ON THE ANGUILLULIDÆ, 93 
TABULAR LIST OF GENERA. 
I. LAND AND FRESHWATER. 
Spicules two, equal, with or without a single posterior median accessory piece. 
* Integument plain, or with longitudinal markings. Ventral excretory gland wanting. 
+ Caudal sucker small. 
1. MoxnvsTERA. Integument with lateral circular mark anteriorly. Ocellus single, often absent. Pha- 
ryngeal cavity none. (Esophagus cylindrical. Uterus unsymmetrical. 
‚ Trınopus. Pharyngeal cavity cup-shaped ; no teeth. (Esophagus having three lobes at termination. 
Males with well-developed suckers in middle line above anal cleft. 
to 
3. Mononcuvs. Pharyngeal cavity large, oval, having one upper tooth-like projection. Canal of 
esophagus indicated by three bright lines. 
++ Caudal sucker absent. 
4. Inowvs. Pharyngeal cavity small, long, and narrow. (Esophageal canal bounded by three bright 
lines. 
5. DoryLaımus. Spear exsertile, at commencement of esophagus, whose 
bright lines. Males having oblique integumental markings on posterior extremity, 
small median suckers above anal cleft. 
canal is indicated by three 
with or without 
Œsophagus having oval swelling at termination, con- 
6. ANGUILLULA. Pharyngeal cavity very small. 
cal. Spicules long and narrow. Acces- 
taining a simple valvular apparatus. Uterus unsymmetri 
sory piece single, distinct. 
** Integument with transverse strie. Ventral excretory gland present or absent. 
T Caudal sucker present. 
Œsophagus with constricted portion at 
. TaiPULA. Série well marked. Pharyngeal cavity none. 
gion. 
termination. "Three large pores through integument in anterior part of ventral re 
8. DiPLoGAsTER. Strie transverse and longitudinal. Pharyngeal cavity cup-shaped, with small horny 
plates at bottom. (Esophagus having large muscular swelling at middle of length. Sucker very 
minute. Accessory portion of penis well marked. 
+ 
*9. Puecrus. Pharyngeal cavity long and narrow. (Esophagus having oval swelling at termination, 
provided with a complex valvular apparatus. Ventral gland having twisted duct opening near mid- 
dle of esophagus. Uterus symmetrical. 
^10. APHELENcHUs. Spear simple, at commencement of esophagus, which terminates in a large 
rounded muscular swelling. Ventral gland-opening posterior to termination of esophagus. Uterus 
unsymmetrical. Spicules simple, without accessory piece. 
* All the animals belonging to the genera having this mark affixed to them have a modification of the ventral 
gland, and are endowed with a remarkable tenacity of life. 
