234 BULLETIN OF THE 



Sigsbeia murrhina sp. nov. 



Plate III. FIsrs. 66-58. 



Special MarJcs. — Arms stout, and in length aboxxt 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 Individxml. — Diameter of disk 12 mm. Length of arm 

 about 80 mm. Width of arm close to disk 5 mm. Nine to eleven irregular 

 crowded mouth-papillse 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 thi-ee or four are somewhat wider 

 than long, slightl}' 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 shiekls 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, wliich 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 ])ale brown bands. 



Sigsbee, oflf Havana, 175 fathoms, 4 specimens. The arms were rolled round 

 Stylaster fUogranus, which the animal mimics by its porcelain surface. 



