THYRSION 17 



longer than deep, somewhat constricted, the first neural spines of the 

 dorsal attached to the first vertebra. Eleven vertebrae preserved. 



No. 6. Broken fish 14 inches long. Vertebrae 13 -f- 25 = 28, 

 longer than deep, smaller anteriorly, more or less three-grooved, part 

 of them nearly plain. Head much broken, 3% in length to base of 

 caudal ; depth about S 1 ^ in length ; preopercle with fine striae on exserted 

 part; pectorals much broken; ventrals just behind their insertion; first 

 dorsal with 8 spines preserved, slender, close-set; soft dorsal well sep- 

 arated, small, of about 12 feeble rays preserved. The interneurals of 

 both dorsals very short and slender, a little shorter than the slender inter- 

 haemals. Caudal broken, forked. Same slab with a small sample of 

 XYNE GREX. 



No. 180. Fragments of a large fish, apparently TURIO, in bad con- 

 dition. 



10B. Backbone with anal fin, 7 1 /^ inches long. 



The species is named for Dr. Ray Lyman Wilbur, President of 

 Stanford University. 



Thyrsion Jordan, new genus. 

 (Type THYRSION VELOX Jordan.) 



This genus is characterized by the general form of the Spanish 

 mackerels, the depth about five times in length to base of caudal, the 

 vertebrae strong, 40 in number. The interspinal bones weak, the spinous 

 dorsal of 10 to 20 weak spines, and the teeth conical, in bands. The 

 number of dorsal spines cannot be ascertained. 



6. Thyrsion velox Jordan. 

 (Plates VIII, IX) 



The type of the species (No. 153) shows the head and anterior part 

 of the body. The whple part preserved, 9 inches long. Head large, 

 with long pike-like jaws, its length half more than presumable depth of 

 body at front of first dorsal. Depth of head about 1% in its length; jaws 

 very long, apparently pointed, the tips broken, the maxillary 1% in head. 

 Teeth in upper jaw sharp, entire, even, close-set, rather narrowly triangu- 

 lar or possibly conical in form, 50 or 60 on each side in upper jaw, none 

 of them canine-like, and perhaps all in one row ; more likely in bands. 

 Anterior teeth narrowed and crowded; lower jaw strong, its teeth partly 

 preserved, similar to those above, opercle large, rounded. 



Fourteen vertebrae preserved, these rather small and squarish; 10 in 

 the length of upper jaw; the neural spines slender, directed rather evenly 

 backward ; haemal spines smaller. First dorsal with but three slender, 



