OP AETS AND SCIENCES. 211 



where the tubercles are larger and on the actinal plastron and interam- 

 bulacral spaces ; peripetalous fasciole broad pentagonal in outline ; anal 

 system quite small ; anal groove shallow. — Station 232, 345 fathoms ; 

 Station 191, 800 fathoms. 



Tlemiaster zonatus, A. Ag., nov. sp. 

 The specimens of Hemiaster collected by the Challenger in the 

 vicinity of the locality from which Loven's H. expergitus was obtained 

 cannot be referred to it at present, although the differences between 

 them may be due merely to age. In this species the spines are uni- 

 formly distributed over the whole abactinal surface of the test, the 

 anal groove is deeper than in the preceding species, and the peripeta- 

 lous fasciole is also broader. This species is more globular in shape, 

 and closely allied to the cretaceous H. 'prunella. — Station 126, 750 

 fathoms. 



Rhinobrissus hemiasteroides, A. Ag., nov. sp. 



This is a much smaller species than the one which I figured in the 

 Revision of the Echini, and it is referred to the genus with some doubt, 

 as this species presents characters which remind us strongly of Metalia 

 (the peripetalous fasciole) and of Brissopsis (anal fasciole), and even of 

 Brissus proper. It has, like Rhinobrissus, the odd ambulacrum flush 

 with the test, as well as the remarkably broad actinal ambulacral areas 

 round the actinostome, and the great length of the spines in the lateral 

 posterior interambulacra on the actinal side. It has, however, the 

 lateral petals much as in Metalia proper, as well as its subanal fas- 

 ciole, without the large anal branch so jirominent in Rhinobrissus. 

 The apex corresponds, also, as in Metalia, with the abactinal system, 

 and is nearer the anterior extremity, which is posterior in Rhino- 

 brissus. The spines of the abactinal surface are short, of uniform 

 size, whitish color in alcohol. — Tahiti Harbor, 20 fathoms. 



Schizaster claudicans, A. Ag., nov. sp. 

 This pretty little Schizaster is readily distinguished from its con- 

 geners by its high posterior extremity, nearly vertical, the sharp nar- 

 row clean-cut lateral fasciole, and the deeply sunken ambulacral petals 

 fringed by an indistinct peripetalous fasciole. It has a narrow actinal 

 plastron ; anal opening placed immediately under the abactinal edge 

 of the posterior interambulacral keel. Abactinal surface covered by 

 close uniform tuberculation above the ambitus ; odd anterior ambu- 

 lacral petal shorter than the anterior pair of petals. — Station 192, 

 129 fathoms. 



