OPHIURANS OF THE PHILIPPINE AND ADJACENT WATERS. 167 

 AMPHIODIA CRASSA (Koehler). 



Plate 69, fig. 11. 



Amphiura crassa Kcehleb ('04), p. 83, pi. 15, figs. 1, 2. 

 Amphiodia crassa H. L. Clakk ('15), p. 249. 



Localities. — Albatross station 5145; vicinity of Jolo; Jolo Light 

 bearing S. 16° E., 1.57 kilometers (0.85 mile) distant (lat. 6° 01' 

 30" N., long. 120° 59' 30" E.) ; 42 meters (23 fathoms) ; February 

 15, 1908; co. S., Sh. 



One specimen (Cat. No. 40951, U.S.N.M.). 



Albatross station 5261; off southeastern Mindoro; Balanja Point 

 bearing N. 80° W., 11.1 kilometers (6 miles) distant (lat, 12° 30' 55" 

 X., long. 121° 34' 24" E.) ; 265 meters (145 fathoms) : June 4. 1908; 

 8., M. 



Three specimens (Cat. No. 40952, U.S.N.M.). 



Albatross station 5282; China Sea, in the vicinity of southern 

 Luzon; Malavatuan Island (N.) bearing S. 84° W., 11.5 kilometers 

 (6.2 miles) distant (lat. 13° 53' 00" N., long. 120° 26' 45" E.) ; 

 453 meters (248 fathoms) ; July 18, 1908 ; dk. gy. S. 



One specimen (Cat. No. 40953, U.S.N.M.). 



Notes. — The specimens are all of small size, and the diameter of 

 the disk scarcely reaches 3 mm. They are therefore very much 

 smaller than the type in which the diameter of the disk was 12 mm 

 I show here the ventral surface of the specimen from station 5282. 

 and it may be noticed that in this young individual the external 

 mouth papilla is broader than the two others; from this it may be 

 asked whether the species should not be placed in the genus Amphi- 

 phvlis, but as in the adult the three papillae have almost the same 

 dimensions and collectively form a very regular row, the assignment 

 of the species to the genus Amphiodia is more correct ; this is also the 

 classification adopted by H. L. Clark in 1905. I may remark also 

 that in these young specimens the oral plates are low, broadened, 

 and triangular, while in the Siboga specimens they are short and 

 rounded. 



Apart from these differences in the form of the external mouth 

 papilla and of the oral plate, these young specimens agree entirely 

 with the type; the dorsal plates of the disk have exactly the same 

 characters, and the arm spines are always five in number, the first 

 ventral being very strongly thickened. 



The type of A. crassa was found by the Siboga in the Sunda 

 Archipelago at depths between 450 and 2,291 meters (245 to 1,250 

 fathoms). The Albatross specimens were dredged at depths of 42, 

 265, and 453 meters (23, 145, and 248 fathoms). If there has not 

 been an error in the labeling, the very great range in depth between 



