Palceozoic Corals and Foraminifera. 5 



section, radiating lamellae meeting and complicated in the cen- 

 tre, connected by very thin transverse vesicular plates, and 

 the stars of the compound species separated by thick divisional 

 walls : budding in the compound species marginal, in the sim- 

 ple species often exhibiting periodical death and continuance 

 of growth from the centre, giving an imbricating " ringed " 

 appearance to the exterior. 



This genus is most allied to Cyatliophyllum and Clisiojihyllum, 

 all three having simply conic and compound polygonal-celled 

 species. Strephodes differs from Cyathophyllum by the equality of 

 the radiating lamellse and their meeting in the centre both in the 

 terminal cup and horizontal section, and in wanting the transverse 

 diaphragms ; from Clisiophyllum, which it resembles in the meet- 

 ing of the lamellae in the centre and the absence of horizontal 

 diaphragms, it differs in the centre (though often slightly pro- 

 jecting) not being elevated into the large tent-like cone, charac- 

 teristic of that genus, and in the rows of vesicular cells in the 

 vertical, section not having the reversed upward cm'vature which 

 is connected with that peculiar form of cell. The simple species 

 have been placed — I cannot imagine why — in the genus Strom- 

 bodes of Schweigger by Mr. Lonsdale and some others (see the 

 observations below on this latter genus). The compound species 

 differ from Astraa, with which many palaeontologists confound 

 them, by the solid boundary-walls to the cells (see note on this 

 genus below), and from Acervularia (Schweig., not Lonsd.) by 

 the marginal budding and want of the central tube of that 

 genus. 



The genus Streptoplasma of Hall in his recent volume on the 

 Palaeontology of New York, although defined nearly in the same 

 manner, and the name having the same meaning, applies ob- 

 viously according to his specific descriptions and figures of all the 

 species, not to the present corals, but to those known in Europe 

 under the names Petraia and Turbinolopsis, in which the lamellae 

 extend directly and simply almost to the centre, only the most 

 minute portion of the centre exhibiting in some species a trace 

 of twisting, and there being none of the vesicu^lar plates between 

 the lamellae which are so strongly developed in the present 

 group. 



Strephodes multilamellatum (IM'Coy). 



Sp. Char. Elongate-conic, very gradually tapering (generally 

 about 5 inches long, with a diameter of about li inch at the 

 termination) ; terminal cell oblique, oval, the short axis about 

 one-third less than the long ; surface regularly girt at about 

 every quarter of an inch with slightly oblique, strong cup- 



