528 CLARK 



Holothuria impatiens (Forskal). 



The collection contains 3 much contracted specimens, from 60 to 1 20 

 mm. in length, of this almost cosmopolitan species, collected at Tagus 

 Cove. The Galapagos specimens are distinguishable at a glance from 

 those from the West Indies, which also seem to answer the descrip- 

 tion, and I feel reasonably sure that the specimens from the Caribbean, 

 which have been referred to this species, are really perfectly distinct. 

 The Galapagos specimens seem to resemble the East Indian form. 

 They are brownish-grav, with large papillae, many of which are almost 

 white. The skin is very rough. Theel has reported this species from 

 Charles and James Islands, in the Galapagos. 

 Holothuria marenzelleri Ludwig. 



There are eleven specimens from the reef near Tagus Cove, which 

 agree admirably with Theel's description of specimens from Charles 

 and James Islands. This species was originally described fromNang- 

 kauri, and may therefore be regarded as an East Indian form. The 

 individuals before me ai-e from 60 to 100 mm. long, and have a stone- 

 canal 25 to 30 mm. long. 



The only other holothurian known from the Galapagos is 



Holothuria arenicola Semper. 



An East Indian species collected by the Hassler expedition. 



COMPARISON OF GALAPAGOS AND BERMUDAN ECHINODERMS. 



It is interesting to compare the Galapagos fauna with that of the 

 Bermudas, since the latter islands are similarly isolated from the main- 

 land. Leaving out of account the crinoids and deep water forms, 40 

 species of echinoderms are known from the Bermudas, and only 31 

 from the Galapagos. The four classes are represented as follows : 



Viewed thus, the most interesting differences between the two 

 faunae are to be found among the Asteroids and Holothurians. Star- 

 fishes are noticeably uncommon in the Bermudas, while they are very 

 common in the Galapagos ; exactly the reverse conditions exist among 

 the Holothurians. In the latter case, however, the real explanation 

 may lie in our imperfect knowledge, for Holothurians are easily over- 

 looked, and, even when found, are difficult to preserve, so that few 



