312 A. E. Verrill — North American Ophiuroidea. 



In the more typical species the arras, though slender, are rather 

 short and not very flexible, but in some others they are long, slender 

 and very flexible.* 



Table of the species of A'mphipholis and Amphiodia from, the West 

 Indian region^ including Brazil^ and from the eastern coast of 

 North America. 



I. — Amphipholis Ljung. 



Three (rarely four) oral papilla ; outer one operculiform or 

 broad and flat, arising partly from the adoral shield. Radial shields 

 joined. 



A. — Disk covered with naked scales. 



a. — Three arm-spines, rarely four, on basal joints. 

 h. — Arms of moderate length. 



*^4. elegans (Leach) Ljng. Europe, America. 



A. tenera (Ltk.) Ljng, W. Indies. 



A, tenuispina Ljng. N. Atlantic. 



A. limhata (Grube) Ljng. Dorsal plates wide, short. Brazil. 

 A. suhtilis Ljng. Radial shields long and narrow. Brazil. 



hh. — Arms long and slender. 



A. Goesi Ljng. W. Indies. 



aa. — Four or five arm-spines. Arms very long and slender. Radial 

 shields long and narrow. Oral shields large, obovate. 

 Adorals narrow. Outer oral papillae very broad. 



A. gracillima (Stimp.) Ljng. S. Carolina. 



AA. — Disk-scales with small, scattered spinules. Two small tentacle- 

 scales. Radial shields in contact for half their length. Three 

 arm-spines. 



A. ahnormis (Lym. '78, as Ophiocnida). W. Indies. 



* Among foreign species of this genus are the following : A. squamata, 

 Europe ; A. Torelli, Iceland ; ^4. Pugctana, A. violacea, A. microdiscus, A. Pun- 

 tarence, A. geminata, the last five from the west coast of America; A. Pafagonica, 

 Magellan Str. ; A. Kochii (Lym.) and A. Corece (Duncan), East Asia. The follow- 

 ing have four oral papillae; A. impressa Lj., E. Indies; A. depressa Lj. and 

 A. hastata Lj., from S. Africa. 



