VESPERTILIONIDA. — CXC. 329 
566. PLECOTUS Geoffroy St. Hilaire. (méke, to fold; 
ous, ear.) 
a. Nostril without ‘‘rose-leaf’’ or disk-like appendage. (Corynorhinus 
H. Allen.) 
1086. P. macrotis (Le Conte). Bric-zarep Bar. Blackish; 
fur soft and long. L. 3}. E. 11. T. 138. Va. to Dak. and S. 
(pakpos, large ; ovs, ear.) 
OrpeR LI. CETE, (Tue CetTaceans.) 
Mammals of the sea, more or less fish-like in form, and adapted 
for life in the open ocean. Bones of the neck short, more or less 
fused; posterior limbs wanting; pelvis rudimentary; anterior 
limbs developed as broad, flattened paddles, without distinct fingers 
and without nails. Nostrils developed as spiracles, and opening 
usually on top of head, thus enabling the animals to breathe with- 
out raising the head from the water; eyes small; no external ear; 
skin nearly or quite destitute of hair; tail ending in a broad hori- 
zontal fin or paddle ; back sometimes with a dorsal fin. Skin thick 
and tough; beneath it a thick layer of fat (blubber), which pro- 
tects the animal from the cold. Species numerous; found in all 
seas, some of them being the largest of all animals. The nearest 
relationships of the whales are perhaps with the seals, among living 
forms, but the differentiation is now very wide. Of the numerous 
species occasionally straying to our coasts, the following seem prop- 
erly to belong to our fauna. The nomenclature and analysis of 
genera is chiefly taken from True’s paper on “ Collecting specimens 
of Cetaceans,” in Rept. U. S. F. C. for 1883-1885. I have also 
made considerable use of MSS. lists of species, kindly given me 
by Mr. F. W. True, and by Professor Cope. (kjros, whale.) 
Families of Cete. 
a. Upper jaw without whalebone; spiracles coalescent into one; lower jaw 
much less thick than upper; skull unsymmetrical. (Denticete.) 
b, Upper jaw with teeth (except in the adult of one genus); eye inserted 
behind angle of mouth and not much above it; snout more or less 
sharp at tip; lower jaw with numerous (6 to 120) teeth. 
DELPHINIDA, 191. 
bb. Upper jaw toothless; eve decidedly above angle of mouth. 
c. Lower jaw with 2 to 4 teeth, or saanaes toothless; snout more or less 
BNA HE AEAGUS hs) 8) fete col’ ce - « e « AZrpuipaz, 192. 
cc. Lower jaw with 18 to 50 teeth; inbut Kot sharp, sometimes truncate 
Ae tile eis hk eh ¢ el ad te deta | PHYSETHRIDAG 195. 
aa. Upper jaw with long stripe of baleen or whalebone; no teeth; spiracles 
separate; eye very small, close to angle of mouth, between mouth and 
pectorals; lower jaw very thick and deep, nearly as deep as upper, the 
cleft of mouth curved. (Jysticete.) . . . . . BAL&NIDAs, 194. 
