42 THE VOYAGE OF H.M.S. CHALLENGER. 



Mttrama sp. 



A specimen, 3 inches long, obtained at the surface between Tenerife and St. Thomas, 

 West Indies, although very young, has all the characters of an adult fish, and no 

 trace of Leptocephaloid structure. The species cannot be determined. 



Leptocephalus, Gron. 



Singularly, few specimens only were collected during the expedition ; and these do 

 not throw new light upon the question of their origin. 



a-f. Obtained in Mid Atlantic on March 4, 1874. They belong to the form which 

 has received the name " pellucidus," and other names. The specimens vary 

 much with regard to the relative length of the body. 

 g. Off the west coast of Africa ; lat. 10° 55' N., long. 17° 46' W.; April 13, 1876. 

 a. Obtained on the west coast of Africa ; surface ; August 16, 1873 ; form, " Lepto- 

 cephalus morrisii." 

 a. Obtained near the Admiralty Islands, March 16, 1875; form, "Leptocephalus 



taenia." 

 a. North Atlantic; April 13, 1876; form, " Leptocephalus hrevirostris." 



V. PLECTOGNATHS. 



Balistes sp. 



Three specimens, 5 lines long, from driftwood, north of Papua ; February 21, 

 1875. 



Tetrodon sp. 



Two specimens, ^ inch long, at the^eurface, between Tenerife and St. Thomas, West 

 Indies. 



VI. LEPTOCARDII. 



Branchiostoma, Costa. 



The littoral specimens of Branchiostoma collected during the voyage, belong to 

 Branchiostoma belcheri, Gray, and Branchiostoma cultellum, Ptrs., and were obtained, 

 the former at Samboangan, the latter on the north coast of Australia. They are men- 

 tioned here, because they were received too late to be introduced into the Report on the 

 Shore Fishes. 



