Manchester Memoirs, Vol. xliii. ( 1 899), No. 3. n 



Tenthredo caerulea, sp. nov. 



Caerulea; basi mandibuloriim, labro femoribusque subtus 

 albis ; alis fusco-hyalinis, fascia substigmatali fumata. $ . 



Long. 12 mm. 



Antennae not much longer than the abdomen, dis- 

 tinctly tapering towards the apex, the basal four or five 

 joints blue, tinged with purple, the apical joints black, 

 the scape closely punctured, sparsely pilose ; the flagellum 

 thickly covered with short, black hair. Head smooth, 

 shining, impunctate, the labrum white; the occiput sharply 

 margined ; the vertex roundly raised in the middle ; the 

 hinder part separated by an oblique depression from the 

 ocellar region ; the frontal area narrowed behind, the sides 

 sharply and stoutly keeled, the apex more depressed and 

 with a raised conical piece in the middle. Clypeus with 

 a raised semi-circular incision, smooth ; the labrum and 

 base of mandibles thickly covered with long, white hair ; 

 the mandibles are broadly white at the base ; the apical 

 joints of the palpi are white. The middle lobe of the 

 mesonotum is raised, with a slope from the middle to the 

 base and apex, the former being the shorter and steeper ; 

 the furrow is deep ; the apex sharply triangular ; the 

 middle lobe bears large, deep punctures, all clearly sep- 

 arated ; the lateral lobes are less distinctly punctured. 

 Scutellum pyramidal, rounded on the top ; sparsely 

 covered with large, deep punctures ; the apex with a 

 more oblique slope than the base. The base of the 

 metanotum has an obliquely rounded slope, the top of 

 which is roundly raised, the sides being more narrowly 

 roundly raised ; the apex is bluntly, triangularly raised in 

 the middle and sharply separated from the basal part of 

 the segment ; the sides are finely striated in the middle. 

 Propleurse deeply depressed in the middle, sharply keeled 

 on the base. Mesopleurae smooth at the base and apex ; 



