KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 32. N:0 I. 101 



The fig. 5, pl. 51, L. puella, represents clearly a Plasmopora, possibly Pl. foUis, and Fl. 

 discoidea, pl. 4, f. 3 seems also to belong to that genus. 



This genus Cainptolithus is to be characterized as follows. The calicles are filled 

 with a coenenchyinatoid mäss of convex lamella? instead of tabulaj, and when these liave 

 sometimes been developed, they fonn a inuch curved, convex arch. The septa are little 

 developed and the coenenchyma consists almost entirely of convex lamella; Avith scattered 

 aculee. At present only one species is known, from the Upper Silurian of the Niagara 

 group in North America. 



Camptolithus papillatus. Rominger. 



Pl. X, figs. 25—30. 



1876. Lyellia papillata ROMINGER. Geol. Survey Michigan, vol. III, pt. 2, p. 16, pl. II, fig. 3. 



1878. » ■!> QUENSTEDT. Petref. Deutschl., p. 150, pl. 149, tigs. 7—8. 



1885. » 2 Davis. Kentucky Foss. Corals, pl. 2, f. 2(?), pl. 3, f. 1, pl. 4, f. 4 (bad specimeu). 



Through decay, being weathered, and through silicification it has been much deformed 

 and shows an exteriör similarity with L. americana in having the tubes of the calicles 

 partially standing free and laterally connected by horizontal shreds of coenenchyma, that 

 hava withstood destruction. The transverse section shows large calicles (2,5 millimeters) 

 provided with twelve short septa, the theca angular or indented in face of thera. Through 

 changes during the process of fossilization the septa have assumed quaint shapes, they are 

 cuspidate with hooks or barbs on the sides and in their apex (pl. x, fig. 25) and there 

 are small accessory, septalike spines. The centre of the tabulte is dotted with a great 

 number of small spines, figs. 25, 27, which possibly may be of organic origin. The 

 calicle, instead of having regular horizontal tabulse, is filled \vith convex tabulae, fig. 30, 

 elevated as an arch in their centre and often so crowded that they interfere with 

 their regular growth and consequently there arises a tissue of smaller convex tabulaj giving 

 the whole an appearance quite similar to the ambient coenenchyma, figs. 28 — 29. By 

 this the perfect homology of tabulas and the coenenchymal disscpiments is clearly de- 

 monstrated. The coenenchyma is composed of nearly equal-sized lamella?, having sometimes 

 a tendency to be arranged in longitudinal rows (pl. x, f. 30) without being separated 

 through bacilli. Of such there are some (f. 29) in another specimen even in the calicle, 

 but aculfe are dispersed everywhere on the lamellaj. As seen in fig. 26 there are vestiges 

 of costal radii emanating from the theca and the photographic tigures of Rominger and 

 Davis exhibit also such radii. The calicles are much distorted and defaced by låter 

 changes. 



The Swedish State Museum is in possession of specimens from Point Detour, Lake 

 Huron, Michigan, the only place from which it has been obtained. The specimens were 

 given by Dr Rominger. 



K. St. Vet. Akad. Handl. Baad 32. N:o 1. 13 



