wes 
2 Observations upon the Habits, Structure and (January, 
I have embodied in the following necessarily incomplete sum- 
mary of our present knowledge of Amphioxus, were conducted 
with a great deal of care, and while they have led me to differ 
from the commonly received views in regard to certain particu- 
lars of structure and development, they have enabled me, by a 
somewhat detailed comparison of results, to corroborate much of 
what has already been done in this important field of research. 
History—This apparently insignificant little creature was first 
made known to science, in the year 1778, from specimens found 
upon the coast of Cornwall, England, and sent to Peter Simon 
Pallas, a celebrated German naturalist, who was then issuing his 
Record of new forms of animal life. The description given in 
this Record? is, in the main, quite accurate, but from some migun- 
derstanding of the nature of the ventral ridges, or perhaps from 
` some slight resemblance to a sea-slug, Pallas considered it a new 
species of snail, and named it Limax lanceolatus. Had he had 
the opportunity of examining other than contracted specimens of 
this new form, he probably would not have written, “Tentacles . 
evidently none,’ and might have hesitated before placing it 
among the Limacidz. But if Pallas failed to correctly estimate its 
generic features, the next writer who mentions it? seems to have 
been able to appreciate them to a certain extent, for he remarks,- 
* 
that it is “ hardly a Limax,” although for some reason he retained 
this name, and adds to it, probably through some typographical _ 
error the: specific term of danceolaris, which ought only to accom- 
pany the genitive of Limax, or Limacis. After this notice by 
vocabulary of zoologists and to have passed almost from the 
memory of those engaged in describing and classifying new spe- — 
cies of animals, for in 1834, when Costa? discovered this same 
animal in the Bay of Naples, Italy, he failed to recognize it as 
having been « pecs before, and considering it a new species of — : 
having tentacles about the mouth, and upon the supposition that l | 
these tentacles subserved the purposes of respiration as branchia. _ 
'Spicilegia Zodlogica. Peter Simon Pallas. Fasc. x, p. 19. Taf. 1, Fig. H. - 
Berlin, 1778. j : 
_2£Elements of Natural History. . 
Stewart. 2d edition. Vol. 1, p, 386. 
; *Cenni Zodlogici ossia descrizione sommaria di talune specie nuove di antinali. 
O. G. Costa. Page 49- Napoli, 1834. And, Storia el Branchiostoma ibri 
Napoli, S 
Stewart, Limax lanceolatus seems to have dropped from the. : 
ey 
