302 [December, 



229,) Prof. Hitchcock has given a notice, together with a wood cut, of a fossil 

 from the coal formation of Indiana, which bears a striking resemblance in form 

 to the fragment of Edestus vorax. The form of the teeth and their relative po- 

 sition to one another and the bone are the same in both fossils. The bone in 

 the wood cut is not represented as being segmented, but if it is so, and the 

 teeth are coosified with the segments, then the specimen actually indicates a 

 second species of Edestus. Prof. Hall informed me, that when he saw the original 

 of the fossil just noticed, that it appeared to him to be an ichthyodorulite. 



From the remarks of Prof. Agasaiz, appended to Prof. Hitchcock's notice, he 

 regards the latter specimen as " a part of the jaw of a shark allied to the saw 

 fish, or Pristis family." Not having seen the original specimen, I am unwilling 

 to consider it as belonging to a member of the peculiar family Edesiina, of which 

 Edestus vorax is the type, but if it does so, it will be widely separated from the 

 Pristis family, in which the teeth are inserted into imperfect sockets, and the 

 jaw exhibits no trace of segmentation. 



Remarks on Cylindr acanthus ornatus, Proc. A. N. S. viii. 12. The fossil frag- 

 ments of long, conical bones, which I supposed to be portions of the dorsal spine 

 of a fish, Prof. Agassiz informs me he considers to be the snout of a peculiar 

 genus of sword fishes, which he has incidentally mentioned in the Poissons 

 Fossiles, (t. V. p. 92,) under the name of Coelorhynclms. The correctness of 

 this view I do not hesitate to admit, and it appears to receive confirmation by 

 the inspection of a figure (plate xi. fig. 26) which I have since observed in 

 Dixon's Geology of Sussex, representing the snout with^its free extremity per- 

 fect. 



Remarks on Saurocephalus and its allies. This is the title of a paper recently 

 presented to the American Philosophical Society. The genus Saurocephalus was 

 founded by Dr. Harlan on a fragment of an upper maxillary bone with teeth, of 

 a peculiar genus of sphyrfenoid fishes, from the cretaceous formation of the 

 Upper Missouri. A second species, under the generic name of Saurodon was 

 subsequently described by Dr. Hays from a specimen consisting of the upper 

 and lower jaws, from the cretaceous formation of New Jersey. Prof. Agassiz 

 afterwards described the remains of several sphyraenoid fishes from the chalk of 

 England, which he has erroneously attributed to the genera Saurocephalus of 

 Harlan and Saurodon of Hays. Dixon, and other authors following Agassiz, 

 have described remains of fishes from the chalk of Europe, and have entirely 

 lost sight of the true Saurocephalus. The various remains attributed to the 

 latter appear to be separable into the following species. 



1. Saurocephalus lanciformis, Harlan : Jour. A. N. S. iii. 33'7 ; Med. and 

 Phys. Res. 362 ; Saurodon lanciformis Hays : Trans. Am. Phil. Soc. iii. 4'76. 



2. Saurocephalus Leanus, Harlan : Med. and Phys. Res. 362 ; Saurodon 

 Leanus, Hays : Tr. Am. Ph. Soc. iii. 4*77. 



3. PROTOSPHYRiENA perox, Leidy. Saurocephalus lanciformis, E.a,Tl&n, Agassiz: 

 Pois. Fos. V. 102, pi. 25c, figs. 2129; Dixon: Geol. Sussex 3'74,pl. xxx. fig. 21, 

 xxxi. fig. 12, xxxiv. fig. 11; Pictet : Traite d'Pal. pi. xxxii. fig. 7 ; Giebel : Odom. 

 pi. xliii. fig. 7, &c. 



4. Pkotosphye^na striata, Leidy. Saurocephalus striatus, Agassiz: Pois. Fos. 

 V. 102, pi. 25c. figs. 17 20 ; Dixon: Geol. Sussex 375, pi. xxxv. fig. 5. 



5. CiMOLicHTHTS lEVEsiENsis. Leidy. Saurodon Leanus, Hays, Agassiz : Pois. 

 Fos. V. 102, pi. 25c, figs. 30, 31 ; Dixon, Geol: Sussex 373, pi. xxx. figs. 28, 29; 

 xxxxiii.* fig. 10, &c. 



6. XiPHiAS DixoNi, Leidy. Saurocephalus lanciformis, Harlan. Dixon : Geol. 

 Sussex, in note to p. 375, pi. xxxii.* fig. 1. 



