AGASSIZ: PRELIMINARY REPORT ON THE ECHINI. 83 
Toxobrissus pacificus A. Ac. 
Plate XI. Figs. 4, 5. 
There occurs in the Pacific a Spatangoid which has been regarded as allied 
to Brissus. Specimens of it are known to me from the Sandwich Islands and 
from Zanzibar. A species closely allied to the above mentioned specimens has 
been dredged off Point Mala, at Station No, 3355, in 182 fathoms. I am in- 
clined at present to place these specimens in the genus Toxobrissus of Desor. 
The species dredged by the Albatross are marked for the flatness of the test, 
the confluence of the posterior ambulacra along the median line for nearly 
half their length, the great width of the posterior extremity of the test, the 
large and uniform size of the posterior ambulacral plates on the actinal side 
of the test, as well as the small size of the actinal plastron. 
SPATAGODESMA, A. Ae. 
Plate XII. Fig. 8. 
From Station 2769, during the voyage of the “ Albatross” from New York 
to San Francisco, were obtained specimens of a small species of Spatangoid, 
in which the character of the apical fasciole differs widely from that of any 
Spatangoid known to me. It possesses a broad elliptical fasciole encircling 
both the ambulacra and the anal system. A transverse band divides the fas- 
ciole into two areas, one enclosing the anal system and the other becoming the 
peripetalous fasciole. Such a fasciole is unknown to me, and among the young 
Spatangoids I have had occasion to examine nothing similar exists. The near- 
est approach to the fasciole of this genus, for which I propose the name Spata- 
godesma, seems to exist in the young of Agassizia, in which an imperfect 
subanal fasciole branches off from the peripetalous fasciole. The actinostome 
is still quite central, and no prominent posterior labrum is as yet developed in 
the largest specimen, which is about 7 mm. in length. I have not yet been able 
to satisfy myself of the relations of this interesting Spatangoid. 
