4 PEOCEEDINGS OF THE XATIOXAL MUSEUM. vol. 66 



fiecl in describing it shaped like Clypeaster. The test, howeverj 

 clearly was broad and flat as in ScuteJlu. and such of the plates of 

 of the upper (abactinal) surface as can be made out do have a 

 scutelliform arrangement. A hypothetical restoration of the abac- 

 tinal surface, based on the specimen in hand and a Miocene SciiteJla^ 

 is shown in figure 1. 



The petaloid areas and the central part of the test have been 

 deeply excavated at some time and now disclose a group of peculiarly 

 shaped plates which, however, may be matched closely with those 

 of the undersurface of Scutella. A diagram comparing the arrange- 

 ment of the plates with that of a Miocene ScutcUa is given in fig- 

 ure 2. 



It seems to the writer probable that if better material is ever 

 discovered this genus will be found very close to ScuteUa. if not 

 identical with it. Inasmuch as only the single unsatisfactory speci- 

 men is now at hand, it seems best for the time being to leave the 

 generic assignment as it was made by Cragin. The known Scutel- 

 lidae are all Tertiary, and the present species if interpreted cor- 

 rectly would extend the range of the family into the Upper Cre- 

 taceous. 



EXPLANATION OF PLATE 



Plate 1 

 Sctitellaster cretaceus Cragin 



Fig. 1. Tjrpe specimen, natural size. Photographs, retouched. 



2. Area indicated by small rectangle on figure 1, enlarged 5 diamettTS^. 

 Photogi'aph, retouched. 



o 



