in development in the two sexes, differences of this nature occur. In the present genus, the male has an almost flat caput, while the female has a strongly elevated one; and with respect to the variation in the tarsal claws, no special weight can be attached to it in the present instance, since these claws are not uniformly denticulated in the different feet of the same individual. Another difference is the absence in the male of sundry small but distinct tooth-like spines at the apex of the labium and the inner corner of the base of the maxillæ; the female is also wanting in regard to the very characteristic transverse indentation which divides the caput of the male into two parts. I can, however, trace in the female the slightest possible corresponding depression, scarcely amounting to an indentation, and placed rather nearer to the junctional thoracic pit.
With regard to the differences between this species and Ct. Sauvagii, Latr. (Ct. fodiens, Walck.), size alone would suffice to distinguish them; two females of the latter now before me measuring 13 lines in length; while the male (Aran. nouv. ou peu connus du Midi de l'Europe, par Eugène Simon, Mém., Liège, 1873) measures 8 lines (17 mm.) and the female rather over 14 lines (30 mm.), the fore-central eyes in the female of Ct. Sauvagii appeared to be smaller than those in Ct. Moggridgii and placed rather farther forwards, but the eyes in both are otherwise remarkably similar both in size and position. The males, however, cannot be confounded inasmuch as, according to M. Simon, no trace of any transverse indentation on the caput exists in Ct. Sauvagii.
The denticulation of the tarsal claws in the females
