lusk: food economics 387 



Ophiomaria rugosa, sp. nov. 



In the largest specimen the disk is 16 mm. in diameter, and the arms 

 are about 50 mm. long. 



The disk is pentagonal with slightly concave sides, less stellate than 

 that of 0. tenella, thick, at the angles of the pentagon curving abruptly 

 downward to the arm bases. It is covered dorsally with fine granules 

 which become coarser toward the margin, where they tend to trans- 

 form into an irregular mosaic of small, very irregular, polygonal plates, 

 especially at the arm bases; the radial shields are covered. 



The granulation of the disk may cover uniformly all of the plates, 

 but usually one or more of the following series are visible; six widely 

 separated circular or oval primary plates, much swollen and elevated 

 above the general surface; a similar plate at each arm base, with some- 

 times a small one beyond it; between the plates at the arm bases a 

 similar but smaller plate, about the size of the central plate, in the mid- 

 interradial line; a small plate on either side of a line between each pe- 

 ripheral primary plate and the plate at the base of the corresponding 

 arm; a plate in the middle of each interbrachial border, as viewed dor- 

 sally, which sometimes forms the center of a series of very irregular 

 plates between the arm bases. 



The arms are essentially as in 0. tenella, but the side arm plates and 

 upper arm plates are rather strongly convex in profile, so that the arms 

 appear rugged. 



The plates in the interbrachial areas below are much smaller than 

 the corresponding plates in 0. tenella, and the granules are more abun- 

 dant, smaller, and more generally distributed. 



On the ventral surface there appear to be no essential differences 

 between this species and 0. tenella. 



Very young individuals with the radial shields exposed differ from 

 young specimens of 0. tenella in having smaller and more numerous 

 central plates on the dorsal surface of the disk, and swollen arm plates. 



Type.— Cat. No. 38579, U. S. N. M., from Albatross Station 2791, 

 off the coast of Chile, in 677 fathoms. 



PHYSIOLOGY. — Food economics. 1 Graham Lusk, Professor 

 of Physiology, Cornell University Medical College, New 

 York. 



The consideration of the food supply from a national stand- 

 point was forced upon Germany at the outbreak of the great 

 war which is now in progress. Eminent scientists combined 

 in a report upon the prospects of the sustenance of the nation. 



1 A lecture delivered before the Washington Academy of Sciences, April 14, 

 1916. 



