168 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVIII. 



A, anal vein (postcostal vein); antenod ros up, antenodal costal space (antecubital cojttal space); 

 an ar. anal area (postco.stal space); AR, arctiliis; has r ad, basal radial space; bag sp, basal space 



(basilar space, upper basal cell or median 



space); hr. bridge; C, costa (costal vein); 

 Cii, cubitus (submedian vein); Cui, first 

 branch of Cu (first sector of the triangle); 

 Ciu, second branch of Cu (second sector 

 of the triangle); Ciu^, branch of Ctioa 

 (inferior branch of second sector of the 

 triangle) ; J/, media (upper and lower 

 sectors of the arculus); Mi, first branch 

 of Jf (apical part of principal sector-^, 

 extending from subnodus, S, to apex of 

 wing); .l/i((, long sector between M^ and 

 J/o (ultranodal nr jjostnodal sector); il/o, 

 second branch of M' (nodal sector) ; 

 Mi+2,l^ trunk from which arise the first 

 and second branches of J/ (basal part of 

 principal sector — extending from its ori- 

 gin to subnodus, S); Jfj, third branch of 

 3/ (median sector); ^f^, fourth branch of 

 Jf (short sector); ma, medioanal link; S, 

 nodus (cross vein at end of Sc, between 

 Cand B): O, oblique vein; postnod cos s}^, 

 postnodal costal space (postcubital costal 

 space); postnod rad sp, postnodal radial 

 space; quad, quadrangle (quadrilateral); 

 B, radius; R+^f, radius+media (median 

 vein); J?i, first branch of li: Rs, radial 

 sector (subnodal sector) ; ,S, subnodus; 

 ,SV, subcosta (subcostal vein); St, stigma 

 1 pterostigma) subeos sj), subcostal space; 

 siibquad, subquadrangle (median space 

 orlower basal cell); 1, antenodal of first 

 series (antecubital of first series); 2, ante- 

 nodal of second series (antecubital of 

 second series or subcostal cross vein); S, 

 postnodal (postcubital); in fig. 1 the ante- 

 nodals number about 15 and the post- 

 nodals about 17. In fig. 2 the basal radial 

 space is open — tliat is, Mi+2 beyond the 

 arculus does not approach Ji; in fig. 1 

 the basal radial space is partly closed — 

 that is, M+2 beyond the arculus ap- 

 proaches S; and in fig. 3 the basal 

 radial space is closed — that is, 3Ii+2 be- 

 yond the arculus reunites with S. In 

 figs. 1 and 3, M^ continues the direction 

 of J/i-3''; in fig. 2, JI/14-2 and ,1/j form a 

 symmetrical fork, or J/"i+2continues the 

 direction of 3A-3. 



(< The question arose whether this vein is a branch of .1 or C^. The opinion expressed above is 

 that of Professor Needham, to whom I am also indebted for other suggestions in terminologj . 



bNot labeled on fig. 1. 



cM\-3 is the upper sector of the arculus. It is the trunk from whicli arise the fir.st, second, and 

 third branches of .V, and extends fnim AR to the origin of .I/1+2. 



