230 | Ca: S Raita S [Mareh 
differ from the Arachnids in the absence of all mouth parts,” 
in the proctodeal excretory tubes, the simple nervous system, 
smooth muscular tissue, and in the absence of nephridia, and 
they further differ from not only the Arachnids, but from all 
Arthropods in the fact that the gonads open into the hind-gut. 
V—MALacopopa.” 
The Arthropodan features of the Malacopoda, represented by 
the single genus Peripatus, are the trachee, the legs terminat- 
ing in claws, the appendicular nature of the jaws, the exclu- 
sive use of a pair of nephridia for genital ducts, the reduced 
coelom; the several ostia of the heart, the heart being enclosed 
in a pericardium; the lacunar circulation. On the. other 
hand, the Malacopoda differ from all other Arthropoda and 
agree with the Annelids in the following particulars: 
The presence of functional nephridia in each body segment; 
the presence of well-developed coxal glands; the existence of 
an outer circular muscular layer in the body wall; the ab- 
sence of striation from all muscles except those of the mouth 
parts; the presence of cilia in the alimentary canal and in the 
nephridia; the situation of the antenne as outgrowths from 
the primitively preoral region; the muscular nature of the 
pharynx, unlike that of any Arthropod and strikingly that of 
certain Cheetopods. The eyes are too unlike the usual organs 
of any other Arthropod, but, as figured by Balfour, they closely 
resemble these organs in Autolytus. There is, too, an a es 
of a well-developed external cuticular skeleton, S0 that the 
absence of a true jointing in the appendages is noga 
Judging from figures, the terminal claws of the legs might 
compared with the setæ of the annelid parapodium. : 
On the whole, Peripatus cannot be placed beyond qoum 
in the Arthropodan phylum, and it is doubtful if it W 
have been placed there were it not for the presence of trache®: 
1? The internal acicular teeth as appendages. =, 
18] prefer to use the nab NN Areal ass nip the oldest, beng 
given by Blanchard in 1847. Onychophora of Grube dates from 1853, °™ ts of 
was given by Mosely in 1874, The failure of Blanchard to recognize all points 
structure does not invalidate his name. 
