238 E. A. ANDREWS. 



ACRANIATA. 



Genus BRANCHIOSTOMA. Gonads present on both sides; ventral 

 fin with fin-rays ; no caudal process. 



1. B. lanceolatum: formula 36 . 14 . 12 = 61, length 37 mm. Dis- 



tribution, Scandinavia, England, Mediterranean, Chesapeake 

 Bay? Fiji Islands? 



2. B. caribceum : formula 35 . 14 . 9 = 58, length 43 mm. Distri- 



bution, Mouth of La Plata, Brazil, St. Thomas, Jamaica, 

 Tampa Bay and Gulf of Mexico, Beaufort, N. C. 



3. B. cultellum .- 1 formula 32 . 11 . 10 = 52, length 23 mm. Distri- 



bution, Moreton Bay and Thursday Island, Australia. 



4. B. bassanum: formula 44 . 14 . 17 = 75, length . Distri- 



bution, Bass Straits, Australia. 



5. B. belcheri: formula 37 . 14 . 14 = 65, length 65 mm. Distri- 



bution, Borneo and Torres Straits, Australia. 



6. B. elongatum: formula 49 . 18 . 12 = 79, length 60 mm. Dis- 



tribution, Chinchaoarna, Peru. 



7. B. Calif orniense: formula 44 . 16 . 9 = 68, length 70mm. Dis- 



tribution, San Diego, California. 



Genus ASYMMETRON ; Gonads present only on right ; ventral fin 

 with no fin-rays ; a long caudal process. 



8. A. lucayanum: formula 44 . 9 . 13 = 66, length 13 mm. Distri- 



bution, Bimini and Nassau Harbor, Bahamas. 

 In addition to the species enumerated above there are records 

 of lancelets found in other regions that extend the area of geo- 

 graphical distribution and may modify our conception of the num- 

 ber of specific forms when all these specimens shall be re-studied. 

 At present, then, the geographical distribution of the Acraniata may 

 be summarized as follows : 



EUROPE. Scandinavian, British, and Italian Coasts : (1) B. lan- 

 ceolatum. 



ASIA. Borneo: (1) B. Belcheri. Japan: (2) ? (3) 



Ceylon; ? 



1 Mr. Arthur Willey of Columbia College informs me that he finds only right 

 gonads in this species ; so I judge it should be referred to the genus Asymmetron, 

 in a future revision of the Acraniata. 



