830 The American Naturalist. [September, 
3. Tentacles nodulated. Aurelianide. 
b. Tentacles of two forms. 
1. Marginal tentacles cylindrical; dise tentacles wart-like, 
branched or foliate. Rhododactide. 
2. Marginal tentacles pinnate; dise tentacles wart-like. 
ymanthide. 
c. Tentacles of various forms, not eylindrical. Cryptopdendride. 
- It is a pity that the Government cannot provide good illustrations 
for papers like this, but like all the publications of the Fish Commission 
it has put up with unsatisfactory photo-cuts. 
Maioid Crabs in the National Museum .—Miss Mary J. Rath- 
bun continues’ her studies of the Maioid Crabs by an account of the 
species of the family Maiid: in the National Museum. She enumera- 
tes 39 species as occurring in the collection and gives a list of desiderata 
which includes 100 species. The new forms described are Chionecetes 
tannerti, Celocerus grandis, Lepteces (n. g.) ornatus and Hyastenus car- 
ibbeus. The paper concludes with an extract from the as yet unpub- 
lished MSS. of the late Dr. Stimpson, a part of his final report upon 
the Crustacea of the Ringold and Rodgers Expedition to the North 
Pacific. The value of this last would have been increased by including 
references to the preliminary report on the same expedition published 
in the Proceedings of the Academy of Natural Sciences of Philadel- 
phia for 1857. 
A New Lancelet.’—Dr. E. A. Andrews regard the small lancelet 
which was found by the Johns Hopkins Marine Station in the Baha- 
mas as the type of a distinct genus of Acraniata to which he has given 
the name Asymmetron lueayanum. The chief anatomical peculiarities 
of the form are found in the asymmetrical character of the reproduc- 
tive organs, which occur on the right side of the body alone, in the 
absence of fin-rays from the ventral fin and in the presence of a long 
caudal process extending posterior to the last myotome. Dr. Andrews 
has also collected the literature of the various species of Amphioxus 
from which we learn that the following species have been described 
from the world. 
. Branchiostoma lanceolatum: Scandinavia, England, Mediterranean, 
Chesapeake Bay? Fiji Island? 
B. caribeum: Mouth of La Plata, Brazil, St. Thomas, Jamaica, 
? Proc. Nat. Mus., XVI, p. 63, 1893. 
.* Studies from Biol. Laby., Johns Hopkins, V, 1893. 
