1888-89.] Mr John Rattray on the Genus Coscinodiscus. 657 
truncate, those bordering the subobsolete interval more oblique and 
concave inwards at the middle; areolae delicate, decreasing outwards 
from 9 to 14 in ’01 mm.; the intervals attenuating slightly outwards, 
their outer ends expanded and knob-like, not reaching the border. — 
Asterolampra shadboltiana, Grev., Trans. Mier. Soc. Lond ., 1860 
p. 121, pi. iv. fig. 19. 
Distinguished from A. Brookei by the outline of the centro- 
lateral space, the less marked geniculation of the radii, and the 
relatively shorter intervals between the compartments. 
Habitat. — Indian Ocean soundings, 2200 fathoms, Captain Pullen 
(Greville !); Mejillones (Grove !). 
Asterom. roperianus. Ralfs in Pritch. Inf., p. 838. — Diam. *07 
to *165 mm. Centro-lateral area with inner end angularly rounded, 
the sides sharply constricted and expanding thence to their outer 
ends. Markings : rays bigeniculate at their middle ; the flexions 
more pronounced on the rays proceeding from the sides than on 
those passing from the extremity of the centro-lateral area; the 
compartments reaching to § of radius inwards, their inner ends 
transversely truncate, those adjacent to the subobsolete interval 
more oblique; areolae 12 to 16 in '01 mm., obscure; the intervals 
broad, their edges parallel, the outer ends sometimes slightly 
expanded, not reaching the border.— Sch., Atl., pi. xxxviii. fig. 15 ; 
Asterolampra roperiana , Grev., Trans. Mier . Soc. Lond., 1860, 
p. 120, pi. iv. fig. 14; Mesasterias abyssi, Ehrb., Abh. Ber. Ak., 
1872, p. 392, pi. ix. fig. 7. 
Habitat. — Indian Ocean soundings, 2200 fathoms, Captain 
Pullen (Roper ! * Greville!); Mejillones guano (Deby! Grove!). 
Asterom. Brookei. f Bail., Amer. Jour. Sci., vol. xxii. ser. 2, 
1856, p. 2, pi. i. fig. 1. — Diam. *0725 to '075 mm. Centro-lateral 
area with a median constriction, its central end sometimes trans- 
versely truncate or subrotund. Markings : rays straight or slightly 
flexuous, sometimes sharply bigeniculate towards their outer 
extremities, with short lateral rami proceeding from the angles; 
the compartments reaching from f- to I of radius inwards, their 
inner ends tranversely truncate or slightly concave inwards, some- 
* In the collection of Dr R. K. Greville. 
t Named in honour of Lieut. Brooke of the U.S. Navy. 
VOL. XVI. 7/11/89 2 T 
