100 HAWAIIAJ^ AND OTHER PACIFIC ECHINI. 



Station 4980. Between Kobe and Yokohama, Japan. Bott. temp. 39°. 

 507 fathoms. Br. m. fne. s. for. 



Station 5078. Off Omai Saki Light, Japan. Bott. temp. 38.9°. 475-514 

 fathoms. Fne. gy. s. glob. 



Station 5079. Off Omai Saki Light, Japan. Bott. temp. 39.1°. 475- 

 505 fathoms. P. 



Station 5080. Off Omai Saki Light, Japan. Bott. temp. 38.7°. 505 

 fathoms. Fne. gy. s. glob. 



Bathymetrical range, 475-514 fathoms. Extremes of temperature, 

 39.1°-38.7°. Fifteen specimens. 



Dermatodiadema. 



A. Agassiz, 1898. Bull. M. C. Z., XXXII, p. 76. 

 Type-species, DermafodiaJenMi glohulosuTn A. Agassiz, 1898. Bull. M. C. Z., XXXII, p. 76. 



The attempt of Pomel (1883) to divide Aspidodiadema into two genera, 

 without having any specimens before him, has led to a little confusion in 

 regard to the generic name for this group, but there seems to be general 

 agreement now that the name Plesiodiadema Pomel is quite unusable. This 

 genus contains six species, which are distinguishable fi'om each other with 

 more or less difficulty. One of them, antillarum A. Ag., is characteristic of 

 the West Indian region, where it occurs at depths of 157-1589 fathoms ; it 

 was also taken south of the Canary Islands, by the " Valdivia," in 1389 

 fatlioms. Two species, horridum and glohidosum, A. Ag., are known only 

 from the Panamic region, at depths of 902-1772 fathoms. The " Valdivia" 

 collected a species very near fflobulosum in the Indian Ocean at a depth of 

 1622 fathoms, which Doderlein (1901) has named 7nolle, and a second very 

 well characterized species, imlimm Dod., near Sumatra, in 261 fathoms. The 

 latter was taken by the " Siboga " also, in the Java Sea at 289, and in the 

 Banda Sea at 113 fathoms. The "Siboga" took a second species, south of 

 Celebes in 643 fathoms, which de Meijere (1904) has called amplug//mnum. 

 The three specimens were obviously immature, and we fail to find any 

 character by which they could be distinguished from horridum of the same 

 size ; the apparent difference in the anal system is neither sufHciently marked 

 nor constant to warrant their separation. The sixth species, which seems to 

 us valid, is microtuherculatum A. Ag., taken by the "Challenger" in the 

 southern Atlantic and Pacific Oceans, at depths of from 2025 to 2225 



