ONYCHOPHORA OF WEST AUSTRALIA. 371 



orange papillae. Each ring here lears larger and more separated 

 papilla? which are quite white. They seem to correspond to the 

 wliite areas round papilla? of the dorsal sui'face. 



In both varieties an extremely fine light median line runs the 

 length of the dorsal sui'face. It may not appear so in all 

 specimens at a first ghmce. This, however, is due to the fact 

 that in the light brown specimens, where it seems cleai-, it runs 

 down the mifldle of a narrow band somewhat paler in colour than 

 the rest of the dorsal surface and rather free from papillse. In 

 the dark specimens, on the other hand, this narrow band is 

 da,rker than the rest of the dorsal surface, and with the naked 

 eye or low power may be all tliat is observed. A liigher magni- 

 fication will show that a, very fine light line runs through it 

 medial]}^, as in the light-coloured specimens. 



The longifcuilinal band of the doi'sal surface referred to above 

 is related to a slight depression, the fine white line being an 

 extremely narrow groove. The narrow band was noted by 

 Bouvier, but the fine median white line escaped his notice. 



In both varieties there are always a number of clea,r white 

 papilla? between the successive legs at about the ventral margin 

 of the flanks. These correspond, however, to the large papilla^ 

 of the dorsal surface and have merely lost the black pigment — 

 they are identical Avith the large clear papillpe of the ventral 

 surface. 



The skin is thrown into a, number of folds or ridges, as is usual 

 in Peripatus. There are about 14 of these between two similar 

 points opposite two successive legs. The I'idges are to be seen 

 both dorsally and ventrally, but ai'e not continuous round the 

 entire cii-cumference of the body, for they are interrupted in the 

 middle of the dorsal surface by the longitudii3al line. But for 

 this, however, some are continuous. Others arise between these 

 larger folds and do not run so far. Naturally those opposite the 

 legs are not continuous on to the ventral surface. The folds a.re 

 not all of the same width, but it can hardly be said that they aie 

 alternately wide and narrow in either variety. There is really 

 very little difi'erence. 



Orat. Papilla. 



The oral papillfe are to be found in their usual position — there 

 is nothing of particular interest to add with regairl to them. 



On many occasions slime was shot out from the openings of 

 slime glands on these oral papilla? when the specimens were 

 touched. It was emitted in large quantities when the animals 

 were dropped on to water containing a. little formalin, and also 

 when the specimens were narcotised with chloroform. 



The Cephalic Region. 



Bouvier (3) h.as described in considerable detail the rings or 

 rido-es of the integument at the bases of the antennae and in the 

 Proc. Zool. Soc.— 1920, No. XXY. 2n 



