KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 7. 209 



length of the six first pereeonal segments together. The antennal groove commences above 

 the middle of the front side of the head, and is higher than broad. 



The eyes occupy the whole surface of the head. 



The first pair of antennce (PL X, fig. 41 and 42) are about as long as the head, the 

 perseon, and the pleon together. The first joint of the peduncle is large, stout, and cylin- 

 drical, and more than three times as long as the two following; the second joint is more than 

 three times as long as the third, which is for a large part concealed under the second. The 

 first joint of the flagellum is about as long as the whole peduncle, evenly tapering towards 

 the apex, and having the inner and under sides bulging, and densely set with long olfact- 

 ory hairs; the lower front corner projects into a short cylindrical process, which is tipped 

 with two strongly developed olfactory hairs; the upper margin of the joint is straight, 

 and provided with two or three equidistant pairs of short hairs. The second flagellar 

 joint is unusually well developed, longer than a third of the first joint, and much 

 broader than the following flagellar joints; on the lower side near to the apex projects 

 a cylindrical process, similar to that of the first joint, and tipped with two similar hairs. 

 The following joints are cylindrical, subequal in length, and about five times as long as 

 broad; each joint is set with two minute hairs on the upper side. The flagellar joints 

 are in all twenty-four in number. 



The second pair of antennas (PI. X, fig. 43) are only a little longer than the first. 

 The first free joint of the peduncle is somewhat broader than long, the second is shorter, 

 the third longer, but not fully as long as the two preceding joints together. The first 

 joint of the flagellum is considerably longer than the last peduncular joint, but much 

 narrower, cylindrical, and fully six times as long as broad ; the following are subequal in 

 length, only a little shorter than the first, and nearly six times as long as broad; the 

 flagellar joints are twenty-six in number. 



The labium is much longer than broad, deeply bilobed. 



The mandibles have a very large molar tubercle; the incisive lamina is short, with 

 six rounded, sharp teeth. The first joint of the palp is short and stout; the second and 

 third are longer, and equal in length; the third is fringed with minute hairs. 



The first pair of maxillce. The apex of the secondary lamina is armed with four 

 strong spines. 



The second pair of maxillae. The secondary lamina is very broad, and more than 

 three times as long as the principal lamina. 



The maxillipeds. The basal portion is comparatively narrow; the lateral lamina: 

 are elongate, fringed with hairs along the inner margins, and about as long as the basal 

 portion; the median lobe is strongly bent inwards. 



The perceon. The first two coalesced segments are a little shorter than the third 

 and fourth together, and are also shorter than the seventh segment, which is the lon- 

 gest of all. 



The epimerals are somewhat shorter than the under margins of the corresponding 

 segments; those of the first four pairs are about as deep as long; those of the last three 



are longer than deep. 



27 



K. Sv. Vet. Akad. Handl. Band. 22. N:o 7. 



