286 Mr. R. I. Pocock on the 



It is difficult to reconcile the acquaintance that Wood must 

 have had with Platydesmus (redescribed as Brachycyhe) with 

 his failure fully to appreciate the relationship existing between 

 the families constituting his suborder Strongylia and the 

 family Polyzonidse, to which he rightly considered this genus 

 to belong. This failure led him to raise the group of suctorial 

 Myriopods to the rank of a suborder, equal in value to the 

 Pentazonia or Strongylia ; to this suborder he gave Brandt's 

 name Sugentia. 



By M.de Saussure the Polyzonidee, containing Platydesmus ^ 

 were regarded as allied most nearly to the lulida?, and were 

 treated simply as a family of the Chilognatha. 



Yet Dr. Latzel, in 1884, gave to the Polyzonidse Brandt's 

 name Colobognatha, and made this group co-ordinate with 

 the Chilognatha, comprising the Glomeridge, lulidas, &c., thus 

 clearly showing that, in his opinion, the relationship between 

 the Glomeridse and lulidge is greater than the relationship 

 between the Polyzonidse and the lulidse. 



That a naturalist so careful and observant as his elaborate 

 work on the Austro-Hungarian Myriopoda has shown him 

 to be, should hold these views it is hard to believe, for all the 

 points given above as characteristic of Iidus are equally 

 characteristic of Polyzonium, and the only important respect 

 in which the latter genus differs from the former is the pos- 

 session of a suctorial proboscis instead of manducatory jaws. 



If no intermediate form had been known, and if Dr. 

 Latzel had only been acquainted with Siijhonophora, the most 

 aberrant genus of the group, the views expressed in his clas- 

 sification would even then have been unintelligible ; but being 

 familiar, at all events from descriptions and figures, with 

 Platydesmus^ and seeing from the modifications of its mouth- 

 parts the method by which the proboscis might have been 

 formed, it is astonishing that he should have committed him- 

 self to the restoration of the group of Diplopoda with suctorial 

 mouths as opposed to the group of DipJopoda with masticatory 

 mouths. 



The distinguishing features of Polyzonium are as follows : 

 — The head is pointed in front ; the mandibles are reduced in 

 size ; the gnathochilarium is represented by a plate pointed 

 anteriorly and laterally soldered to the sides of the head, thus 

 forming the proboscis. 



In the allied genus Platydesmus the head is more or lesa 

 pointed in front, the mandibles are reduced, but the gnatho- 

 chilarium is distinct, and not laterally soldered to the head, 

 so that there is only a partially formed proboscis. 



If these characters be compared with those of Glomeris^ 



