MUSEUM OF COMPARATIVE ZOOLOGY. 193 
Agassizia excentrica A. Ac. 
Station No. 20, Lat. 23° 02.5’ N., Long. 83? 11/ W. 220 fms. 
Station No, 36, Lat. 23° 13! N., Long. 89° 10' W. 86 fms. 
Station No. 21, Lat. 23° 02 N., Long. 83? 10 W. 287 fms. 
(Sigsbee.) Off Havana. Lat, 22° 09! N., Long. 82? 11/ W. 242 fms. 
Meoma ventricosa Lurk. 
Station No, 10, Lat, 24° 44’ N., Long. 83° 26' W. 37 fms. 
Station No, 36, Lat. 23° 13' N., Long. 89° 10 W. 84 fms, 
(Sigsbee.) Off Havana, 127 fms. 
Schizaster (Periaster) limicola A. Aa. spec. nov. 
Plate IIL. 
Station No. 49, Lat. 28? 513! N., Long. 89° 012 W. 118 fms. 
This species belongs to the generic group of Schizaster, separated as Periaster 
by D'Orbigny from the genuine Schizaster. Test quite globular, in outline 
from above angular, posterior extremity vertically truncated, slight keel be- 
tween posterior petals near apex; anterior extremity truncated vertically from 
the edge of ‘the peripetalous fasciole, with a shallow ambulacral groove. The 
lateral anterior petals are nearly twice as long as the posterior one, as well as 
broader. The petals are all about equally sunken. The peripetalous fasciole 
is in shape and position that of Schizaster proper, but there is no lateral fasciole 
extending under the anus, as in Schizaster proper ; the anal fasciole is narrow, 
extending only a short distance on the sides of the test. 
The test is thickly covered with primary tubercles of a uniform size, carrying 
short, slightly curved spines on the sides of test. The tubercles are more 
crowded within the fasciole and on the abactinal region of the odd posterior 
interambulacral area. The coronal plates between the fasciole and the anal 
system are quite bare, with few tubercles on the outer edges. On the actinal 
side the primary tubercles are larger, more distant, except on the actinal plas- 
tron, where they are closely crowded and carry longer, larger, and curved pri- 
mary spines. The actinal lip is very sharp and prominent, one large row of 
exterior plates round the anterior edge of the actinostome, smaller, irregular 
plates within. Anal system quite small for such a large species. The separa- 
tion of this group of Schizaster as a generic type seems very doubtful. It is 
based solely upon the more globular outline of the test and the disconti nuity 
of the latero-anal fasciole. It may be convenient to form a subgeneric, group 
with these characters ; but when we get to such forms as Sch. ventricosus and 
Sch. japonicus, it certainly becomes very difficult, if not impossible, to draw the 
line of demarcation. We have something of the repetition of the numerous 
generic subdivisions attempted by Troschel in the genus Tripylus and its allied 
forms leading to Faorina and the like, while this is a deviation in the direction 
of such genera as Periaster, Epiaster, Hemiaster, and the like. The structure of 
the odd anterior ambulacrum of this species has all the characteristics of Schi- 
