X. 1.
I'lnte VII.
Fig. I. Meliceritites pulpebrosa iiov. nom. Two zooi-ciii with ;i convex closuiv-plntt- X 34.
— U. Tlie same species. A zooecium with a flat closure-plate, x 34.
— '^. The same species. Four zooecia with opercula. X 34.
— 4. The same species. A zooecium with a beginniu;,' convex closure plate. X 34.
— 5. The same species Five zooecia with a convex ciosure-plate. The proximal part of the closure
lias in three of the zooecia been directed obliquely inwards. >; 34. f). A zooecium with a distal convex and a proximal concave closure-plate. X; 34. 7. Three zooecia with a beginning distal and a well-developed proximal closure-plate. The proximal
margin and a porliou of the lateral margins of the aperture are still seen. X 34.
— 8. A zooecium with a convex closure-plate. X 34.
— 9. Two zooecia in which both the distal and the proximal part of the closure are well-developed.
X 34.
— 10. Meliceritites durobrivensis Greg. A transverse section through a branch. Chatham. X 34.
— 11. A portion of the atrial ring in the ooeciuni of Crista ebitrnea. Denmark. X 1"5
— 12. The distal part of the ooeclum of Crista eburnea after the removal of the frontal wall. The
atrial ring is seen. X 66.
— 13. An opened, ooecium of Mel. magnifica after the adzooecial wall has been dissolved. The zooids
covered by the ooecium are in this case completely developed. X -0.
— 14. Au opened ooecium of Mel. magnifica after the adzooecial wall has been dissolved. The zooids
covered by the ooecium have no calcified frontal wall. X 20.
— 15. An opened ooecium of Met. magnifica X 20.
— 16. A fragment of Mel. magnifica showing three different superficial laj'ers. X !•
17. An opened ooecium of Mel. magnifica, which belongs to the growing end of a superficial layer and the distal half of which covers an elder portion of the colony. The adzooecial wall has been dissolved. X 20.
— 18. An open ooecium of Mel. magnifica in the proximal part of which is seen a zooecium and
three heterozooecia besides the aperture of the gonozooecium. It is likely to suppose that the former have originally been cowered by a bulging part of the adzooecial wall, which has later been destroyed. X 20.
— 19. Mel. magnifica. A transverse section of a branch with an ooecium. X 14.
— 20. An open ooecium of Mel. lamellosa dOib. The adzooecial wall together with a part of the
underlying zooecial tubes have been dissolved. Xx 20.
— 21. An opened ooecium of Mel. lamellosa. The proximal half of the atrial ring is seen. > 20.
— 22. Mel. lamellosa. The distal end of an opened ooecium with the proximal half of the atrial ring.
X 34.
— 23. Mel. lamellosa. A transverse section of a colon}'. X 20.
— 24. Sptropora micropora d'Orb. A transverse section. > 20.
— 25. Entalophora Roemeri n. sp. A transverse section. >, 14.
— 26. Zooecia of Ent. Roemeri. X 20.
— 27. An opened ooecium of Mel. angulosa d'Orb. X 20.
— 28. Mel. angulosa d'Orb. The distal end of an opened ooecium with the pioxinial half of the
atrial ring. X l>(>.
— 29. The distal part of an opened ooecium of Mel. angulosa d'Orb. seen from tlic proximal end.
The whole atrial ring is seen. X 34.
— 30. Mel. pijrenaica d'Orb. A transverse section. X !!•
K. D. Vidensk. Selsk. Skr., 7 K., n-m Afd. VI, 9 [G. M. K. Levinsenj.
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VI, med 4 Tavler. 1890—92 13. 75.
1. Loreni, L. Lysbevaegelsen i og uden for en af plane Lysbelger belyat Kugle. 1890 2. •
2. Serensen, Wllllarii. Om Forbeninger i SveuimeblEBren, Pleura og Aortas ViEg og SammeDsmeltningen deraf
med Hvirvelsejlen sserlig hos Siluroiderne, samt de saakaldte Weberske Knoglers Morfologi. Med
3 Tavler. Resume en frangais. 1890 .^ 3. 80.
3. Warming, Eug. Lagoa Santa. Et Bidrag til den blologiske Plantegeografi. Med en FortegneUe over Lagoa
Santas Hvirveldyr. Med 43 Illustrationer 1 Te.\ten og 1 Tavle. Resume en franfais. 1892 10. 85.
