632 TRANS. OF THE ACAD. OF SCIENCE. 
ings five, divided in the center, depressed below the poral 
pieces at the summit; four are irregular in form and small ; 
the fifth is about twice the diameter of the others and ovoid. 
Mouth central, stelliform. The side on which the largest ova- 
rian opening is situated is more full than the other sides ; this 
fullness renders the species unsymmetrical; the large open- 
ing is situated at the summit of the field, the second to the 
Size of Specimen (medium-sized adult ?).—Greatest — 
ivs inches; greatest diameter, 7°; greatest length oO io 
leces, 755 greatest length of first radials, j75 greate 
183: 
PENTREMITES ELEGANS, Nh. Sp. 
(Plate XX., Fig. 4a, 4b, 4c.) 
Body pyriform, greatest diameter a little below the age 
of the length of the body, diminishing very rapidly from 
* The term basal pieces is here used in a different sense from the same 
as used by authors in generic formula. 
