120 BULLETIN OF THE 



Ophiomusium flabellum sp. nov. 



Plate V. Figs. 141 - 143. 



Special MarJcs. — Basal side arm-plates very flat and ^vide, encroaching 

 much on the interbrachial space, and bearing stout spines on their outer edge. 

 First under arm-plate siniilai- to those beyond, and lurnisbed with a tentacle- 

 scale. First side arm-plates meeting on median line of lower interbrachial 

 space. 



Description of an Individual. — Diameter of disk 3.3 mm. Length of 

 arm 3.3 mm. Width of arm close to disk, without spines, 1 mm. Mouth- 

 papillae closely soldered together, forming a continuous line. Large triangular 

 mouth-frames. Mouth-shields minute, diamond-shape. Side mouth-shields 

 very large, meeting broadly within, with outer ends wide and much rounded, 

 having a re-entering curve on the lateral edge, where stands the tentacle-scale. 

 First, second, and third under arm-plates pentagonal, with a blunt angle within, 

 outer edge slightly curved, and lateral sides re-enteringly curved ; the second is 

 largest of the three ; the fourth and last is a minute, broad, triangular scale, 

 without a tentacle-pore. The first pair of side arm-plates are swollen, and of such 

 extraordinary size as to meet on the median line of the interbrachial space ; the 

 second are smaller, and meet above and below ; beyond the fourth under arm- 

 plate they form the entire covering of the arm. Only two miniite triangular 

 upper arm-plates, having the outer edge slightly curved. Disk high and 

 round, covered with thick, much swollen plates, whereof the middle are some- 

 what sunken ; the central primary is pentagonal, surroxinded by a row of angu- 

 lar plates, of nearly equal size ; outside this row, in each interbrachial space, is 

 another angular plate separating the inner ends of the rather long, closely 

 joined radial shields. On the interbrachial margin is a large, much swollen 

 boss, rising high above the other disk-plates, and connecting the neighboring 

 radial shields. On the interbrachial space of the under surface there is but 

 one minute triangular scale, outside the enormous first pair of side arm-plates ; 

 these carry on their outer edge three small blunt spines, which look like mar- 

 ginal disk-papillce ; the next pair carry only two spines ; and beyond, there is 

 only one, which is blunt and short, and carried low on the outer edge of the 

 plate. Only three pairs of tentacle-pores (including the mouth-tentacles), each 

 Avith one large rounded scale on the lateral sides of the under arm-plates. 

 Color in alcohol, very pale brown. 



This species and 0. pulchellum, by their large flat side arm-plates of the first 

 pair, and peculiar first under arm-plate, which bears tentacle-scales, are strongly 

 distinguished from others of the same genus. 



Off Port Jackson, 30 - 35 fathoms, 1 specimen. 



OPHIOPYRGUS pen. nov. 



Disk high and donje-shajK-il, covered with tliick swollen plates, and sur- 

 mounted by a central primary plate, which rises like a cone. Arms slender, 



