1W1 



OOXIATiTES. 



OONIAT1TK-!. 



1071 



variations of the suture*. The arrow is in each case supposed to point 

 towardt the aperture. 



Division 1. The dona] lobe simple ; one lateral lobe. 



a. Lateral lobe single and rounded. G. espantiu, Von Bucli, 



fg.6. 

 i. Lateral lobe tingle and angular. G. mUirrii, Minister, Jig. 7. 



Division 2. The dorul lobe simple ; more than one lateral lobe. 



a. Lateral lobaa linguiform, and nearly equal G. llemlovi, 



Sowerby, .ty. 8. 

 4. Lateral lobes rounded and nearly equal. G. terpentiniu, 



Phillip*, jf 9 . 9. 

 r. Inner lateral lobes very much the largest. G. Mttnitrri, Von 



Buch, fg. 10. 

 d. Lateral lobe* very unequal and oblique. G. Ifirninghautl, 



Von Bm-h, >;/. 11. 



Division 3. Donal lobe divided ; lateral lobe single. 



a. Lateral lobes and sinuses rounded, ii. bidortalU, Phillips, 



fig-ll 

 i. Lateral lobes and sinuses angular. G. atrialtu, Sowerby, 



fg. 13. 



Division 4. Donal lobe divided or complicated ; lateral lobes more 



thsn one. 

 O. eyclolobui, Phillips,/?. 14. 



- 



- 



The same transition rocks which contnin a large portion of the 

 "'iitincntal specie* of Goniatites yield a cognate group, from which 

 they are with difficulty distinguished. There were first separat. .1 l.y 

 ( (,unt Munstrr, under the name of Clymrnia. It GoniatiU-s are consi- 



dered as of the ammonoid, Clymenur may be included in the uautiloid 

 type. Their siphon is always ou Uie inner margin, and the sepU, 

 instead of a reflex wave on the dorsal Hue. h:in- tin r,- :i IK-IK! forward 

 toward the aperture. The Clyiuruiir have all the same variation* of 

 form and surface which have been ineiitionod with regard to (ioiii.i- 

 tites. Figt. 15 to 18 represent the forms of septa of Clymenitr, for 

 comparison with those of Gouiatitcs. 



Fit. 1*. 



Clymruia romprrua. (Mdniter.) 

 Tig. 17. 



i'lymrnia tliala. (MUnetcr.) 



Compared with ordinary Ammonites, the differences of the sutures 

 are easily seized ; but by the group of Ceralilei of ll.ian, which is 

 supposed to be peculiar to the niuschrlkalk, the transition is not 

 difficult, as the Bubjoined figures show. 



Fin. 19. 



Auimmiitri planicoitatus. (Sowerby.) 

 Fig. 20. 



Ciraritfi nodoivt, vnr. 



Goniali/tt, and their nllie*, the Clymmitr, appear entirely confined 

 to the rocks of the carboniferous and older systems of strata. Only 

 one species ((loniatiltt Liftrri, Sowerby) is mentioned as occurring in 

 the coal-formation, and that in the lowest portion (near Bradford, 

 Halifax, and Sheffield, Yorkshire). 



In the strata presumed to lie below the old red-sandstone occur 

 many other species ; at leant H> in the fact on the continent of Europe, 

 though in Great Britain and Ireland they are but rarely met with in 

 the primary and transition strata. 



The Ooniatites yet described arc almost entirely from European 

 1 -call tie*. Von Dechen quotes <1. Liittri from India. (' Hiuidl'ucli 

 der Geognosie.') None are mentioned in the slaty rocks of \\ . t 

 moreland or Wales ; none occur in tin- Silurian Hocks: they are not 

 rare in Devonshire (occurring about Banistaple and near Launceston). 

 It is in the North of England, from Derbyshire to the Tweed, and 

 in the limestones of the carboniferous system of strata, that iln-y 

 specially abound. About Kuuixkilli n, and near Castleton, in the Isle 

 of Man, the same rocks yield a considerable number of species. 



The following is a list'of the British species as given in Tennont's 

 ' British Fossils,' 1847 : 



CARBOBIFEROUS GRODF. 

 t'i'oniatitri Udonalii, Phil. G. carina, Phil. 



(/. lifena, Phil. 

 <j. Jlrotmii. 

 G. calyx, Phil. 



G. creninria, Phil. 

 (,'. ../.-tolobm, Phil. 

 G. rfuciw. 



