4190 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
the posterior margin, and the suture separating it from the abdomen 
is entire, asin multiplex and parvigenitalis, only asymmetricus having 
this suture interrupted medially, as shown in the figure of that species - 
(Carriker, 1936, pl. 28, fig. 1). The abdomen appears to be about the 
same, including the apical segment. 
The measurements, as compared with multiplex, are curiously vari- 
able. The body is shorter ; the head is shorter but wider; the prothorax 
is both shorter and narrower; the mesothorax of the same length, but 
considerably narrower; the metathorax both shorter and narrower; 
and the abdomen shorter but of the same width. 
The genital armature is, however, very different from all three of 
the known species, being asymmetrical to a most surprising degree. 
The left paramer is the shorter, is much constricted medially, then 
widens apically and ends in a truncated tip. The right paramer is of 
more or less uniform width, but much twisted, and ends in an out- 
curving, narrow tip. 
The endomeral plate is rather similar in general shape to that of 
multiplex, but less tapering apically, and terminates in a broadly 
rounded tip, with no sign of penis or tubular outlet. 
A projection of the basal plate extends backward along the left 
paramer for two-thirds of its length, ending in a point, while there 
is attached on the outside of each paramer, near the base, a curiously 
shaped, elongated flap, which folds back under the distal portion of 
the basal plate, the two flaps being joined medially. The whole gen- 
ita] apparatus, both for this species and multiplex, is among the most 
unbelievably bizarre and extraordinary that have come under my 
notice. The single female taken is very similar to that of multiplea 
and, like that species, is slightly smaller than the male in some of but 
not all its measurements. 
MEASUREMENTS OF MEGAPEOSTUS SECUNDUS 
Male Female 
Structure Tai TUT aS a 
Length Width Length Width 
BS Oyj NU na ates aL eye ek ee Pe EES DOS Mae eas NY ay 1.93 
18 Goa LANE rN et at pp Don aL IR NO 0. 49. 0.77 0. 51 0.77 
PProtWor aK ee eel pears RAN GLB ALA AVE RERUN GE 0. 227 0. 434 0. 217 0. 41 
TP OSO LTO re Re aN Aa co AN CHT Soha AE INS aN RL 0. 184 0. 69 0.16 0. 67 
Ie tathora xcs Gienwimnanor as fesse aU LIEN tenis UNE SUC 0. 195 0. 64 0. 217 0. 62 
PAD COMO T Be EL Dns UL et IN CCSD EUR 1.19 0. 80 1.15 0. 80 
USNb OYA) OY 02) S) ASU STE PUN Se eg 0. 33 0. 09 0. 227 0. 043 
PB ASU 1 BGG ua aE GSU ALT TEI LU 0. 456 OS26 pi eee ane 
RAPHE PAT AMON os SM eAwe Oe een SO Us ONG SES ee asa 0. 292 ON 083 Ane coe Re ata 
TeOf ts PAT AMMO Mw iN RON DEUS tle 2s A SOU Ve 0. 26 OF043))| Ave lio aa 
Pndomerali plate suse me oe Oa DS ae 0. 25 OL OGby | Sau Ni eU ne 
