630 TRANS. OF THE ACAD OF SCIENCE. 
pressed at the sutures marking their junction with the basal 
pieces, the second radials, and with each other, forming a 
nation of the pseudambulacral areas, sharply curving outwar 
at their junction with the margin of these areas; truncated 
of the interradial pieces ; marked by faint longitudinal strix 
which increase in size and distance from each other near the 
base of the interradial pieces, where they obliquely cross 
the pieces. Interradial pieces five, very long and large, lay- 
ing nearly on a plane with the poral pieces of the pseudam- 
-bulacral areas, sharply pointed at the line dividing the second 
radials to which they unite on either side by a double curved 
line. Pseudambulacral fields very long, being equal to six- 
sevenths of the vertical height of the specimen. The poral 
pieces composing the fields are quite thin, there being one 
hundred and one to each side of the line dividing the field, and 
two hundred and two to the whole field, which is one inch 
and one-tenth in length. The pieces are divided into four 
longitudinal bands to each field, those joining the central su- 
ture being considerably wider than those on the outer mar-_ 
gins of the fields. The margins of the fields are nearly par- 
allel to each other and about two-thirds their length, when 
they approach each other gradually by a curved line at the 
lower end of the field. The poral pieces are prominent, rising 
above the plane of the second radial pieces, and as high as 
their curved margins; disposed in the field at right angles 
with the vertical axis of the body, slightly curved, thus swell- 
ing the field on either side of the central suture, which 1s 
small and slightly depressed. Ovarian openings five, lee 
nearly equal in size, circular ; the largest one ovoid, and place: 
at the summit of the field ; the second on the left hand above 
the imperfect first radial* piece ; all the ovarian openings are 
divided centrally, the branches extending into the body vi 
either side of the interradiated pieces in a line pesmi y 
under the line dividing the poral pieces of the pseudambu * 
eral fields. Mouth central, at the summit, small, irregularly 
stelliform. Column very small, round, composed of pieces 0 
equal thickness. able 
All the main pieces composing the body are of remat . ‘al 
thickness and strength; the interradial and second ra 3 
pieces are fifteen-hundreths of an inch in thickness, in 2 me 
dium sized specimen. 
* 
Aan iin toeaiecn omnia 
* The relative position of the largest ovarian (?) opening in P 
mites differs in different species. 
