CHAP. V.) THE GULF-STREAM. 371 
Only one specimen occurred of a species of Amphiura which 
has not yet been determined; but there were seven or eight 
examples of the handsome Ophioglypha figured in wood - cuts 
104 and 105. Ophioglypha bullata belongs to the small sub- 
section of the genus, with short, knotted arms, slit -like foot- 
pores, and marked grooves between the joints of the arms; 
which already contains two arctic species, 0. nodosa and O. Stu- 
witzii ; it is most nearly allied to the former of these, but there 
are many points of distinction. 
The diameter of the disk in a full-grown specimen is 10 mm., 
and the length of the arm is about twice and a half the diame- 
ter of the disk. The dorsal surface of the disk is covered with 
rather prominent granular scales of different forms and sizes; 
six of the larger of these form a rosette in the centre of the 
disk, but they are separated from one another by bands of the 
scaly perisom, and not in contact as in O. nodosa. The radial 
shields are prominent, slightly longer than broad, and they also 
are separated throughout their entire length by wedges of peri- 
som. The mouth-shields are egg-shaped, very large and prom- 
inent, occupying nearly the whole space between the arms, and 
running out quite to the edge of the disk. These inflated 
mouth-shields give a very marked character to the species. The 
mouth-papillee are short and blunt, about twelve on each angle 
of the mouth; the teeth are six or eight in number on each an- 
gle, and rather long and pointed. The under arm- plates are 
square and prominent, apposed to one another in series near the 
bases of the arms, but rapidly separating and becoming smaller 
and rounder distally. The upper arm-plates are small and like- 
wise prominent. The lateral arm-plates are large and rounded, 
and project laterally, which gives its peculiar knotted or beaded 
appearance to the arm. The arm-spines are very small, in a 
row of five or six on each lateral plate; on the distal arm-joints 
they become somewhat longer. The large elliptical foot-pores 
are fringed all round with closely set flat papille. Ophioglypha 
