52 PROCEEDINGS OF THE JATIOXAL MUSEUM, vol.37. 



The larger blood vessels do not aj^pear to be so richly connected by 

 capillaries as in Edestus. Under high power a dense network of 

 bright lines, which are regarded as representing the dentinal tubes, 

 is to be seen, running irregular courses and branching dichotomously. 

 The shadowed areas seen around most of the capillaries are produced 

 by the network of dentinal tubes, slightly stained Avitli iron. 



3. DESCRIPTION OF NEW SPECIMENS OF LISSOPRION FERRIEUI. 



In 1907 " the writer described a fossil Avhich he regarded as re- 

 lated to Edestus^ but still more closely to Helicoprion. The type 

 specimen, now the property of the U. S. National Museum, Cat. 

 No. 6091, had been found in Upper Pennsylvanian dejiosits, near 

 Montpelier, Bear Lake County, Idaho, by Mr. AV. F. Ferrier. At 

 the time of publishing the description it was impossible to deter- 

 mine whether the complete structure would prove to be straight or 

 slightly bent, as the species of Edestus, or strongly bent, as the fossil 

 described b}?^ Dean as Edestus lecoxtci^ or spirally coiled, as Heli- 

 coprion hessonoici Karpinsky. Immediately after the appearance 

 of that description the writer received from Mr. Ferrier two ship- 

 ments of specimens from the same horizon at Thomas Fork, "Wyo- 

 ming, not far from the type locality. These showed that the series of 

 teeth and their shaft formed a spiral resembling closelv that of 

 Helieoprion. From the best of these specimens have been prepared 

 figs. 1 and 2, on pi. 14. At a later time, about October 1, 1907, Mr. 

 Ferrier made a fourth shipment, consisting of a block of lime- 

 stone, in which there was a complete example of this curious fossil 

 (pi. 15). Unfortunately the limestone is excessively hard and 

 tough, while the fossil teeth and their shaft are friable. As a result 

 the plane of cleavage has passed through the shaft and most of the 

 teeth instead of over their surfaces. Nevertheless the specimen dis- 

 plays well the coils of the spiral and the outlines of most of the 

 teeth. Taking all the specimens together, the most important facts 

 regarding the structure are made known. Credit is due Mr. Ferrier 

 for his interest in collecting so nnich material belonging to this 

 species. He has, moreover, presented to the IT. S. National Museum 

 the type of the species and important parts of the other specimens. 

 Mr. Ferrier is a geologist and paleontologist of much experience, 

 having been for some years assistant to Sir William Dawson, of 

 the Geological Survey of Canada, and being now engaged as mining 

 engineer in charge of phosphate mining for a commercial company. 



Besides the specimens of Lissoprion Mr. Ferrier has collected many 

 invertebrate fossils from the deposits that furnished Lissoprion^ and 



« Science, vol. 26, p. 22. 



