528 Mr. D. Sharp and Mr. F. Muir on the Comparative 
Family AGLYCYDERIDAE. 
Forms examined: <Aglycyderes setifer Woll. Canary 
Islands. A. wollastont Sharp, New Zealand. 
Pigs 19) Pl xa. 
A, setifer (Pl. LXII fig. 119). 
Median lobe tubular, slightly curved and twisted; median 
orifice at tip, the edge membranous without demarcation between it 
and base of internal sac; median foramen at base, the lateral 
edges being produced into two median struts (ms). 'Tegmen forming 
ring round median lobe, the dorsal part being in form of a large, 
nearly parallel-sided cap, blunt at apex; on the ventral face the 
ring is produced into a single terminal strut (tg). Internal sac 
short and with what appears to be a spine on its base (q). 
In A. wollastoni the median lobe is shorter and stouter, the 
median orifice forming a narrow horizontal slit across apex. The 
tegmen is more slender at the base of the cap and the ring and 
ventral strut curved. 
Family PROTERHINIDAE. 
Forms examined: Proterhinus validus, P. ferrugineus, 
and P. gigas, Hawaiian Islands. 
Fig. 120 Pl. LXII. 
P. validus (Pl. LXII fig. 120). 
Median lobe tubular and very slightly curved, the membrane 
at the median orifice extending basally nearly dividing the chitinous 
part into a dorsal and a ventral sclerite, the edges of the orifice pro- 
duced into a dorsal and a ventral point, the ventral one being the 
longer and curved ; median foramen at base, the lateral edges 
prolonged into two long median struts (ms). Tegmen forming a 
ring round the median lobe, the dorsal cap being large, nearly 
parallel-sided and blunt at apex. Internal sac small. 
P. ferrugineus is similar to P. validus, but the ventral edge of the 
median orifice is produced into a longer and narrower point. 
The families Proterhinidae and Aglycyderidae are hard 
to separate. In both cases there are only three joints to 
the tarsi, the third one having a small piece constricted 
off at the base, but it is not a true joint. The “beak” in 
the female Proterhinus varies in the different species and 
