374 



PROF. AY. J. DAKIN OTV THE 



It will beiioti(ted tliat tliere is a very large aiiioiiiit of variation. 

 Bouvier found, however, tliat in many caees the papillae conld 

 be discovered by a study of the anatomy. He concluded that 

 there was reason to l>elieve that Per^ipatoides woodivarcU possessed 

 crural papilla^ for all the legs witli perhaps the Exception of the 

 last tuo pairs^ although further investigation might show them 

 to exist there too. 



In making a. comparison with other Australian species of 

 Peripafoides, Bouvier states (relying on Fletcher's desci iption of 

 P. occidentcdis (7)) tliat our northern variety differs from all 

 other Australian forms in the possession of crural papUlce on the 

 1st pair of legs. In fact, this is stated to distinguish P. woodwardi 

 from all other known species of Peripatus. This statement 

 renders an examination of the soutliern variety particularly 

 interesting. 



Let us first take Bouvier's northern type. We have found 

 that the mere presence or absence of crural papiltge when examined 

 externally means almost nothing. Sections show alivays that the 

 papilla? are present on certain legs but th.at they may lie eitlier 

 invaginated (see PI. III. fig. 4, Crur. pap.) or protruded. Every 

 specimen examined has had diflerent crural papillte protruded. 

 It may either depend upon the fixative or the animal may pro- 

 trude certain papilla? at definite times. The preserved specimens 

 woukl then indicate the condition at the time of fixation. 



The fact remains, however, that crural glands are present in 

 the male in every leg (PI. I. fig. 3, Ci-.Gl.), and papilla? are to 

 be found on all of them too. This is a correction to Bouvier's 

 otherwise excellent description, for he is not certain of their 

 presence on the penultimate pair. They are rudimentary on this 

 pair, corresponding to the condition of the crural gland, which 

 is very small in these legs (see PI. I. fig, 3). The papilla is 

 well developed on the last legs, and its place is marked even 

 when withdrawn by a minute aperture wn'th raised lips. 



It is striking to find that the above description will answer 

 exactly for the southern form (P. occidentalis) . Males have been 

 obtained with almost all the appendages showing protruded crural 

 papillae. Sections indicate the presence of crural glands and 

 crural papilla? exactly as they are found in the Mundaring 

 specimens. We must emphasise in this connection the necessity 

 for the external examination of many specimens before one can 

 state how many crural papillse are present. Thus we now have 

 two varieties (of one species) which are characterised by the 

 possession of crural papillae on the 1st pair of limbs.* 



* Tlie above puts out of court Fletcliei-'s description of P. occidentalis in wliicli 

 he states that the males have white papillse on most of the legs, hut not on those of 

 the \st pair. 



