112 SYSTEMATIC PALEOXTOLOGY 



form extant. The Tertiary caudal fans which have been theoretically 

 associated with the teeth of Ischyrhiza by Cope and Clark are here con- 

 sidered to belong to typical Sword-fishes. The following species is the 

 only one known to occur in Maryland. 



XiPHiAS (?) KADiATA (Clark). 

 Plate XII, Fig. 8. 



Ischyrhiza (?) radiata Clark, 189.5, Johns Hopkins Univ. Circ, vol. xv, p. 4. 

 Ischyrhiza (?) radiata Clark, 1896, Bull. 141, U. S. Geol. Survey, p. 60, pi. vii, fig. 

 2a (? non tigs. 26, 2c). 



Description. — Terminal vertebral centrum deeply concave in front and 

 circular in cross-section, its neural and haemal spines fused into a solid 

 fan-shaped body; the anterior haemal spine less completely fused with 

 the next following than are all the rest, and even separated from it near 

 the point of attachment with the centrum by a small perforation passing 

 completely through the fan. [Dentition and other parts of the skeleton 

 unknown.] 



This species is established on a unique fan-shaped body, the extreme 

 height of which is 3.9 cm.; but some of the South Carolina specimens 

 exceed 10 cm. The latter also differ from the Maryland form in having 

 the vertebral centrum transversely elongated instead of circular. 



The type is a hypural fan in the Museum of Johns Hopkins Uni- 

 versity. 



Occurrence. — Aqitia Formation". Clifton Beach. 



Collection. — Johns Hopkins University. 



Genus PHYLLODUS Agassiz. 

 The presence of this interesting genus in North America was first 

 made known by Dr. Jeffries AA^yman,^ who came into possession of two 

 unique dental plates from the Eocene of Richmond, Virginia. Rather 

 poorly executed Avoodcuts of both specimens are given by him, the more 

 perfect one being compared with P. toliapicus Agassiz, and the other 

 declared to be different from any described species. This paper of AVy- 

 man's seems to have escaped general notice, and was certainly over- 

 looked by Marsh,' when in 1870 he chiiiiied lii;^ P. clcgans and P. curvi- 



1 Ainer. Jour. Sci., ser. ii, vol. x, 1850, p. 2:^4. 



'''Proc. Anier. Assoc. Adv. Sci., 18tb Meet., 1870, p. 228. 



