104 



REPORT UPON A COLLECTION OF 



a small gland prominence, beyond the second pair a large spine, followed 

 by a large gland spine, a prominence that perhaps represents the third 

 lobe, a spine, a large gland spine, and at wide intervals two more spines 

 followed by a single gland spine. The lobes and the margin, including 

 the mouths of the submarginal pores, are very heavily chitinized. Mar- 

 ginal ducts quite short and stout, somewhat larger than those of the 



Fig. 24. Pseudodiaspis magna n. sp. : pygidium of adult. 



dorsum which are numerous and arranged in irregular rows as indi- 

 cated in the figure. Microducts, opening at the apices of the gland 

 spines, numerous, long and slender, the apices of the ducts of the type 

 indicated in Fig. 2 1C. Anal opening small, placed well toward the apex 

 of the pygidium. Ventral side apparently without tubular ducts. Cir- 

 cumgenital pores lacking. 



Second stage with the pygidium (Fig. 25) with the lobes as in the 

 adult but with practically no dorsal ducts. 



First stage, with the antennae (Fig. 23D) 6-segmented, the terminal 

 segment neither elongate nor annulate, the third segment noticeably 

 long; pygidium (Fig. 23B) with a pair of large, toothed lobes and be- 

 tween these a pair of very small simple lobes. 



Notes: This species is evidently quite close to P. dentilobis Ckll., the 

 description of which follows, but it is apparently distinct. The two species differ 

 chiefly in the form of the lobes (compare Fig. 26B and 26C) the lobes in denti- 

 lobis being distinctly truncate while in magna they are acute. Also the marginal 

 ducts of dentilobis are noticeably longer and more slender. 