VII, med 4 Tavler. 1890—94 13. 75.
1. Gram, J. P. Studler over nogle numeriske Funktioner. Resume en franjais. 1890 1. |o.
2. Prjtz, R. Methoder til korte Tiders, sarlig Rotationstiders, Udniaaling. En experimental Undersegelse.
Med 16 Figurer i Texten. 1890 1. 50.
3. Petersen, Emil. Om nogle Grnndstolfeis allotrope Tilstaiidsformer. 1891 t. 60.
4. ffarm|ng, Eug. Familieii Podostemaceae. 4<ie Afhandling. Med c. 185 mest af Forfatteren tegnede Figurer ■
I 34 Crupper. Resume et e.\plication des figures en franfais. 1891 1. 50.
5. Chrlstensen, Udin T, Rhodanchromammoniakforbindelser. (Bidrag til Chromammoniakforbindelsernes Kemi.
III.) 1891 1. 25
6. Lulken. Chr. Spolia Atlantica. Scopelini Musei Zoologicl Universitatis Hauniensis. Bidrag til Kundskab
om det aabne Havs Laxesild eller Scopeliner. Med 3 Tavler. Resume en franfais. 1892 3. 50.
7. Petersen, EmII. Om den elektrolytiske Dissociationsvarme af nogle Syrer. 1892 1. 25.
8. Petersen, 0. G. Bidrag til Scitamineernes Anatomi. Resume en franfais. 1893 2. 75.
9. Lutken, Chr. Andet Tiilaeg til "Bidrag til Kundskab om Arterne af Slaegten Ci/amus Latr. eller Hval-
lusene". Med 1 Tavle. Resume en franfais. 1893 85.
10. Petersen, Enill. Reaktionshastigheden ved Methylaetherdannelsen. 1894 1. 50.
Vm, med 3 Tavler. 1895—98 12. 25.
1. nieinert, F. Sideorganelne hos Searabae -Larverne. Les organes lateraux des larves des Scarabis. Med
3 Tavler. Resume el explication des planches en franfais. 1895 3. 30.
2. Petersen, EmII. Damptryksformindskelsen af Methylalkohol. 1896 1. •
3 Ituciiwaldt, F. En mathcmatisk Ondersogelse af, hvorvidt Vsdsker og deres Dampe kunne have en fslles
Tilstandsligning, baseret paa en kortfattet Frerastilling af Varmetheoriens llovedsxtninger. Resume
en franfais. 1896 2. 25.
4. Warming, Eug. Halofyt-Studier. 1897 3. .
5. Johannsen, W. Studier over Planternes periodiske Livsyttringer. I. Om antagonistiske Virksomheder i
Stofskiflet, sarlig under Modning og Hvile. 1897 3. 75.
6. Nielsen, N. Undersogelser over reciproke Potenssummer og deres Anvendelse paa Raekker og Integraler. 1898. 1 60.
IX, med 17 Tavler. 1898 — 1901 17. .
1. Steenstrup, Japetus, og Ltitken, Chr. Spolia Atlantica. Bidrag til Kundskab om Klump- eller Maanellskeue
I MoUdceJ. Med 4 Tavler og en Del Xylografler og Fotogravurer. 1898 4. 75.
2. Warming, Eug. Familien Podostemaceae. .i'^ Afhandling. Med 42 Figurgrupper. Resume en franfais. 1899 1. 60.
3. Meyer , Eirsllne. Om overensstemmende Tilstande hos Stofferne. En med Videnskabernes Selskabs Guld-
medaille belannet Prisafhandling. Med en Tavle. 1899 2. 60.
4. Jergensen, S. M. Om Zeise's Platosemiaethylen- og Cossa's Platosemiamminsalte. Med 1 Tavle. 1900 . . "75.
5. Chrlstensen, A. Om Overbromider af Chinaalkaloider. 1900 1. •
6. Steenstrup, Japetus. Heteroteuthis Gray, med BemiErkiiinger om Rossia-Sepiola-Familien i Almindellghed.
Med eji Tavle. 1900 . 90.
