28 PANAMIC DEEP SEA ECHINI. 



varying greatly in outline and even in its general trend, being often 

 irregularly pentagonal. The madreporic body is prominent in early stages 

 and is usually placed towards the anterior edge of its genital plate. In 

 all the specimens examined the primary anal plates retain their predomi- 

 nance and can readily be traced. 



The great thickness of the genital and ocular [dates is well seen in 

 PI. 8, fig. 6, which shows the abactinal system from the interior of the test- 

 It will be seen that the right posterior genital plate is divided into two 

 plates, and that the madreporic genital plate also shows a suture half-way 

 across the plate. The uniform and close granulation of the abactinal system 

 of P. Milleri recalls that of the typical cretaceous Stereocidaris. The whole 

 abactinal system is covered with secondaries of nearly uniform size (PI. 7. 

 figs. 1-5), with but few miliaries in the central part of the genitals. An 

 enlarged view of these is shown on the ocular plate of the odd ambulacrum 

 (PI. 8, fig. .',) ; this also shows the young poriferous plate forming between 

 the ocular plate and the uppermost ambulacral plate. Plate 8, fig. 1, shows 

 the same seen from the interior of the test. PI. 8, figs. ,' and 3, show 

 from the interior the ocular plates and adjoining ambulacral plates of 

 the right anterior and the left posterior ambulacra. 



Station 3359, off Cape Mala, 465 fathoms. Lat. 6 22' 20" N. ; Long. 

 81 52' W. Bottom temperature 42°. Rocky. 



Station 3360, off Cape Mala, 1672 fathoms. Lat. 6 17' N. ; Long. 82 

 5' W. Bottom temperature 36°. 4. Fine blk. drk. gr. S. 



Station, 3381 off Malpelo Isd., 1772 fathoms. Lat. 4 56' N.; Long. 80 

 52' 30" W. Bottom temperature 35 .8. Gn. M. 



Station, 3399 off Galera Point, 1740 fathoms. Lat. 1 7' N. ; Long. 

 81 4' W. Bottom temperature 36 . Gn. ooze. 



Station, 3415 off Acapulco, 1879 fathoms. Lat. 14 46' N. ; Long. 

 98° 40' W. Bottom temperature 36'. Bn. M. Glob. Ooze. 



Bathymetrical range, 465-1879 fathoms. Range in temperature. 

 42-35.8. 



