582 A. WILLEY. 



(1903)/ W. M. Tattersall (1903),2 aud G. H. Parker (1904).3 

 Two other species have been added by Dr. Goldschmidt, A. 

 valdivice and A. stenurus. All three species were taken 

 during the '' Valdivia " Expedition at considerable depths in 

 the vertical tow-net in the high seas, often several hundred 

 miles from the nearest coast. Specimens were also obtained 

 in the Atlantic Ocean ;^ the distribution of the genus is there- 

 fore circumequatorial, but there is no correlation between 

 the specific forms and their geographical range. In the Bay 

 of Bengal, 300 miles east o£ Ceylon, twelve examples were 

 captured simultaneously at one station between a depth of 

 2500 metres and the surface, of which nine belonged to A. 

 valdiviee, three to A. pelagicus. Off the west coast of 

 Africa A. valdivise was taken south of Teneriffe and A. 

 pelagicus in the Gulf of Guinea. Lastly, all three species 

 have been taken in the neighbourhood of the Seychelles. 



No sexually mature individual has yet been seen. Dr. 

 Goldschmidt has found the immature gonads developing only 

 on the right side, lying in the gonocoel which is shut off from 

 the ventral ends of the myotomes. No specimens in the 

 "Valdivia'^ collection exceed 10 mm. in length. At this size 

 the gonads were observed to be as far developed as in a 

 Branchiostoma lanceolatum of 28 mm. 



• C. F. Cooper, " Ceplialocliorda," ' Fauna and Geography of the Maldive 

 and Laccadive Archipelaj^oes ' (J. Stanley Gardiner), vol. i, part 4, 1903, p. 352, 



2 W. M. Tattersall, "Report on the Ceplialocliorda collected by Professor 

 Herdman at Ceylon in 1902," 'Ceylon Pearl Oyster Fisheries,' part 1, 1903, 

 p. 214. 



^ G. II. Parker, "Maldive Cephalochordates," 'Bull. Mas. Harvard,' vol. 

 xlvi, 1904. 



* It is interesting to note that no examples were procured during the 

 " Plankton " Expedition. Hensen (Einige Ergebnisse der Plankton Exped., 

 1892, p. 24 — 25) says that they frequently obtained young Aniphioxus 

 lanceolatus u|) to some centimetres in length, as many as two to ten indivi- 

 duals in one catch of the Plankton Net in the North Atlantic. He notes that 

 it is remarkable that they should remain so long at the surface over great 

 depths, because Amphioxus is a coastal and littoral form, only the larvrc 

 being pelagic in the coastal zone. These observations are important as indi- 

 cating that the prolongation of the pelagic life docs not involve a persistence 

 of the larval asymmetry in A. lanceolatus. 