Gram, Bllle. Om Proteinkornene hos oliegivende Fre. Med 4 Tavler. Resume en franfais. 1901 .... 2. 50.
8. nieinert, Fr. Vandkalvelarverne (Larvce Dytiscidarum). Med 6 Tavler. Resume en franfais. 1901 . . 5. 35.
X, med 4 Tavler. 1899—1902 10. 50.
1. Jnel, C. Indledning i Lsren om de graflske Kurver. Resume en franfais. 1899 2. 80.
2. Bllluiann, EInar. Bidrag til de organiske Kvsegsolvforbindelsers Kemi. 1901 1. 80.
3. Samsee Lund og Rustrup, E. Marktidselcn (Cirsiuin arvense). En Monografl. Med 4 Tavler. Resume en
franfais. 1901 6. •
4. Chrlstensen, A. Om Bromderivater af Chinaalkaloiderne og om de gennem disse dannede brintfattlgere For-
bindelser. 1902 I. 40.
XX, med 10 Tavler og 1 Kort. 1901-03 ' 15. 05.
1. Warming, Eug. Familien Podoslemacea;. 6'° Afhandling. Med 47 Figurgrupper. Resume en franfais. 1901. 2. 15.
2. Ravn, J. P. J. Molluskenic i Uanmarks Kridlaflejringer. I. Lamellibranchiater. Med 1 Kort og I Tavler. 1902. 4. •
3. Wlnlher, Chr. Rotationsdispersioiien hos de spontant aktive Stoller. 1902 2. »
4. Ravn, J. P. J. MoUuskenie i Daiimarks Kridlaflejringer. II. Scaphopoder, Gastropoder og Cephalopoder.
Med 5 Tavler. 1902 3. 40.
5. WInther, Chr. Polarimelriske Undersegelser II: Rotationsdispersionen i Oplosninger *. 1. 60.
6. Ravn, J. I*. J. Molluskerne i Danmarks Kridtaflejringer. Hi. StratigraQske Undersogelser. Med 1 Tavle.
Resume en franfais. 1903 3. 85.
XII, med 3 Tavler og 1 Kort. 1902-04 10. 50.
1. Forth, Carl, Knudsen, Marliu, und Serensen, S. P. L. Berichle uber die Konstantenbestiramungen zur Auf-
stellung der hydrographischen Tabellen. Gesammelt von Martin Knudsen. 1902 4. 75.
2. Bergh, R. Gasteropoda opisthobranchiata. With three plates and a map. (The Danish expedition to Slam
1899-1900, I.I 1902 3. 45.
3. Petersen, C. G. Job., Jensen, Seren, Johansen, A. C, og Levinsen, J. Chr. L. De danske Farvandes Plankton i
Aarene 189S— 1001. 1903 ... 3. 25.
4. Chrlstensen, A. Om Chinaalkaloidernes Dibromadditionsproduktcr og om Forbindeiscr af Alkaloiderncs
Chlorhydralcr mod hiijere Metalchloridcr. 1904 I. 35.
Zoologiske Skrifter
udgivne af Det Kgl. Danske Videnskabernes Selskab
(udenfor Skrifternes 6te Raekke, se Omslagets S. 2—3) :
Kr. Ore
Bergh, R. Bldiag til en Monographl af Marseniaderne, m. 5 Tavler. 53 4. •
Anatomiske Bidrag til Kundskab om ^olidierne, m. 9 Tavler. 64 5. •
Esehrlcht, D. F. Anatomislt-physiologiske Undersegelser over Salperne, m. 6 Tavler. 41 2. 35.
Undersegelser over Hvaldyrene. Afhandling 1 — 6. m. 16 Tavler. 44—48 13. •
Om Gangesdelphinen, m. 3 Tavler. 51 2. >
Esehrlcht & Relnhardt. Om Nordhvalen, m. 6 Tavler. 61 4. 65.
Ni Tavler til Oplysning om Hvaldyrenes Bygning m. Forklaring. 69 2. 65 .
