( 298 ) 
paper. « À new parasitic mollusk of the genus Eu- 
lima (1). » 
Ptilocrinus antarcticus sp. n. 
Diagnosis. — À Ptilocrinus with height of BB less 
than half that of RR, and about half diameter of cup at 
basiradial suture. Proximal border of basal cup projects 
beyond column to à distance equal to about one-sixth 
diameter of proximal columnals. RR about as wide as 
high, with broad median longitudinal ridge, less wide 
than arms, and tending to bifurcate at basal end. Facet 
about five-eighths width of R, facing outwards markedly. 
Interbrachials verrucose, continuous with similar but 
smaller interambulacrals to form a domed tegmen equal 
in height to the cup. Brachials somewhat swollen, so 
that arms have à nodose outline. Pinnulars with ridged 
sides. Proximal columnars varying in diameter and 
height according to orders of growth; the larger ones 
tuberculate. 
Holotype, specimen B (fig. 1). 
The coarser ornament, more pronounced ridges, and 
slightly more massive appearance of this species may be 
connected with the fact that it was dredged from a 
depth only one-sixth of that at which P. pinnatus was 
found. 
(4) Proc. U. S. Nat. Mus., n° 1548, vol. XXXII, pp. 555, 556, pl. li, 
5 June 1907. 
