147 



A series of cross sections was made of the stalk below the ovarian 

 cavity to ascertain whether it had been burrowed by this or any other 

 larva, witb the result that the plant tissue below this point was found 

 to be intact. 



So far as appearances go, then, this Chalcidid is phytophagous rather 

 than parasitic, yet from the perfect uniformity of habit in the sub- 

 family to which it belongs this state of 

 affairs is almost incredible. We must leave 

 it for future field observations upon this 

 species or upon some congeneric species to^ 

 definitely settle this most interesting point. 



Not alone from its habits, but also from 

 its structure, is this insect of great interest. 

 It is closely related to the abnormal and 

 long-misunderstood genus Tetracnemus of 

 Westwood, originally described in the Mag- 



• ^ ^-c -K'^i. .,^7 TJ^r.*^^.. -P^-^ lOQT -r^r.^.^ o ^c Q Fig. 21.— Tetracnemusdiversicornig. male, 

 azine of ^ atural History for 183 i , page 2o8, enlarged (redrawn from Westwood). 



from the male sex only, and from a specimen captured upon oak in 

 Coombe woods, in July, 1835. We reproduce here Westwood's figure of 

 this abnormal insect, and it will be seen from the ramose antennae that 

 it closely resembles certain members of the subfamily Eulophince, 

 Walker in fact placed Tetracnemus in this latter subfamily, consid- 

 ering that Westwood had miscounted the tarsal joints in his species. 

 Ashmead, however, on the strength of a species captured in Florida, 

 has confirmed (Proc. Entom. Soc, Washington, i, 203) the accuracy of 

 Westwood's conclusion, as does also the form which we are about to de- 

 scribe, in so far as it shows that there are Encyrtinse with branched 

 antennae. Up to the present time, then, the only members of this great 

 subfamily having this striking i^eculiarity are Westwood's Tetracnemus 

 diversicornis, the undescribed species mentioned by Ashmead and the 

 insect we are now treating, the latter possessing particular interest from 

 the fact that we have the female sex, which is not known in Tetracnemus. 



TANAOSTIGMA* gen. nov. 



JfaZe.— Resembles someNvhat closely Tetracnemus Westwood. Antennae 11-jointed-f- 

 2 ring-joints; scape with a slight expansion below, the expansion faintly serrate; 

 pedicel one-third as long as scape, narrowed at base; joints 1, 2, 3, and 4 of the funi- 

 cle (not counting ring-joints) each with a single long hairy dorsal apical ramus, each 

 ramus bent forward and reaching to base of club ; joints 1 and 2 short, subequal in 

 length, and considerably broader than long; joint 3 one-third longer than 2 ; joint 4 

 rather more than twice as long at 3 ; joint 5 rather more than three times as'lony as 4, grad- 

 ually xvidening toicards tip; joint 6 a little longer than 4, gradually widening from 5; 

 club oval, somewhat flattened, twice as long as joint 6 of the funicle and slightly 

 wider, joints plain. Face sunken in and shriveled in death: ocelli forming a straight 

 line. Mesocutum tcith a faint transverse, slightly oblique impressed line just anterior to 



* Greek, Tdvab?-\-criyj2rf. 



