No doubt a slip of the pen for Monotremata.
"More Letters of Charles Darwin" by Charles Darwin
The Monotremata and Marsupialia have curious Y-shaped spleens.
"Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 8" by Various
The Monotremata are eminently interesting, as in several important points of structure they lead towards the class of reptiles.
"The Descent of Man and Selection in Relation to Sex, Vol. I (1st edition)" by Charles Darwin
It is much more nearly paralleled in the little group of Monotremata allied to the living Ornithorhynchus.
"Dragons of the Air" by H. G. Seeley
NIPPLES, absence of, in Monotremata, i.
"The Descent of Man and Selection in Relation to Sex" by Charles Darwin
The question is, What is the relation of these bonelets to the coracoid of the Monotremata and to the corresponding regions of reptiles?
"The Cambridge Natural History, Vol X., Mammalia" by Frank Evers Beddard