No. 446.] 



PHi ) T/NL ^S MA RGLXELL US. 



material is slv)\vn to he pentetrated bv tuimeroiis tnulie;i-. The 

 vertical or oblique tr.iche^i: continue to branch i)rofusel\ ni an 

 arborescent manner. This repeated branching is charactci ist ic 

 of the trachea; of the photoj^enic tissues. The trachealcpitlu-1- 

 ium is composed of thin, flattened cells, with lar<;e liattrncd 



dant in the lumen of the lari;e tubes. These internal chitinous 

 hairs have been noted in Lampvris i)\ ( iersla'cker, and in 

 Luciola by h:mery. The lioht-or-ans are innerxaled by nerves 

 from the last two abdominal -an-lia. These ,i;an-lia are both 

 situated in the fifth se-ment. over the more cephalic li-'ht-plate. 

 I failed to trace more than these primary nerve branches, as my 

 attempts at methylene blue injection weie unsuccessful. 



Each light-plate is com[)o.sed of two distinct layers, in this 



