114 COELENTERATA—CNIDARIA CLASS II 
individual polyps. The proliferous zovids ure developed within urn-shaped capsules 
(gonothecae) of comparatively large size, and sometimes become separated off as 
free-swimming velate Medusae. 
Although existing Campanularians (Sertularidae, Plumularidae, Campanu- 
laridae) are provided with a durable periderm, their remains have not as yet 
been detected in the fossil state, with the exception of a few forms from the 
Pleistocene. Nevertheless, in the Upper Cambrian, Ordovician, Silurian, and 
occasionally in the Devonian, numerous 
a“ h 
ee finely branching plant-like remains are 
AOA ht found, which are sometimes furnished with 
ay Rye : \\ ce a strong foot-stalk, and sometimes terminate 
ae | af ( NESS acutely at the base; the original substance 
J aH W] KAS | of which was undoubtedly chitinous. These 
H Whi ~<a | forms are grouped together under the 
common term Cladophora, Hopkinson, and 
H) may be regarded as early types of the Cam- 
NOS HH NAH LKE, punulariace. — Particularly well - preserved 
S & \\ EBL YU, sR AE HET Esa uel Sie ane acre ae 
mene \ OL. k specimens exhibit on one o1 occasionally on 
mvp; Adley IA Le, Aki ~— both sides of the branchlets small cellules 
Pas \\ Wee EE or hydrothecae, which evidently served for 
Ve | Lig ea 6 the reception of zooids. Very often the 
A =e branches are united by numerous slender 
AUIS aay transverse processes or dissepiments. 
\ In the genera Dendrograptus, Callograptus, 
Fic, 201. Thamnograptus, and Inocaulis, Hall ; Calypto- 
cotiaDinenere, ernie graplus, Spencer ; Briagraptus, Lepwort 
b, Dictyonema, sp. Branch-bearing hydrothecae. €t¢., the organisms are provided with a 
From Drift of Northern Germany (after Dames). thick foot-stalk, by which they were prob- 
ably attached to some foreign object. The branches are numerous, slender, 
often bifurcating, bear hydrothecae, and are connected by transverse processes. 
Dietyonema, Hall (Dictyograptus, Hopkin.), (Fig. 201). Funnel- or fan-shaped 
branching fronds terminating acutely at the base, and probably unattached. 
Branches united at short intervals by dissepiments, and furnished distally on 
one side with hydrothecae; the latter, however, are rarely well preserved. 
Ordovician to Devonian. Particularly common in Ordovician rocks near 
Christiania, Norway, but usually compressed into fan-lke networks. 
Appendix to the Campanulariae. 
Graptolitoidea, Lapworth (2habdophora, Allman). 
Under the term Graptolitoidea or Graptolites are included organisms which 
are generally found accompanying the Cladophora in Palaeozoic strata, and 
1 Barrande, J., Graptolites de Bohéme. Prague, 1850.—Geinitz, H. B., Die Versteinerungen 
der Grauwackenformation in Sachsen. Leipsic, 1852.— Die Graptolithen des mineralogischen 
Museums in Dresden, 1890.—Hal/, J., Graptolites of the Quebec Group. Canadian Organic Remains, 
Decade II. (Geol. Sury. Canada), 1865.—Herrmann, O., Die Graptolithen-Familie Dichograptidae, 
1885.—Holm, G., Gotlands Graptoliter (Bihang Svenska Vetensk. Ak. Handl, vol. XVI.), 1890.— 
On Didymograptus, Tetragraptus, etc. (Geol. Foren. Stockholm Forhandl. XVII.), 1895.—Lapworth, 
(., Notes on the British Graptolites (Geol. Mag. vols. X. and XIII.), 1873-76. Also various papers 

