XUCLEOLITIDAE. 103 



are no published records of the species having been met with and it is therefore 

 of interest to record that there are now in the M. C. Z. collection seven speci- 

 mens. Five are bare tests, four from the Hawaiian and one from the Society 

 Islands. Three of those from Hawaii were presented by Mr. D. Thaanum in 

 1913. On my writing Mr. Thaanum of the peculiar interest attaching to these 

 specimens and urging him to look out for the living animal, he promised to make 

 every effort to find it. At last in July, 1916, two specimens were secured 

 "from the sand, under coral rocks" on the beach near Hilo. Mr. Thaanum 

 writes: "The color I should call light olive while living, now darkened and 

 changed." The tube-feet, he notes, were "brownish-red." These two speci- 

 mens, beautifully preserved (dry) make up the seven in the M. C. Z. 



Compared with specimens of cyclostomus of their own size, these Hawaiian 

 specimens are not strikingly different in color but the difference in the spinula- 

 tion and tuberculation is most marked. The primary spines and tubercles 

 are very small but the perforation of the latter is perfectly distinct. De Loriol's 

 holotype was olive-green and was 52 mm. long by 45 mm. wide. The largest 

 of our Hawaiian specimens is 31 X 24 mm. It is worthy of note that both 

 species of Echinoneus were sent to de Loriol from Mauritius and we have both 

 species from the Society Islands and from Hawaii. Yet all the specimens 

 which Mr. Thaanum has collected near Hilo have proved to be abnormalis. 



Micropetalon. 



A. Agassiz and Clark, 1907. Bull. M. C. Z., 60, p. 251. 

 Type, Micropetalon purpureum A. Agassiz and Clark, 1907. Loc. cit. 



Westergren (op. cit.) has so fully described and beautifully figured ail the 

 details of the unique holotype of the only known species of this genus, that it 

 would be quite superfluous to add anything here. The specimen referred to 

 was taken by the Albatross. 



Station 3847. Off Lae-o Ka Laau Light, Molokai, Hawaiian Islands, 23-24 

 fms. S., st. 



NUCLEOLITIDAE Gregory. 



Although Hawkins (1911. Geol. Mag., n. s., decade 5, 8, p. 265) con- 

 siders this family diphyletic, the Recent species seem to form a very homo- 

 geneous group and I therefore retain here the single family but without its 

 long-familiar name Cassidulidae, which must be abandoned since Cassidulus is 



