75 



Hypostoma. Exterior malae as usual, not peduuculate; interior 

 malae small, rounded. Lingua long. 



Peritrema extends till before the implantation of the 1 st. leg. 

 Habitat: Geotrupes sylvaticus. 

 Patria: Netherlands. 



3. Parasitus vespillouum Oudins. 



(With Plate V, fig. 4). 



The aniraal described by me in the Tijdschr. voorEutom.v. 45, 

 p. 33, was a deutonympha. I am now in the opportuuity to des- 

 cribe the tritouympha, which can be done in a few words. 



The colour is pale yellow. 



The length 900 )*.. 



Dorsal and ventral side perfectly like that of the deutonympha. 



Epistoma tridentate ; the cusps almost equal in length ; the 

 central cusp yet somewhat longer; the lateral ones bear on their 

 outside a rudiment of a tooth halfway. (Fig. 4). 



Habitat : Geotrupes sylvaticus. 



Patria : Netherlands. 



4. Parasitus emarginatus C. L. Koch. 



(With Plate V, fig. 5-14). 



Koch has described and figured (Deu. Cr. Myr. Ar. 24; 17) 

 an Acarus which he called Ga7nasus emarginatus, because the 

 auimal's posterior dorsal shield appeared truncated posteriorly. 

 Berlese has given a rough sketch of the same animal (Ac. Myr. 

 Scorp. Ital. 69 ; 4, fig. 5 — 6) with the same character. On a 

 mole I found the aniraal and saw the same truncated shield. The 

 animal is a uympha. Adults hitherto are unknown. 



In a material gathered by Mr. S. A. Poppe in a raole's nest, 

 I found two males, one yellow and tolerably transparent; most 

 probably it had just thrown off its nymphal skin; the other 

 reddish black, most probably by its having fed on Haemogamasus 

 hirsutus. This induced me to study the nymph and to give better 



