172 Reviews — Prof. Q. Linddrbm on Prisciturben. 



admits that mammoth's teeth and remains of other animals, con- 

 temporaries of man, have sometimes been found over and sometimes 

 under Boulder-clay. This fact, no doubt, needs explanation, and 

 can (he believes) be completely explained by an entirely different 

 cause (as he proposes to show elsewhere). It certainly does not (in 

 his opinion) support the theory of interglacial warm climates. 



REVIEWS. 



I. — TJber die Gattung Prisciturben, Kunth. Von G. Lindstrom. 

 Bihang till k. Svenska Vet.-Akad. Handlingar, Band 15, Afd. iv. 

 No. 9 '(1889), pp. 1-11, Taf. i., ii. 



On the Genus Prisciturben, Kunth. By Professor G. Lind- 

 strom, of Stockholm. 



THE type forms of the genus Prisciturben, described_by Kunth l 

 as a Perforate Coral from the Silurian strata of Oland, have 

 been unfortunately lost, and, owing to the death of this author, 

 nothing but the description and figures remain by which the genus 

 can be identified. Prof. Lindstrom thinks that the original speci- 

 mens must have been derived from Gotland instead of Oland ; for 

 whilst nothing at all corresponding to the genus has been recognized 

 from this island, there have been found in Gotland forms which 

 agree in so many respects with Kunth's descriptions that there can 

 be no doubt that they belong to the genus. The specimens in 

 question are thin laminate expansions, with a concentrically rugose 

 epitheca on the lower surface, and on the upper numerous small 

 calices are irregularly grouped. The interspaces between the calices 

 — described by Kunth as the ccenenchyma — are papillate and covered 

 with delicate open channels radiating from various centres, and in 

 this substance the calices are usually so immersed that their lateral 

 walls are entirely concealed. The calices occur in all stages of 

 growth; in the smallest, hardly 1mm. in diameter, there is but 

 a single septum developed on the lower side of the oblique calices ; 

 at a slightly older stage there are two additional septa, one on each 

 side of the primary ; these are followed by yet other two, similarly 

 situated, and then a single- septum appears on the upper side of 

 the calice directly opposite the primary. In full-sized calices, which 

 are not more than 4 mm. in diameter, there are from 30 to 36 septa, 

 alternately large and small, and their outer margins are considerably 

 thickened. The walls of the calices are faintly ribbed and sharply 

 marked off from the ccenenchyma in which they are imbedded. The 

 development of the septa in this Coral follows precisely the same 

 course as that which Prof. Lindstrom has already noticed in many 

 other Rugose Corals, as in Goniopliyllum, Cyathophyllum mitratum, 

 Diphyphyllum, sp., etc., but, curiously enough, this inequal develop- 

 ment appears only to occur in species which in their earliest stages 

 of growth are vermiform or tubular in shape, and attached by one 

 side, whilst in species which are free and have a direct vertical 



1 Zeitschr. d. deutsch. Geol. Gesells. 1870, pp. 82—87, pi. 1, figs. 2a— 2b. 



