366 PROFESSOR E, RAY LANKESTER. 
two distal together represent the basipodite of the typical 
Decapod limb. 
The homologies thus arrived at do not agree with those 
put forward by Professor Huxley in his ‘ Anatomy of Inver- 
tebrated Animals,’ 1877, p. 281, since he identifies the fla- 
bellum of the Apus limb with the exopodite of Decapods, 
and regards the bract of Apus as representing the epipodite. 
Further, he considers a part of the corm or protopodite of 
the first thoracic foot of Apus as the endopodite, and the 
endites as merely secondary processes. 
The careful examination, however, of the structure of the 
appendages of Apus leads, I think, when combined with the 
examination of the numerous modifications of the oral 
appendages of Decapoda, which recent writers have minutely 
described, to the conclusions which I have advanced above. 
There are some further points of interest arising from the 
comparison of the walking and swimming feet of Malacostraca 
with the abdominal feet of Apus. 
In those Decapoda in which, at an early period of their 
development, the maxillipedes and even the representatives 
of the ambulatory appendages resemble in form the bira- 
mose Nauplius limb (Sergestes, Penzeus, and Schizopods) we 
obtain data for identifying the exopodite of the antenna 
with the exopodite of the postoral series, and similarly for 
identification of the endopodites. And thus by referring 
again to the Nauplius antenna of Apus and the assumed homo- 
logies of its part with the foliaceous limbs of the truncal 
region of that animal, we arrive by another method than that 
adopted when the comparison of the second maxilla of Deca- 
pods with the abdominal feet of Apus is made the starting 
point, at an identica] determination of the homologies of the 
parts. The persistent ramus of the ambulatory limb of the 
Decapoda is the fifth endite of the Apus limb, its coxopodite 
and basipodite are the corm of the Apus limb, the sixth endite 
is suppressed as it so nearly is in the first thoracic foot of 
Apus—the epipodite is the flabellum, and the branchial 
plume, where present, probably represents the bract of the 
Phyllopod’s appendage. 
The relations of the thoracic swimming feet of Nebalia, 
and the abdominal swimming feet of Palinurus to the Apus 
limb—as they appear to me—are indicated by the letters 
affixed to those swimming feet in the woodcut (XJV and X). 
A remarkably close agreement in form is seen when the 
first maxillipede of Callianassa (J/J) is compared with the 
lamelliform foot of Nebalia (XJV). But upon studying a 
series of first maxillipedes it becomes probable that the 
