Summary. 



In the summer of 1915 a quantity of the bark-beetles of the 

 genus Scolytoplatypus В 1 a n d f о r d was collected, by B. Berger, in 

 the environs of Vladivostok. The beetles bore- their alleries in the wood 

 of Acer mono Maxim, and Acer mandschuricum Maxim.; the general 

 shape' of their work is very similar to that of the genus Xyloterus. The 

 species could not be identified definiti vely; it very much resembles the 

 6". iycon В 1 a n d f о r d, but does not agree completely with the drawing 

 given by its aiuhor. Moreover, the galleries of our species ramify in the 

 wood, which is not the case with S 1 . tycon. Possibly it is a new species 

 which may be designated for the present as Scolytoplatypus ussurien- 

 sis, sp. n. 



The female of the beetle in question has in the middle of the 

 pronotum a small round pit which has proved to be an orifice of a pe- 

 culiar cutaneous gland. This gland performs an ectodermic invagination, 

 the walls and bottom of which are formed of a chitinous network, whose 

 meshes are covered with a thin structureless membrane. Thus |the whole 

 gland is facetted, the network forming the margins of the facets. The 

 bottom of the gland is convex and supports a number of hollow pil- 

 lars whose walls is also facetted and summits terminated with a hair. 

 The external orifice of the gland is also surrounded with ramified hairs. 

 Under the chitinous network of the gland a layer of hypodermic cells 

 is situated, which continues immediately on the borders of the gland 

 into the hypoderm of the bodywall. A cell of this hypodermic epithe- 

 lium corresponds to each facet of the above mentioned pillars. 



The secretion of this gland seems to be oleous and to sweat 

 t hrough the membrane of the facets like the oil through the paper. 



The function of this gland is unknown, but it stands probably 

 in connection with the sexual act. 



Explanation of figures. 



Fig. 1. Scheme of the general structure of the galleries of Scolytoplatypus 

 ussuriensis, sp. n. 



Ffg. 2. Ramification of the female gallery in a rather thick trunk. 



Fig. 3. Female gallery in a thin trunk. 



Fig. 4. General view of the prothoracal gland of the female of Scolytopla- 

 typus ussuriensis, sp. n. from above. Much enlarged. 



Fig. 5. Scheme of structure of the gland; ch — chitinous network of the 

 hypoderm, hy — hypodermic epithelium, p — lateral wall of the gland 

 / — its bottom, col — pillars raising from the bottom, cp — hairs in 

 their summits, cp' — hairs on the border of the orifice. 



Fig. 6. Some pillars of the gland; n — nuclei of the cells, fc — facets; 

 other letters as on fig. 5. Much enlarged. 



Fig'. 7. Scheme of structure of a pillar; fc — facets, hy — hypodermic epi- 

 thelium, cp — hair. 



Русск. Энтом. Обозр. XVI. 1916. № 1—2. 



