LOXECHINUS. 347 



Station 3872. Off Mokuhooniki Islet, Auau Channel, Hawaiian Islands. 

 Bott. temp. 74.0°. 32-43 fathoms. Yl. s., p., co. 



Station 3876. Off Lahaina Light, Maui, H. I. Bott. temp. 74°. 28-43 

 fathoms. S., g. 



Station 4033. Off Diamond Head, Oahu, H. L Bott. temp. ? 28-29 

 fathoms. Fne. eo. s., for. 



Station 4164. Off Modu Manu, H. I. Bott. temp. 78.1°. 40-56 fathoms. 

 Co. s., p., sh. 



Bathymetrical range, 28-56 fathoms. Extremes of temperature, 78.1°-74°. 



Five specimens. 



Paracentrotus. 



Mortensen, 1903. "Ingolf" Ech., pt. 1, p. 124, 135. 

 Type-species, Echinus lividus Lamarck, 1816. Anim. s. Vert., Ill, p. 50. 



Although Mortensen does not designate lividus as the type of his genus, it is 

 without doubt the species he intended as the type, and therefore it is here 

 accepted as such. The similarity of this genus to Echinus is striking and 

 Mortensen is undoubtedly right in describing it as a polyporous Echinus. It 

 appears to be very near the parent stock from which the Strongylocentrotidae 

 have sprung. There are only three species known, lividus, which is found in the 

 Mediterranean and in the eastern North Atlantic from the English Channel to 

 the Azores and Canaries^; Gaimardi (Bl.), which appears to be confined to the 

 Brazilian coast; and agulhensis Dod., which occurs off South Africa, and in 

 much deeper water than the others, having been taken by the ''Valdivia" in 

 278 fathoms. The three species may be distinguished from each other by the 

 following characters : — 



Pores-pairs 4 in each arc. 



Unicolor; preserved material whitish or light yellowish agulhensis. 



Variegated; preserved material green and brown Gaimardi. 



Pore-pairs generally 5; color variable, but dark Hindus. 



LOXECHINUS. 



Desor, 1856. Syn. Ech. Foss., p. 136 

 Type-species, Echinus albus Molina, 1782. Saggio St. Nat. Chili, p. 175. 



Whether this genus contains more than a single species seems open to gra\-e 

 doubt, for it is not easy to believe that hullatus is distinct from albus. A series of 



1 Bell (1892, Cat. Brit. Ech., p. 158) records this species from Brazil. This is probably due to eon- 

 fusing lividus with Gaimardi, from which it is quite distinct. 



