EASTERN TROPICAL PACIFIC ASTEROIDEA. 



INTRODUCTION. 



The collections of sea-stars made by the Albatross on her Tropical Pacific 

 expeditions were not large, but as they contained much valuable material from 

 deep water they were entrusted to Prof. Hubert Ludwig, by whom the report 

 on the Panamic collection of 1891 was prepared. The collection made in 1899- 

 1900 contained but forty-two specimens of thirteen species, of which ten were 

 well-kno\ATi Uttoral forms while three were deep-sea species, new to science; 

 these thirteen species are included in the Memoir on the Panamic starfishes 

 which was pubUshed in 1905 (Mem. M. C. Z., 32). The collection made in 

 1904-05 was much larger and Ludwig never completed his work on it. In 1907 

 (Zool. ,\nz., 31, p. 312-319) he published a preUminary description of five new 

 species and a new variety of PorceUanasteridae, but his study of the other 

 famiUes was unfinished at the time of his death in 1913. Later the collection 

 was sent to Cambridge together with his notes, some of which were apparently 

 in form for pubhcation. It was at first thought that these notes would be of 

 ser\'ice in the preparation of the present report, but it soon became evident that 

 the correlation between the notes and the collection was too imperfect to permit 

 this. There are notes on species, including descriptions of new forms, which 

 are not in the collection as returned to Cambridge and there are many species 

 in the collection not mentioned in the notes. Under the circumstances there- 

 fore, I have decided to base this report exclusively on the collection as returned 

 to Cambridge. 



The collection at present consists of 235 specimens of twenty-eight species 

 and one variety, but 148 of the specimens represent three species and four 

 additional species total fifty specimens. Three fom-ths of the species therefore 

 are represented on an average by fewer than two specimens each. Of the twenty- 

 eight species, six are littoral and twenty-two are deep-water forms. Of the 

 httoral species, five are conmion and long-known species, while one is of ex- 

 ceptional interest, being a new asteriid from Easter Island. Of the deep-water 

 species, eight are as yet undescribed forms while five others were new to science 

 when the collection was sent to Ludwig; these (as already stated) have been 



