758 



Between 1867 and 1881, four zoologists, Greef(3), Barrois(4), 

 Panceri(5), and Levinsen(6) recorded the finding of Chcetosoma 

 in such widely separated localities as the Canary Islands, Brit- 

 tany, Ischia, and Greenland, but added little or nothing to the 

 description given by Metschnikoff, though Panceri added another 

 species, C. tristicochceta Panceri. He himself considered this to 

 be a new genus, to which he gave the name Tristicochceta 

 inariyneiise', but it is now thought that the difference on which 

 he based his classification is not of generic importance. J>Jothing 

 further is recorded of Chcetosoma for twenty-six years. Then, 

 in 1907-1908, Schepotieff(7-8) published a brief, general account 

 of the group, including a description of two new species, which 

 he had found at Bergen and Naples. Seven years later, a short, 

 systematic description of two additional species appeared in a 

 paper by Southern in the CJare Island Survey Series (8). 



I have not had an opportunity of seeing the original papers 

 by some of the earlier workers (4-6), but Schepotieff states that 

 tiiey are all brief and superficial, and based almost exclusively 

 on studies of whole preparations. 



Levinsen's description is not made clear by illustrations, and 

 is so imperfect otherwise, that identification of the new species 

 he reported is uncertain. According to Schepotiefi'(8), it is pro- 

 bably identical with Chcetosoma tristicochceta. Greef (3) confines 

 himself to the statement that he frequently found Chcetoso7na 

 in different localities on the coast of the North Sea and the 

 Canary Islands, but, beyond a few new species (which he does 

 not describe or name), he could add nothing of importance to 

 Metschnikoff's description. His paper, on some remarkable 

 forms of Arthropod- and Worm Types, deals mainly with the 

 consideration of the systematic positions of tliis and other 

 genera, which he designates as remarkable creatures, new or 

 incompletely described, which bear in themselves the character- 

 istics of different classes of animals, without inclining, with any 

 decision, to one or other of them. He considers that the study 

 of these yet living transition-forms between different classes of 

 worms offers a great attraction to investigators, and demands as 

 complete an investigation as possible, from every point of view, 



