136 Bulletin Vanderbilt Marine Museum, Vol. VII 



(Koehler) ; Fiji Islands (Ljungman) ; Fiji Islands, near Suva 

 (H. L. Clark); Ebon, Marshall Islands (H. L. Clark; Samoa 

 (Lyman, Clark; Tonga Islands: Tongatabu (Lyman); Hopai 

 (Studer) ; Society Islands (Ljungman, Lyman) ; Papeete, Society 

 Islands (H. L. Clark). 



Material examined: Two specimens, broken, brought up on 

 the "Alva's" anchor-chain, in Seba-Bay, South Brother's Island, 

 Durian Straits, Dutch East Indies, 22 fathoms, October 21, 1931. 



Technical description : The "Alva" specimen has the disk 

 diameter 20 millimeters ; the arm length is 330 millimeters. The 

 abactinal surface of the disk has the interradial areas large, each 

 being as wide at the narrowest point between the radialia as the 

 greatest width of one radial plate; this interradial area being 

 three approximate series of long spinules, this area widens to- 

 ward the circumference of the disk and here the long spinules 

 are equally numerous. The interradial areas converge toward 

 the center like the spokes in a wheel, this center being equally 

 beset with spines. The radial shields are five-sevenths as long 

 as the radius of the disk and are triangular, placed side by side, 

 being separated by only a linear area of skin which is slightly 

 the wider on the inner half of its length and bears here two to 

 three long spines ; otherwise the shields are naked except for the 

 encasing skin. Each shield is triangular with the apex directed 

 inward; the outer margin is oblique, terminating in a rounded 

 node at the inner side of the pair. The actinal surface has the 

 interbrachial region covered with a tough integument and bears 

 numerous spines similar to those of the abactinal surface, but 

 progressively decreasing in length from the disk circumference 

 toward the mouth where they are reduced to small denticles. The 

 long disk spines are somewhat primitively fluted longitudinally 

 with four to six ridges, the tips being flattish, the adjacent third 

 of the lateral margins and tip being serrulate with four to eight 

 coarse sharp teeth. The long abactinal disk spines are 2 milli- 

 meters long; the actinal spines are 0.8 to 1 millimeter long with 

 the tips only serrulate. The genital slit extends two-thirds of 

 the length from the mouth shield towards the circumference of 

 the disk. The mouth shield is widely oval, the width being nearly 

 one and a half times the length, with the outer margin widely 

 convex, the inner margins produced to a median subacute apex. 



