Reviewed hy Dr. Christian Lutken, 377 



ever, the fish was principally known from Beyrich's description, 

 and was commonly held to be a shark related to the recent Squatina. 



In 1861 Dr. Geinitz gave a new description and a beautiful figure 

 of it (natural size), in his excellent work on the " Dyas" (pp. 22, 

 23, f. 1). The discovery, that a remarkable disc-like body, often 

 accompanying the fossil fish, was formed of the coalesced ventral 

 fins, transformed into a sort of sucking-disc, induced this author to 

 place it (with Keichenbach) in the vicinity of the Discoboli (Cyclop- 

 terines), rather than in that of the Placoidei. 



Our author then proceeds to describe in detail the various specimens 

 entrusted to his examination by the Museums of Dresden, Berlin, 

 Breslau, and Vienna, and some private gentlemen (Dr. Weiss and 

 Dr Jordan) at Saarbruck, forming together a much richer series of 

 specimens for the investigation of this curious Permian genus, than 

 any of its previous observers had before them. This descriptive por- 

 tion of Professor Kner's memoir is accompanied by ten lithographic 

 plates. It is hardly possible to give an abstract of it, nor is it neces- 

 sary, as we may learn from the general sketch given below, of the 

 whole organisation of the animal, in which the author has himself 

 condensed all the most essential results of the preceding elaborate 

 description. If I add that it is no easy task to follow the author 

 through his detailed account of all the more or less fragmentary and 

 often indistinct and dubious specimens, and that the figures do not 

 always aid the understanding of the text, so well as might have been 

 expected, this is not intended as a reproof; I fully understand how 

 very difficult their interpretation and figuring in many instances 

 must have been. 



'' The general form of the body was elongated, the head broad, 

 rather depressed, the snout broadly rounded, the mandible some- 

 what prominent, the mouth closely beset with rows of pointed teeth 

 on the inter-, supra-, and infra-maxillaries, the palatine and pharyngeal 

 bones. Most of the teeth were three-pointed, with a short median 

 point and two longer diverging lateral ones that arose from the 

 posterior border of the base, and during repose were laid down in 

 such a manner that only this basilar portion stood forward. They 

 were hollow from the base towards the points, and therefore easily 

 broken ; some had a smooth, others a furrowed surface. In the 

 lateral parts of the jaws they were arranged in 28-29 rows of 6-8 in 

 each transversely ; on the inter-maxillary they formed 4 rows of 

 6-8 in each. Beside the tricuspidate teeth, there were perhaps 

 some with one point only, — we suspect that on the pharyngeal 

 bones there were also others with two and four points, or even five 

 and six ! The osseous palatine arch appears to have formed, as in 

 sharks, a simple maxillary suspensorium connected with the mandi- 

 ble. The existence and position of the eyes cannot be fully stated, 

 but it is certain that four or five branchial arches were present, 

 armed with a few long rake-shaped teeth : and in the front of these 

 arches numerous thin branchiostegal rays were attached to the distal 

 end of two large bones, answering to the cornua hyoidea. The 

 connexion between the branchial apparatus and the shoulder- 



VOL. V. — NO. L. 25 



