Se Nea Na Po eke META SRSA SOAS See Mees SUNT SS SATE ee ey DTT Tle ee See BR cer eg te 
1884.] Zoology. 433 
lant on the measurement of the force displayed by the adductors 
of bivalves, he refers at some length to those of A. Coutance, 
made especially on the Pecten maximus. 
Plateau then describes at length his own interesting experi- 
ments, from which he draws the following conclusions : 
he only way to carefully compare the muscular force of 
lamellibranch mollusks with that of the higher animals consists 
inestimating the absolute forces of the muscles by the square 
centimeter of transverse section. 
2. The result of this comparison shows that the absolute 
force of the adductor muscles of Lamellibranchs is analogous 
to the absolute force of the muscles of vertebrates. The reader 
will probably make the remark that the fibers of the ad- 
ductor muscles of the bivalves are generally smooth, while, the 
muscles of animal life of vertebrates are composed of striated 
fibers. The, objection is a serious one; but with the result to 
place me in the best possible condition, since I have undertaken 
some researches of the same kind on the Crustacea. The mus- 
cles of these articulates are striated, and present a texture very 
near to that of vertebrates. 
Turke New FAMILIES oF FISHES ADDED TO THE DEEP-SEA 
FAUNA IN A Year—In addition to the family of Eurypharyngids, 
fully described lately by Mr. Ryder and myself, two new family 
types were added to the deep-sea fauna by the explorations of the 
pa Fish Commission on steamer Albatross in 1883. These will 
called Derichthyidæ and Stephanoberycidæ. 
The Derichthyids are represented by one specimen, which has 
an eel-like form, a serpentiform head, with well developed maxil- 
pi as well as palatines, both bearing bands of teeth, a well de- 
neck, and the scapular arches remote from the skull. The 
: e ote 
inal or sub 
ce iimerous spinous rays in the procurrent upper and lower 
sping? a Cavernous head, toothless palate, and scales with 
Fray faces. It includes my Stephanoberyx mong and Acan- 
rays, th lithe nit; the latter has abdominal yentrals and branched 
.7*, thus differing from Stephanoberyx, but it is not absolutely 
preg d on a small specimen. i 
“er interesting fish, from the same collection, is an Ale- 
n aid, with the body as well as head scaleless, which I shall 
aS Aleposomus copet.— Theodore Gill. 7 
XVITI.—no_ ry, 
- ee it may prove to be merely the mature form of the 
