xv ECHIUROIDEA SPECIES 441 



by rings bearing spines. Two or three (E. chilensis) pairs of 

 nephridia, their external orifice often lengthened and spirally 

 coiled. Both sexes alike. 



Greef 1 mentions six species of Echiurus, viz. E. pallasii, E. 

 forcipatus, E. sitchaensis, E. chilensis, E. carabaicus, and E. 

 chrysacanthophorus ; to these must be added E. unicinctus. It 

 seems probable that E. forcipatus of lleinhardt is identical 

 with E. pallasii, although bigger, whilst E. sitchaensis, E. cara- 

 baicus, and E. chrysacanthophorus are inadequately described. 

 The distribution of the remaining three species is as follows : 



E. pallasii Guorin (Fig. 223). North Sea, Atlantic, English Channel. 

 E. unicinctus Drasche. Japan. 

 E. chilensis Max Miiller. Chili. 



Thalassema. Proboscis rather pointed at the end, not bifur- 

 cated. No peri-anal bristles, but two ventral hook-like bristles 

 placed anteriorly. One to three or four pairs of nephridia. The 

 sexes resemble each other. 



Greef mentions eight species of Thalassema and Puetsch 

 thirteen ; three of these, however, Th. grohmanni, Th. lessonii, 

 and Th. pelzelnii, were not seen by either author, and their 

 description is taken from Diesing. There is some reason for 

 thinking that the two first-named species are identical with Th. 

 neptuni. Conn has established a new species for the specimens 

 whose embryology he worked out at Beaufort, Virginia, and 

 Selenka described a new species from the Challenger material. 



"With the exception of the three doubtful species mentioned 

 above, the list of species of Thalassema is as follows : 



Th. neptuni Gaertner (Fig. 224). English Channel (Devonshire coast), Con- 



carneau, Mediterranean (Gulf of Marseilles), Irish coast (Dungarvan). 

 Th. gigas Max Miiller. Trieste. 

 Th. vegrande Lampert. Philippine Islands. 

 Th. baronii Greef. Canary Islands (Lanzarote). 

 TJi.formosulum Lampert. Shanghai and Philippine Islands. 

 Th. exilii Fr. Miiller. Brazil (Desterro). 

 Th. moebii Greef. Mauritius. 



Th. erythrogrammon Max Miiller. Red Sea and East Indies (Billiton). 

 Th. caudex Lampert. Ked Sea and Indian Ocean. 

 Th. sorbillans Lampert. Philippine Islands. 

 Th. mellita Conn. West Atlantic (Beaufort). 

 Th. faex Selenka. North of the Faroe Islands. 



Ada Ac. German, Halle, xli. Tart II. No. 1, 1879. 



