102 



REPORT UPON A COLLECTION OF 



constriction, the abdominal segments projecting but little at the margins. 

 Cephalothorax quite heavily chitinized cephalad of the mouthparts. Mar- 

 gins of the abdominal segments with at the most a few very minute gland 

 spines and with numerous small ducts. Dorsum with a submedian group 

 of small ducts on each side of each abdominal segment. 



Fig. 22. Pseudosiaspis ruelliae n. sp. : pygidium of adult and antenna of first 



stage. 



Pygidium (Fig. 22) rather acute at the apex. Median lobes quite 

 large, prominent, straight and with their apices nearly truncate. Second 

 and third pairs consisting merely of an acute prominence. Between the 

 second and third lobes are two small gland spines and beyond the third 

 lobes a series of such spines arranged singly. Dorsal ducts rather few, 

 somewhat smaller than those of the margin, the arrangement as indicated 

 in the figure. Microducts very minute and short.. Anal opening moder- 

 ately large, about one-fourth of the length of the pygidium from its apex. 

 Ventral side apparently without tubular ducts. Circumgenital pores 

 lacking. 



Second stage with the pygidium very closely resembling that of 

 the adult, differing only in having very few ducts. 



First stage larva with the antennae (Fig. 22) 6-segmented, the 

 terminal segment neither elongate nor annulate. Pygidium with a 

 single pair of very small lobes. 



Notes : I know of no species that this closely resembles. 



