DESCRIPTION OF NEW SPECIES. 



OPHIOMAZA.* Gen. nov. 



Tooth. Tooth-papillae numerous, and arranged in a close vortical 

 oval, as in Ophiothrix. No mouth-papillae. Disk below naked, but 

 covered above with large, swollen radial-shields and plates. Arm- 

 spines stout, nearly smooth, as in OpMocoma. 



This curious genu- has the dentition of Ophiothrix, the disk of Ophio- 

 cnemis, and the arms of Ophiocoma. 



Ophiomaza cacaotica. Sp. nov. 



Plate I., fig. 15. 



- ial Marks. — Five, sometimes six arm-spines, the two or three 

 upper ones considerably largest. No tentacle-scale. Interbrachial 

 plates on back of disk elongated and irregularly broken. 



Description of a Specimen. — Diameter of disk. ll mm ; from outer side 

 of mouth-shield to outer comer of opposite mouth-slit. 4. •J" 1 " 1 : distance 

 from outer side of mouth-shield to inner points of tooth-papillae, com- 

 pared to that between outer corners of mouth-slits, 2.5 : 2. Width of 

 arm. 2 mm - ; length of arm about 30 mn ; tooth-papillae small and crowded, 

 about 26 to each angle of the mouth ; four strong, square-edged teeth. 

 Under arm-plates, beyond edge of disk, broader than long: their lat- 

 erals and inner side slightly re-enteringly curved : outer side slightly 

 curved: length to breadth (6th plate). 9 : 1.2. Within the disk there 

 are six plates, of winch the one next the mouth-slit is small and oval : 

 those outside of it grow gradually broader and are shaped like those 

 beyond the disk: side arm-plates stout, but not much projecting; upper 

 arm-plates broader than long, somewhat irregular, broader without 

 than within, outer side curved ; length to breadth (8th plate). .9 : 1.6. 

 The first two or three plates are narrow and wedge-shaped and fit in a 

 notch in the disk ; beyond the margin they grow wider, and have their 



* "0<f>is. serpent ; pif«. a cake. 



