I'i nti 56 



Fig. 1. Astrometis sertvlifera, No. 38533, U.S.N.M., Santa Margharita Island, L. C. Skeleton of 

 ray nearthe base (first plate on left is the ninth) showing the carina] plates (fi), dorso- 

 laterals (DL), superomarginals {Si. and inferomarginals (7). The lighter areas on the 

 superomarginals indicate the area of pebbling. Base of ray to left, <5. la. Same 

 specimen. Second to fifth supero- and inferomarginal plates, base of raj to left, X5. 

 lb. Same specimen. Actinal view of 3 inferomarginal plates and corresponding 

 actinal (A) and adambulacral plates {AD near base of ray, X10, X, skeletal interval 

 lr. Same; Tepoca Bay, Gulf of California. Mouth plates and proximal adambula- 

 cral and ambulacra! plates, >,s. \,i. Same specimen. Tip of subora! -pine, showing 

 groove, X15. If. Same specimen from Half Moon Bay (?), California. Mouth plates, 

 and associated adambulacral and ambulacra! plate-. 8. The adambulacral plates 



have been cleaned. The larger actinosl ial -pine is Hatter than in the l< ; 8. If. 



Same specimen. Another actinostomial month spine. 



2. Sclt rn si i riasheti ropat s, type. A -mall portion of the specialized pebbled area of the supero- 



marginal plates, enlarged X 100. The surface of the plate is viewed somewhat in per- 

 spective. 



3. Astrometis sertulifera, La Jolla, Calif., X 10. Portion of actinostomial ring from coelomic 



side; mouth plates dotted. 3a. Same. Side view of crest of firsl ambulacra! (.A) and 

 mouth plate- 1/ after removal of odontophore. 



217 



