236 Miscellaneous. 
MISCELLANEOUS. 
The Bahama Amphioxus. By EK, A. AnpRews. 
In addition to the Amphioxus, or lancelet, found on the coasts of 
many parts of Europe, some five others have been reported from 
various parts of the world. Gunther recognizes these six as species 
of Branchiostoma, that name haying been given prior to the term 
Amphiowus. The chief specific characters that can be made out 
in the preserved specimens are the relative positions of anus and 
atriopore as expressed by the number of muscle-segments anterior 
to, between, and posterior to these openings. In addition to these 
forms there is an undescribed lancelet in California, which, as far as 
the above criteria may be trusted, belongs to a distinct species of 
Branchiostoma, and a Japanese form that may prove to be one of the 
known species. 
The great morphological interest attached to the lancelet as the 
simplest and, in many respects, the most primitive of known verte- 
brates makes the taxonomy and geographical distribution of this 
group of more than common importance, and justifies a short pre- 
liminary account of a new form found in the Bahamas. 
While the Johns Hopkins Marine Laboratory was stationed at 
North Bimini, Bahamas, in the summer of 1892, many small lancelets 
were taken swimming at or near the surface as well as living in the 
calcareous sand on the flats exposed at low water. 
These partly pelagic acraniates differ so much from the known 
forms that they may be regarded as generically distinct. Their chief 
anatomical peculiarities are as follows :— 
(1) The gonads are developedjonly upon the right side of the body, 
both in the adult and in the young. 
(2) The notochord, neural tube, and median fins are prolonged as 
a considerable caudal process posterior to the myotomes. 
(3) The ventral fin is without any fin-rays or successive fin-ray 
chambers. 
(4) The pre-oral hood is extensive ; cirri smooth and united by 
the hood-membrane for the greater part of their length. 
(5) The right metapleuron is continuous with the median ventral 
fin, which passes to the right of the anus. 
(6) The “olfactory pit” is apparently absent. 
(7) Myotomes anterior to atriopore 44, between atriopore and 
anus 9, posterior to anus 13: total 66. Length 13-16 milhim. 
(8) Swims free in the evening both at Bimini and in Nassau 
Harbour. Lives also in the caleareous sand. 
An illustrated description of these characters of this new genus 
of acraniates will appear in a forthcoming number of vol. v. of the 
* Studies from the Biological Laboratory.’—Johns Hopkins University 
Circulars, vol. xii. no. 106, p. 104. 
