232 E. A. ANDHEWS, 



Both the character of the fins and the diminution in bulk of the 

 gonads, by loss of one series, may be explained on the assumption 

 that they favor more active locomotion outside the sand. We have 

 evidence that this species is, to some extent, free-swimming in habit. 



In order to determine what taxonomic value should be attached 

 to the anatomical features of this Bahama lancelet it will be neces- 

 sary to review our knowledge of known Acraniates as far as it 

 concerns the systematic work upon members of the group and the 

 closely associated facts of geographical distribution. 



HISTORICAL. 



As is well known the first recorded account of Amphioxus was 

 that of Pallas (1), who in 1774 described a preserved specimen that 

 came from the Cornish coast. Though the fish-like characters of 

 this undoubted Amphioxus were recognized by Pallas (" quodque 

 prima facie referet Piscem Leptocephalum Gronovii ") it was de- 

 scribed and figured as a mollusc, Limax lanceolatus. 



This error was corrected by Costa (2) who more than half a century 

 later re-discovered the animal, on the shores of the Mediterranean, 

 and misled by the gill-like appearance of the pre-oral cirri, named 

 it Branchiostoma- lubrieum. There seems to be no doubt that this 

 account was published in 1834, though in a paper so difficult of 

 access that it is chiefly the author's statements made in the two 

 complete, illustrated descriptions (3) of 1838 and 1843 that we rely 

 on in selecting this name Branchiostoma as preferable to the one 

 commonly used, Amphioxus. 



This latter was given in 1836 by Yarrell (4), who included in his 

 "British Fishes" an illustrated account of a single specimen taken 

 by Mr. Couch, at Polperro on the Mediterranean, where it hap- 

 pened to be lying with its tail protruding from under a stone. 



Not knowing the work of Costa, though acquainted with the 

 description of Pallas, Yarrell invented the name Amphioxus lance- 

 olatus under which the animal soon became an object of much 

 interest and subject of many anatomical investigations. 



The older generic term was used again by J. E. Gray (5), in de- 

 scription of a new species B. Beleheri from Borneo. This was 

 obtained at the mouth of the river Lundu by Capt. Belcher of H. 



