258 BULLETIN OF THE 



mens collected by Mr. Pourtales at Cape Fear. North Carolina, to have no 

 permanence. Liitken considers the Echinocidaris pustulosa Lam. as a 



nominal species ; quite a number of specimens of it were brought home 

 by the Thayer Expedition from Brazil. It may be that a larger series 

 than we possess will prove its identity with E. punctulata, but from the 

 material at hand I should consider it a good species, closely allied to E. 

 sequituberculata. I am inclined to think that the various West Coast 

 species of this genus will be limited to two, or at the utmost three, species ; 

 namely, E. stellata and E. nigra, perhaps E. spatuligera. 

 Littoral to 125 fathoms. 



Podocidaris sculpta A. A*;., nov. gen. et sp. 



This genus has the general facies of young Echinocidaris, with a de- 

 pressed abactinal surface as in Astropyga, the ambulacra rising in ridges 

 above the surface. The large spines are confined to the lower surface, the 

 primary tubercles scarcely extending beyond the ambitus. These tubercles 

 alone carry a large, smooth mamelon, while the rest of the test is covered 

 with rudimentary spines, arranged, however, in regular, vertical rows, four 

 of which form a distinct, raised band in the median interambulacral zone, 

 flanked by three more, less well defined, while in the narrow ambulacral 

 zone there are but two such rows, close to the poriferous zone, which is very 

 narrow, the pores being arranged in a single vertical row. The rudimen- 

 tary, knob-shaped spines, strongly serrate, are not carried upon a mam- 

 elon, but rise directly from the test, as in very young Sea-urchins, and are 

 connected at. their base by a ridge, leaving thus a more, or less quadrangular 

 pit in the space between four tubercles. This ridge is particularly promi- 

 nent between the spines of the median" interambulacral rows, while in the 

 more irregular rows the, ridges are less marked, forming simply depressions 

 in the test, running irregularly. The pits in the ambulacral zone are very 

 marked, and are connected into an irregular groove extending along the 

 whole ambulacral zone, the ridges, starting from the base of the tubercles, 

 extending only partway across the ambulacral area, like spurs and rounded 

 knobs. The whole surface of the test is covered with long-stemmed, articu- 

 lated pedicellarise, which have a distinct mamelon for their support, sur- 

 rounded by a sort of scrobicular circle, the base of the pedicellaria- forming 

 a ball-and-socket joint with the tubercle, while there is a thin muscular mem- 

 brane holding them in place, as in true spines, — an additional proof that 

 pedicellarise are only modified spines, as was made probable by their iden- 

 tical mode of development with spines, observed in the Star-fishes and 

 Spatangoids. The abactinal system, placed in a depression of the abacti- 

 nal part of the test, resembles that of Echinocidaris, having only four anal 



