RELATIONS OF ANOMIA. 533 
deferentia opening into a distinct urethra. Ureters discharge directly 
into the bladder the renal secretion, which thence passes into the ure- 
centa with the mother, but attached by her to the nipple when born, from 
which the milk is forced by herself into the mouth of the young. Scro- 
tum in front of penis. 
XIII. ORDER MARSUPIALIA. 
Only order of the sub-class. Contains thirteen families, sae to 
four sub-orders: RHIZOPHAGA, with one family; SYNDACTYLI, with seven 
families, two of which are extinct; SarcormaGa, with two fa iaeoe 
CHIROPODaA with one family; also two extinct families of doubtful mnt. 
ties. : 
SUB-CLASS ORNITHODELPHIA. 
Brain with the cerebral yoppa chiefly connected by a well de- 
veloped anterior commissure, the corpus callosum being very rudimen- 
tary, and with no defined psalterial bund with the septum very mu 
reduced in size. (Flower.) Sternum with a peculiar ame sal 
(the episternum or interclavicle) in advance of the manubri ale 
rnum. oracoid extending from the clavicle to the ene Tado 
towards maturity anchylosed with the scapula. The oviducts, alad 
below into uterine pouches, but opening separately from one another, as 
in oviparous vertebrates, debouch, not into a distinct vagina, but into a 
cloacal chamber, common to the urinary and genital products, and to the 
fæces. Testes abdominal in Sethe throughout life, and the vasa defer- 
entia open into the cloaca, and not into a distinct urethral passage. Ure- 
ters pour the renal secretion, not into the bladder, which is connected with 
the upper extremity of the cloaca, but into the latter cavity itself. Mam- 
mary glands with no distinct nipples. (Huxley.) 
XIV. ORDER MONOTREMATA. 
Only order of the sub-class. Contains two families. 
On THE RELATIONS or ANomrA.— By Pror. EDWARD S. Morse. 
Tuts peculiar genus of Lamellibranch mollusks included also 
Terebratula according to the early writers on the subject. Misled 
by external characters, Linnæus, Lamarck and others believed 
these two forms closely related. While not the slightest ground 
existed for bringing them together, yet the mere fact of these two 
animals being enclosed within a limy shell composed of two pieces, 
held to the rock by a process which passed out through that ele- 
ment of the shell which was below, was sufficient proof of their 
kinship, at least to those who were ready to judge everything 
