182 DIPLOPODA. 
species than in WV. aztecus, the width is twice given as 8 millim. ‘This figure is in all 
probability a misprint for 3, a measurement which, when compared with the length, is 
quite in accord with the statement as to the slenderness of the body. 
4, Neoleptodesmus vermiformis. 
Polydesmus (Strongylosoma) vermiformis, Sauss. Linn, Ent. xi. p. 326 (182 05 *; Mém. Soc. Phys. 
Genéve, xv. p. 298, t. 1. fig. 4 (1860) ?. 
Colour white (probably brown when alive). Body smooth, shining, cylindrical. eels sloping, situated 
about the middle of the sides or even lower, very small, linear; area round pores swollen; pores looking 
laterally and placed in the posterior part of the swollen area. first tergal plate (judging by the figure) 
considerably narrower than the 3rd. The cylindrical portion of the segments not retracted within the 
keel-bearing portion, hence the keels are widely separated from each other on each side. 
Length 40 millim., width about 7. 
Hab. Mexico, Eastern Cordillera! ?. 
The sexual characters of this species have not been examined. Its generic position, 
therefore, is unknown. It may prove to belong to Acutangulus or perhaps to 
Dirhabdophallus. 
ACERATOPHALLUS. 
Aceratophallus, Carl, Rev. Suisse Zool. x. p. 608 (1902); op. cit. xi. p. 554 (1903) ; Brélemann, 
Ann. Soc. Ent. France, Ixxiv. p. 346 (1905). 
Distinguishable from Leptodesmus by the structure of the phallopods, the basal segment (coxa) of which has 
no calcar, while the distal segment shows no trace of a division and is extended axially in the same 
straight line as the basal segment; hollowed and hairy basally on its inner surface, distally it ends in 
two branches somewhat widely separated from each other. The seminal processes of the ¢ are elongate 
and pointed. The keels overlap, are large, subaliform, longer than the area of the metazouite that bears 
them, both anterior and posterior borders being produced. The anal sternal plate is triangular, with the 
sides nearly straight, the tubercles not widely separated from each other and the margin between them 
pointed, compressed, and subcristate. ‘ The sternal areas are wider than long, as wide behind as in front, 
except on the last two leg-bearing segments, and show no signs of having the posterior border notched 
or bidentate. The sixth segment of the leg is shorter than the third, but much longer than the fifth. 
Type, A. unicolor, Carl. 
Distribution. Central America (Costa Rica). 
The two species of this genus here admitted are separable as follows :— 
a. Principal branch at apex of phaliopod (seminal stile) strongly geniculate, with 
entire button-shaped apex; secondary branch apically pointed . 
a'. Principal branch at apex of phallopod (seminal stile) evenly and lightly curved, 
with the tip deeply notched ; secondary branch blunt at apex 
unicolor. 
lumellifer. 
i. Aceratophallus unicolor. (Tab. XIV. fig. 2.) 
Aceratophallus unicolor, Carl, Rev. Suisse Zool. x. p. 609, t. 2. figg. 35, 86 (1902) '; Brélemann, 
Ann. Soc. Ent. Fr. Ixxiv. p. 345, t. 8. figg. 6, 7 (1905) *. 
2. Colour nearly uniformly testaceous (? specimens recently moulted). 
