THE MYRIAPODA OF NORTH AMERICA. 137 



ISlO.PetaserpeD Cope. Trans. Amer. Ent. Soc., 65 (rosulbm). 

 1880. //!>M(/<8ow Fauzago. Bull. Soc. Eiit. Ital., 276 (paUidum). 

 IXXI.Hexagkna McNeill. Proc. U. S.Nat. Mus., 328 (crijptocepliala^romlbum). 



From the above synonymy it can be seen that I have united the 

 American genera Petaserpes and Hexaylena with the European genus 

 Polyzonium. 



Concerning Petaserpes I wish to call attention to the following sen- 

 tence in Dr. Cope's diagnosis: "Anuuhe without lateral processes, each 

 with two pores, forming two rows on each side of the body." 



The lirst part implies that each aniiula has two pores, but his next 

 phrase that each has/owr instead of two. 



This obscurity of statement led Mr. McNeill to form his Hemglena, 

 which has only one row of foramina repugnatoria on each side of the 

 body, as was no doubt the case in Dr. Cope's specimens. 



5. OCTOGLENA. 



186*1. Octoylcna Wood. Proc. Phila. Acad. Nat. Sci., 186 (birirgata). 



I have never seen a specimen belonging to this genus, but as it is 

 somewhat of a stumbling block, I call attention to the following points: 



Judging from Dr. Wood's figures and some remarks by Dr. Cope, it 

 seems to me that Oeioylena is closely related to Polyzonium, but that it 

 differs in having the first dorsal plate not produced to the base of the 

 autenme, and the body much narrower than in Polyzonium. 



6. PLATYDKSMUS. 



1843. Plalydesmns Lucas. Ann. Soc. Ent. France, 51 (poh/desmoides). 

 1849. Pic8todeninu8 Lucas. Rev. et. Mag. Zool., 589 (moreleti). 

 1864. ^mc/u/ci/fce Wood. Proc. Phil. Acad. Nat. Sci., 187 (leconfei). 



The above nominal genera seem to agree in the shape of body, mark- 

 ings of segments, and structure of mouth parts, while the number of 

 ocelli varies. Platydesmus has one, Piestodesmus has two, and Brachy- 

 cybe has none, but until all these points can be verified it is not safe to 

 form subgeuera on this character. 



7. STKMMIULUS. 



1844. Stemmiiilits Gervais. Ann. Soc. Ent. France, 28 (biociilatus). 

 1881. Slcmmijulus Karsch. Neue Jul. Her. Mus., als Prod. Jul. Monograph., n 

 (emend.). 



This genus has been ranked by Dr. Latzel as only a subgenus of 

 JM/MS, but on account of the peculiar number of ocelli I believe it ought 

 to be given a full generic rank, at least until more can be ascertained 

 about the structure of the mouth parts. 



The original orthography of Gervais should be employed. 



