ECHINODERMATA 525 



brown, but in some specimens the upper side of the disc is light ; in one 

 specimen pale yellowish-white ; in the smallest specimens, the upper 

 side of the arms is more or less clearly banded with dull purplish, 

 brownish-olive, and yellowish. The largest specimen has the disc 16 

 mm. across, and arms 105 mm. long; the smallest is 7 mm. across, 

 and has arms 45 mm. long. Easily distinguished from any of its near 

 relatives by its color and arm-spines. 



Ophiocoma aethiops Liitken. 



Of this huge species, the collection contains a single dry specimen 

 from Narboro and five alcoholic specimens from Iguana Cove. The 

 dry one is the lai'gest ophiuran known to me, the disc being 40 mm. 

 in diameter ; unfortunately all the arms are broken. It resembles the 

 common West Indian species, O. echinata^ superficially, but is easily 

 distinguished by its finer disc granulation, the wider arms, and the dif- 

 ference in shape of the oral shields and upper arm plates. Previously 

 reported from Lower California and the west coast of Central Amer- 

 ica ; it was collected at the Galapagos by the Hassler Expedition. 



Ophiothrix spiculata LeConte. 



There are two dry specimens from Narboro and three alcoholic 

 from Iguana Cove. The disc of the largest one is 12 mm. across and 

 and the arms less than 50 mm. long. The diversity of color is very 

 remarkable. One of the dry specimens is dark purplish-blue, with the 

 under arm-plates marked with yellowish-white, and the arm-spines 

 dark dull purple. The other has the disc and basal half of arms yel- 

 lowish, the center of disc, interbrachial spaces, and upper arm-plates 

 clouded with dark blue ; the arm-spines are light and clear, and just 

 tipped with purple ; the terminal half of the arms is dark blue as in 

 the first specimen and the transition from yellow base to blue tip is 

 very abrupt. The alcoholic specimens are intermediate in color be- 

 tween these two, but approach much more nearly the dark one. This 

 also is a western Central American species. 



The following species previously taken at the Galapagos, are not in 

 the Hopkins Stanford collection. 

 Ophionereis annulata Liitken. 



A western Central American species. 



Ophionereis nuda Liitken and Mortensen. 



Collected near Chatham Island by the Albati'oss^ and not known 

 from any other station. 

 Amphiura verticillata Ljungman. 



Peculiar to the Galapagos. 



