THE HOLOTHURIOIDEA COLLECTED BY THE 

 VELERO HI AND IV DURING THE YEARS 



1932 TO 1954 



PART II. ASPIDOCHIROTA 



(Plates 1-9) 

 Elisabeth Deichmann 



Introduction 



No other tropical coast has ever been so well explored for shallow 

 water holothurians as the Panamic region of the west coast of America, 

 where the Hancock expeditions have collected for more than a decade. 

 The report on the dendrochirotes, 1941, included about 40 species, of 

 which many were new, and in most cases it was possible to outline the 

 distribution for each species with some accuracy. The collections of 

 aspidochirote forms are not so rich in species — only about half as many 

 as the dendrochirotes, and few are new — but the enormous amount of 

 material (some thousand individuals) has helped to clarify our ideas 

 about these widespread forms, their distribution, their ecological de- 

 mands, and the relationships of the Panamic shore fauna to that of the 

 West Indies and the outposts of the West Pacific. 



Like the dendrochirote forms, the aspidochirotes were almost un- 

 known in that part of the world thirty years ago. Mortensen's few 

 collecting trips in the Gulf of Panama, in 1916-1917, gave the first 

 inkling of how much existed in that apparently barren region. One 

 hesitated then to give names to these various species, as the few known 

 forms were inadequately described and it seemed impossible that some 

 of the more striking ones of those collected were not known from other 

 parts of the world. Hence the publication of the report on his material 

 was shelved for the time being. 



A large amount of the Hancock material was identified in 1933, 

 shortly after it had been collected, and more was worked over during 

 my various visits to California in the following years. During this time 

 short reports were published on material received from other expeditions 

 {Zaca, Arcturus, Stranger, etc.), slowly adding to the handful of species 

 hitherto listed. A preliminary report on the Hancock collections was 



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