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



distal half flattened on the dorsal aspect and bearing three keels, a 

 median and a pair of lateral ; the ventral edge of the median 

 orifice coming to a small point but not projecting far beyond the 

 dorsal edge ; slightly constricted about middle ; median foramen 

 occupying the ventral aspect of the basal half. Tegmen in form of 

 a shield-shaped sclerite, with the corners not meeting on the dorsal 

 face, and no trace of prolonged cap. Internal sac small with complex 

 armature consisting of a long chitinous flagellum (a) and a pair of 

 strong, curved, chitinous spines (6). Stenazygos not investigated, 



Lachnaea palmeda. 



In this species the median lobe is well developed, curved near the 

 apex, but straight beyond. The armature on sac consists of a small 

 spine-like flagellum and a pair of large spines, with a complex 

 process closing the median orifice consisting of a plate bearing a 

 median curved tongue and a pair of lateral, rounded plates. The 

 tegmen is Y-shaped, the strut being slender and bifurcate at end. 



Saxinis saucia. 



Median lobe very slightly curved, with the ventral edge of median 

 orifice pointed and extending slightly beyond dorsal edge ; the 

 median orifice closed by the armature on the sac. Median foramen 

 occupying the ventral portion of basal half. Tegmen V-shaped. 



Cry otocephalus aureolus. 



Median lobe well developed and chitinised, the distal half being 

 considerably flattened ; the ventral edge of medium orifice drawn 

 out to a fine, flattened point, with the tip curved downward, pro- 

 jecting much beyond the dorsal edge ; median foramen occupying 

 the whole of the ventral side of the basal half. Tegmen shield- 

 shaped, with a keel along the middle of the inner side. Armature 

 on sac not examined. 



Cryptocephalus astiiriensis ? 



Of the same type as G. avreolus, but the ventral edge of the median 

 orifice drawn out into a blunt point and not turned downward. 

 Armature on sac complex, that at the base closing the median for- 

 amen ; at the apex there are two broad, bifurcated spines and a 

 flattened median sclerite, but no flagellum. 



Eumolpus surinamensis (PI, LXXIII figs. 207, 207a,). 



The apical third of the median lobe strongly curved and slightly 

 flattened, the ventral edge of the median orifice pointed and pro- 

 jecting far beyond the dorsal edge, the basal two-thirds consisting 



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