476 Records of the Indian Museum. [Voiv. VIII, 



curiously modified type. The basal portions of these papillae are 

 round and well elevated above the general surface and their 

 apical spines, usually very fine and slender, take the form of large 

 broad scales with their apices directed forwards. The tips of 

 one row of scales overlap the bases of the row immediately in 

 front. Bach scale is flat about "25 mm. in length, lanceolate 

 in outline and finely pointed distally ; the margin is slightly 

 roughened at the base of the apical portion (pi. xxxiv, fig. 3). 

 There are very frequently two secondary annulations on the 

 ventral aspect of the antenna between those of the primary series. 

 These additional annulae, which are apparently developed in order 

 to increase the number of scales, are restricted. to the ventral surf ace 

 and do not extend round to the dorsal side (pi. xxxiv, fig. 2). 



The appearance of this scale-bearing patch is shown in pi. 

 xxxiv, fig. I, and in more detail in fig. 2, which represents a 

 portion of the antenna viewed laterally ; it constitutes one of the 

 more striking external features of T. williamsoni, for a similar 

 structure has not, I believe, been observed previously in any species 

 of Peripatus. 



The closest examination of the area at the base of the an- 

 tenna and of the row of papillae which Bouvier terms the "arceau 

 oculaire " fails to reveal any trace of the eye. I have also been 

 unable to detect the " organe frontale.'''' It seems not improbable 

 that the patch of scales on the under surface of the antenna is 

 tactile in function, compensating in some degree for the complete 

 loss of sight. 



Buccal region. 



The mouth (pi. xxxiv, fig. i) is surrounded by large whitish 

 lobes or tips. The lobes of the outer ring are sixteen in number, 

 the pairs at the anterior and posterior extremities being some- 

 times fused. Those of the four anterior pairs bear a single spinule, 

 while on those situated further back there may be one, two, or 

 more rarely three such spinules. The inner ring only exists in 

 the anterior part of the buccal opening and consists of six lobes, 

 three on each side ; the posterior pair is usually concealed by the 

 adjacent lobes of the outer ring. The anterior lobe is the largest 

 and bears three spinules, while the middle lobe has two. The 

 '^ tongue" is longitudinally ridged and bears a single row of 

 spinules. 



The jaws are similar to those of Eoperipatus. On the outer 

 blade (pi. xxxiv, fig. 4) there are two, less commonly three, 

 accessory teeth close to the main tooth. On the inner blade 

 pi. xxxiv, fig. 5) there are, apparently always, three accessory 

 teeth and a series of from eight to ten small denticles separated 

 from the accessory teeth by a short diastema. 



Oral tentacles. 



The oral tentacles or papillae are short and bear skin-papillae 

 only on the lateral portions of their distal extremities. The open- 



