436 CALIFORNIA ACADEMY OF SCIENCES. 



line of the prong at an increasing angle from in front 

 backwards. The forks are less chitinized in young speci- 

 mens, but very pale colored ones have them comparatively 

 strongly chitinous, so that they appear very dark, while 

 the rest of the outer parts are white. 



The ligula is a short sclerite, divided into glossee and 

 paraglossce. The glossse are two rounded lobes, with a 

 shallow concavity between them. They bear a few short 

 hairs. External to the glossae are the paraglossae which 

 are also two small simple lobes. They are separated 

 from the glossae a little more deeply than the latter are 

 from each other, and like them are covered by a few small 

 hairs. 



The submentum is a simple sclerite back of the mentum, 

 and mostly concealed by the forks and connecting fold 

 from the latter. 



The maxillce (plate lx, fig. 8) are very weak, unchit- 

 inized structures, lying entirely within the mouth cavity, 

 and concealed by the other mouth-parts on account of 

 their very reduced size. Each consists of a basal un- 

 divided portion, somewhat roughly triangular in outline, 

 and of two distal, soft fleshy lobes. The outer lobe is 

 the larger of the two, and its inner edge lies ventral to 

 the outer edge of the smaller lobe. Both lobes are longer 

 than wide. There are no hooks or points of any nature, 

 and no hard chitinous parts. The lobes appear to be" 

 galea and lacinia, but in the adult form there is nothing 

 to show that these are what they are, and that they are 

 not simply the result of a secondary division of a simple 

 fleshy lobe, which is the common form of maxilla in the 

 group. The basal portion shows no indication of being 

 composed of two sclerites. The rudimentary condition 

 and soft weak structure of the maxillse apparently must 

 render them of little or no function. 



