of Limulus than to that of Thelyphonus, we must not forget that Holm has found important corroborative evidence for his sex determination of the male in the clasping organs of the second endognathites.
Accepting the determinations of Woodward, Schmidt and Holm, the female appendage consists of two single lobes and two paired terminal
 Figure 18 Diagram to indicate the probable nature of the mesosomatic segments of Eurypterus. Ut. masc., Uterus masculinus; gen duct, genital ducts. (From Gaskell) |
 Figure 19 Eurypterus fischeri Eichwald. Female genital appendage of operculum. At the right the tubular appendage. (From Holm) | |
 Figure 20 Eurypterus lacustris Harlan. Specimen showing the paired genital appendages turned to one side. Natural size |
pieces.[1] The first of the single lobes is the largest; it is pointed in front, where it extends between the pentagonal basal pieces, with which it is connected by sutures. The middle portion is found occupying the space between the lateral opercular plates which here do not meet in the median
- ↑ Holm also counts the two pentagonal anterior areas [see above] as belonging to the genital appendage.
