30 ANNUAL REPORT OF THE 



REPORT ON THE LOWER INVERTEBRATES. 



By Hubert Lyman Clark. 



Since taking up my duties at the Museum in December, 1905, 

 my time has been occupied almost exclusively with the collections 

 of Echinoderms. These collections have been looked over and 

 arranged systematically, preparatory to labelling and cataloguing, 

 and are found to contain about thirty-two thousand specimens. 

 The contents of the large jars and trays of unidentified Echino- 

 derms have been sorted and placed in their proper places in the 

 collections. The work of labelling and cataloguing the starfishes 

 is well under way, but has been delayed by the fact that much of 

 the material has never been identified, while even when specimens 

 are labelled it is frequently desirable to verify the identification. 

 Considerable time has been given to the critical study of the 

 collection of over fifteen huudred sea-urchins of the Cidaridae, and 

 to the preparation of a report on the same. There have been 

 few additions to the collections during the year ; the more impor- 

 tant are my own collection of Echinoderms, 171 species, 1,494 

 specimens and twenty-eight species of Sponges (U. S. Fish Com- 

 mission Steamer " Albatross " 1891 expedition) and seven species 

 of Corals (U. S. Fish Commission Steamer " Albatross " 1904-05 

 expedition) presented by the U. S. National Museum. 



