384 THE VOYAGE OF H.M.S. CHALLENGER, 
examples it can scarcely be discerned at all. This is caused by a difference in the form of 
the abactinal plates, although the circumstance is scarcely apparent superficially owing to 
their membranous covering. The presence of this band suggests the character produced 
by the different form of the median and lateral series of abactinal plates in Nepanthaa. 
Subfamily AsTERININz, Sladen, 1888. 
Genus Patiria (Gray), emend. Perrier. 
Patiria, Gray, Ann. and Mag. Nat. Hist., 1840, vol. vi. p. 290. 
Patiria, as constituted by Gray, was an ill-defined group, which included forms that 
cannot be separated by any essential character from Asterina. The genus was subsequently, 
and with great justice, limited by Perrier to one of the three sections made by Gray, and 
comprised only two species, those named by him Patiria ocellifera and Patiria crassa. 
This view of the genus is the only one which can be maintained. A third species has 
been added by the Challenger. That Patiria is very closely allied to Asterina there can 
be no doubt; and a young form which I have referred to the species described below 
indicates this affinity even more closely than the adult forms, and suggests the assumption 
that Patiria is probably immediately descended from an Asterina-like ancestor. As 
known at present the genus is confined to the southern hemisphere; but the locality of 
one of the original species is unknown. 
Chorology of the Genus Patiria. 
a. Geographical distribution :— 
ATLANTIC: One species between the parallels of 30° and-40° S. 
Patiria bellula, from Simon’s Bay, Cape of Good Hope. 
InpIAN OcEAN: One species between the parallels of 10° and 50° S. 
Patiria crassa from Western Australia. 
6. Bathymetrical range: Shallow water. 
y. Nature of the sea-bottom: Not recorded. 
Chorological Synopsis of the Species. 
Ocean. | Range in Fathoms, Nature of the Sea-bottom. 
| 
| 
| a0 ; 
Patiria bellula . ; | Atlantic. Shallow water. 
Patiria crassa . : ; Indian, 
Patiria ocellifera. ah 2 2 
