INTRODUCTION. 



Among the most interesting Ecliinoderms collected by the U. S. Fish 

 Commission Steamer " Albatross," on her voyage from New York to San 

 Francisco, are the Crinoids, which form the subject of this paper. 



They were collected at the Galapagos (off Indefatigable Island) in 392 

 fathoms. The material at my command consisted of one calyx badly torn 

 in being detached from its stem, with fragments of arms in sufficient num- 

 bers to enable me to reconstruct two arms completely ; a second calyx, 

 with quite a perfect disk and the base of all the arms attached, as well 

 as a short piece of the stem ; and a third calyx, with parts of the arms and 

 a portion of the upper part of the stem. This is the best preserved calyx. 

 Numerous fragments and longer or shorter pieces of the arms belonging 

 to these three specimens were collected, as well as pieces and fragments 

 of the stems. Fortunately, the portions of the stem which fitted on the 

 calyx were preserved for each specimen. 



During the last dredging trip of the " Albatross," (February to May, 

 1891,) which I was fortunate enough to accompany, we obtained off Maria- 

 to Point, in 782 fathoms, an additional specimen of Calamocrinus Diomedas. 

 When it first came out of the water it was of a brilliant lemon-color, with 

 a greenish tinge on the sides of the arms and along the food furrows of 

 the ventral surface. A colored sketch of the specimen was at once made 

 by Mr. Westergren, and this is reproduced in Plate XXVIII. of this me- 

 moir. Some minor differences in the structure of the stem are also shown 

 in the same plate, and more fully described in their proper place in the 

 memoir. Its base of attachment came up with a fragment of stem nearly 

 fourteen inches long. 



At first glance I was inclined to consider this Crinoid, from the charac- 

 ters of its stem, of the spreading uppermost joints, and of its interradial 



