Narrative of Bahama Expedition. 171 



the Pourtales Plateau some of these forms came up by the 

 hundreds, and proved that the\' were even more abundant 

 than the regular serpent-stars. The most common and strik- 

 ing species of this interesting group was Ophiocrcas hiinhricus 

 Lyman, in which the sharply defined radial ridges run nearly 

 to the centre of the disk. The spine-like tentacle-scales are 

 in pairs, the lower being about twice the length of an arm- 

 joint. The whole animal is covered with a smooth skin, and 

 the long arms look like earth-worms; hence the name, — 

 '•lumbricus.*' Alcoholic specimens give no adequate idea of 

 these striking forms. They were very conspicuous as they 

 came up on the dredge or tangles, being of a bright orange 

 color. The rays of the largest specimen vv'ere fullv two feet 

 long, making a spread of over four feet for the entire animal. 

 This is the largest measurement that I have heard of for any 

 Ophiuran. The disk itself is not over one inch in diameter, 

 seeming ridiculously small in proportion to the length of the 

 rays. It can easily be imagined that we were somewhat 

 excited when the first deep-water haul in that region brought 

 up a dozen or so of these brilliant creatures. It was no easy 

 matter, however, to extricate the long, snake-like arms from 

 the tangles and from each other. In fresh specimens there is 

 no indication of the arm-joints, giving a particularly smooth 

 and even polished appearance to the arms. This species 

 formed the type of the genus Ophiocreas described b}' Lyman 

 from specimens brought back by the '• Blake."' We secured 

 a large series from depths varying from ninety to two hun- 

 dred fathoms. Indeed this seems to be one of the most char- 

 acteristic forms of the plateau. Another extremely abundant 

 simple-armed basket-lish is AstrogompJnis vallatus Lyman, 

 another generic type yielded bv the investigation of the 

 '•Blake" material. This species, although not so conspicuous, 

 is even more numerous in individuals than the last. The 

 arms are much shorter in proportion than in Opliiocrcas, and 

 the entire surface is strongly hispid. The disk is armed 

 with radiating lines and concentric circles of stumpy, thorny 

 spines, while the arms are annulated with rings of thorny 



