528 Mr. D. Sharp and Mr. F. Muir on the Comparative 



Family AGLYCYDERIDAE. 



Forms examined : Aglycydercs setifer Woll., Canary- 

 Islands. A. wollastoni Sharp, New Zealand, 

 Fig. 119 PI. LXII. 



A. setifer (PI. 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 (a). 



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 : Proterliinus validiis, P. ferrugincus, 

 and P. gigas, Hawaiian Islands. 

 Fig. 120 PI. LXII. 



P. validus (PI. 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. fe7-ruginens is similar to P. mlidits, 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 



