334 



rely wholly (Siphonophora) or partially (Stemmiulus) free, but never 

 so distinct as in the Limacomorpha or Oniscomorpha and almost always 

 completely indistinguishable from the terga. The pedal laminae (tra- 

 cheal plates) in the form of two unpaired sternal sclerites, to which 

 the legs are directly articulated. Some of the segments (excepting 

 always the anterior 4 and the last) are very generally furnished with 

 a pair of foramina repugnatoria ; when absent these apertures are 

 sometimes represented on each segment by large isolated setae (Chor- 

 deumoidea); sometimes the whole segment is covered with hairs 

 (Cryptodesmus). 



Either one pair or both pairs of legs of the 7 th segment are modi- 

 fied in the cT to act as copulatory organs. 



My opinions as to the affinities of the families of the Helmintho- 

 morpha have undergone some change since the publication of my 

 paper upon the Classification of the Diplopoda. I recognise for instance 

 that it is impossible to regard the Polyzonidae as degenerate lulidae; 

 consequently I adopt Brandt's name Colobognatha for a suborder to 

 contain the Polyzonidae, Siphonophoridae etc. The Chordeumidae , too, 

 have been removed from the Iuloidea, and have been raised to the 

 rank of a suborder by my friends Messrs. Cook and Collins. There 

 are thus 4 suborders for the Helminthomorpha namely Colobognatha, 

 Chordeumoidea , Polydesmoidea and Iuloidea. Since sending this paper 

 to press in Dec. 1893, I have seen Mr. Bollman's posthumous article 

 on the classification of the Myriopoda. Bull. U. S. Nat. Mus. n° 46, 

 p. 153 etc. I consider that Mr. Bollman has done much to systema- 

 tise our knowledge of these difficult animals by his praiseworthy attempt 

 to remodel their classification. But although I think that most of his 

 innovations are steps in the right direction, yet there are so many 

 points of detail in which I can not agree with him that I have deci- 

 ded to allow the classification proposed above to stand unchanged 

 until an opportunity occurs of reexamining the whole question. 



Suborder colobognatha, Brandt. 



Oken's Isis, p. 704 (1834). 



Body elongate, composed of from about 30 to over 70 segments 

 and capable of being spirally coiled. 

 Head generally small and often tucked under the 1 st segment. Eyes 



