ACERATOPHALLUS.—-PAMMICROPHALLUS. 185 
Head smooth above. Antenne moderately long, fifth and sixth segments noticeably longer than the second, 
third, or fourth. Boy flat, parallel-sided, rapidly attenuated from the 17th segment backwards. 
Keels large, broad and long, overlapping or almost overlapping each other, the anterior border produced 
forwards and convex, the posterior border straight or lightly concave, a little produced and with a slight 
basal shoulder; the lateral margins feebly and evenly thickened, those of the pore-bearing segments 
a little more so than the others ; lateral border straight, with an anterior tooth; anterior angle rounded ; 
posterior angle sharp, rectangular on the 4th to the 7th segments and becoming gradually more and 
more produced ; that of the 17th and 18th very acute, subspiniform. The first tergal plate as wide as the 
second, with evenly convex anterior lateral border, with strongly sinuous posterior border and acute angle ; 
anterior border of second and third convex; posterior bordor lightly concave; posterior angle a little 
acute on the second, less so on the third. Dorsal surface smooth in the middle, granular on the keels ; 
no tubercles and no transverse suleus. Caudal process of anal segment narrowed, with truncate apex; 
anal sternal plate with a median pointed process between the two setiferous tubercles. Sterna wider than 
long ; posterior moieties of the last coxiform. Legs with third segment longer than the sixth, which 
is much longer than the fifth ; the latter a little longer than the fourth. 
Phallopods (according to Carl and Brolemann) comparatively long and strong, ending in two branches, the 
principal branch or seminal stile geniculate and terminating in a spoon-shaped or button-shaped dila- 
tation ; the other branch wide at the base and narrowed to a point apically. The main part of this 
distal segment excavated on the inner side, the excavation hairy; some long hairs also extend along 
the convex side of the segment up to the subsidiary branch and some tooth-like tubercles are visible 
near the base of the latter. 
Length, ¢, 30-33 millim., width 5-5 (according to Carl). 
» » ol “5 » + ¢ ” Broélemann). 
7 2, 37-89 _,, » oO ( ” am ). 
0 yy OO "9 » 6 (specimen above described). 
Hab. Costa Rica, San José! 2, La Uruca (Biolley). 
The female above described came from La Uruca and belongs to Mr. Godman’s 
collection. I am unable to separate it from the examples recorded by Carl and 
Brélemann from San José; but, considering the difference of the locality, the determi- 
nation must be regarded as doubtful. 
2. Aceratophallus lamellifer. 
Aceratophallus unicolor lamellifer, Brdlemann, Ann. Soc. Ent. France, Ixxiv. p. 346, t. 8. figg. 1-5 
(1905) *. 
Although described as a variety of A. unicolor, this form appears to me to be worthy of specific distinction, on 
account of the marked differences, mentioned above in the analytical key, presented by the phallopods. 
Brélemann was unable to detect any certain differences between the females. 
Length, 2, 31-34 millim., width 4°7-4°9. 
29 3 ’ 33-35 ” ” 4-8-5. 
Hab. Costa Rica, San José (Biolley +). 
PAMMICROPHALLUS, gen. nov. 
Allied to Aceratophallus, but with the keels not longer than the metazonites, neither their anterior nor 
their posterior borders produced; hence the keels do not overlap each other in front and behind. 
Anal sternal plate semioval, with the setiferous tubercles widely separated and the border between them 
convex. Phallopods with coxal segment small, the tracheal rod very long and slender ; joint between 
the coxa and the distal segment suture-like and apparently inflexible; the distal segment at most with 
