234 BULLETIN OF THE 
Sigsbeia murrhina sp. nov. 
Plate III. Figs. 55-58. 
Special Marks. — Arms stout, and in length about six and a half times the 
diameter of the disk, Plates of body and arms thick, and often swollen and 
tuberculated. One tentacle-scale. Two arm-spines, 
Description of an Individual, — Diameter of disk 12 mm. Length of arm 
about 80mm, Width of arm close to disk 5 mm. Nine to eleven irregular 
crowded mouth-papille to each angle, the outer one on either side largest and 
resting on side mouth-shield, the innermost one at the apex of jaw, large, 
spearhead-shaped. Four or five stout, flat, blunt teeth, similar to the inner 
mouth-papilla. Mouth-shield broader than long, with an obtuse peak within 
and a blunt prolonged angle without ; length to breadth 1.4 : 1.7. Side mouth- 
shields squarish, about as wide as long, meeting broadly within and having 
their lateral sides rounded. First under arm-plate much wider than long and 
much shorter than its successors : the next three or four are somewhat wider 
than long, slightly swollen, with inner edge straight; outer edge wider than 
inner and nearly straight, and lateral sides re-enteringly curved. Side arm- 
plates high, narrow, and swollen ; above, they wedge in between the upper 
plates, and are shorter there and below than at their middle point. Upper arm- 
plates transverse-oval, much swollen, and covering only a part of the upper 
surface. The supplementary piece on either side of the upper arm-plate is 
large, swollen, tuberculated, larger than the side arm-plate, and extending 
downward to the arm-spines. At the tip of the arm it first appears as a granule 
somewhat smaller than an arm-spine ; and it gradually increases in size to the 
base of the arm. Disk flat and angular, rising a little towards its centre, cov- 
ered with thick, intimately soldered tuberculated plates having a porcelain 
surface; in the centre is a rosette of six primary plates, one rounded and 
swollen in the middle, and five wedge-shaped, encircling it and separated 
from each other by five raised rows of small tuberculated angular plates which 
run to the margin of the disk. Radial shields roughly triangular, large, with 
a blunt angle inward, separated their entire length by a raised row of angular 
plates ; on their outer edge are two more, which are small, rounded, and swollen. 
The interbrachial spaces above are wholly covered by the five radiating rows 
of plates and by a part of the radial shields ; and below by a few swollen scales, 
Genital openings extending to margin of disk ; narrow and close-shut without, 
but broadening into a sort of pore at their inner end, and bounded by small, 
swollen genital scales. Two short, stout, rounded arm spines, standing low on 
the plate ; they are about half as long as a side arm-plate, and the lower is a 
little the longer. One rounded, flat tentacle-scale on the inner side of the ten- 
tacle-pores. Color in alcohol, white with pale brown bands. 
Sigsbee, off Havana, 175 fathoms, 4 specimens, The arms were rolled round 
Stylaster filogranus, which the animal mimics by its porcelain surface, 