Hannover, A. lagttagelser over indkapslede Indvoldsorme hos Freen, m. 2 Tavler. 65 1. »
Om Bygningen og Udviklingen af Skjael og PIgge hos Bruskflsk, m. 4 Tavler. 67 2. >
Jungerspn, Bedor F, E. Ichthyotoniical contributions I. The structure of the genera Amphisile and Centriscus,
wilh 2 plales. 1908 2. 95.
Krabbe, H. Helminthologiske Undersegelser i Dannxark og paa Island, m. 7 Tavler. 65 2. 75.
Bidrag til Kundskab om Fuglenes Baendelorme, m. 10 Tavler. Resume en franf. 69 4. 80.
Krejer, B. Slagten Hippolytes" nordiske Arter, m. 6 Tavler. 42 3. 35.
LOtken, C. F. Additamenta ad hisloriam Ophiuridarum. 1 — 111, m. 7 Tavler. Resume en franf. 58—69 ... 6. 85.
Bidrag til Kundskab om Arterne af Slagten Cyamus Latr. eller Hvallusene. m. 4 Tavler. Resume en franf. 73. 2. 15.
Velhas-Flodens Fiske, et Bidrag til Brasiliens Ichthyologi, m. 5 Tavler. Synopsis Latina. 75 6. 75.
-^^^ Til Kundskab om to arktiske Slaegter af Dybhavs-Tudseflske: Himantolopbus og Ceratias, ra. 2 Tavler.
Resume en franf. 78 2. •
Spolia Atlantiea. Bidrag til Kundskab om Formforandringer hos Fiske under deres Vaext og Udvikling,
m. 5 Tavler. Resume en franf. 80 8. 20.
LjMge, Benn. Marine Lamellibranchiata, wilh 5 plates and a map. 1909 8. 60.
Melnert, Fr. Bidrag til de danske Myrers Naturhistorie, m. 3 Tavler. 60 2. 25.
Mortensen, Th. Echinoidea I., with 7 plates and a map. 1904 6. 85.
Prosch, V. Nogle nye Cephalopoder, m. 1 Tavle. 47 65.
RalhbuD, Mary J. Brachyura, with 2 plates and a map. 1910 3. 20.
Relnhardt, J. Beskrivelse af nogle nye Slangearter, m. 3 Tavler. 43 1. 50.
Mephitis Westermanni, ct nyt Stinkdyr fra Brasilien, ra 1 Tavle. 57 » 65.
Bidrag til Kundskab om Kjaempedovendyret Lestodon armatus. m. 3 Tavler. 75 2. 20.
Kaempedovendyr-Slaegten Coelodon, m. 5 Tavler. Resume en franf. 78 5. »
Beskrivelse af Hovedskallen af et Ksmpedoveudyr, Grypotherium darwinii, fra La Plata-Landenes pleisto- cene Dannelser, m. 2 Tavler. Resume en franf. 79 1. 75.
Reinbardl & Prosch. Om Scidaephorus Mulleri, m. 5 Tavler. 46 . 2. 25.
Scbjedte, J. C. Corotoca og Spirachtha, m. 2 Tavler. 54 1. 35.
Schinldl, Jobs. Ferskvandsaalenes languilla) Udbredning i Verden I., med 1 Kort. 1909'-. r 2. 25.
Stamiu, R. H. Om Musklernes Befaestelse til det ydre Skelet hos Leddyrene, med 2 Tavler. Resume en franc. 1904. 1. 95.
Steensirup, Jap. Rhizochilus antipalhum, m. 1 Tavle. 53 1. "
Hectocotyldannelsen hos Octopodslaegterne Argonauta og Tremoctopus, m. 2 Tavler. 56 I. 35.
Hemisepius, eii ny Slaegt af Sepia -Blzeksprutternes Familie, med Bemaerkninger om Sepia - Formerne i
Almindelighed, m. 2 Tavler. Resume en franf. 75 1. 25.
Spolia atlantiea. Kolossale Blaeksprutler fra det nordlige Atlanterhav, m. 4 Tavler. 98 2. 75.
Steenstrup & Liilkeii. Bidrag til Kundskab om det aabnc Havs Snyltekrebs og Lernxer, m. 15 Tavler. 61. . . 5. •
With, C.J. Chelonellii, with 4 plates and a map. 1906 7. 95.
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