On July 12 and 13, 1953, the writer collected three females of Typopeltis stim-psonii together with their egg-sacs at Ushibuka in Amakusa, Kyushu. The embry-onic development of this species was very similar to that of Thelyphonus caudatus. When the eggs were collected (presumedly about two weeks after oviposition) the germ disk formation was already advanced. Two days after the germ disk for. mation the abdominal process, which was identified by SCHIMKEWITSCH (1906) as primitive cumulus, appeared near the margin of the germ disk (Figs. 1, 2). Then the germ disk was transformed into a germ band, which was segmented by cros-sing of transverse grooves and the cephalic lobe, cheliceral segment, palpal segment, and four leg segments were formed (Fig. 3). The abdominal process cut out successively the abdominal segments forward and by this teloblastic growth the abdominal portion grew in length (Figs. 4-7). No abdominal appendages appeared at any stage. The lateral organs appeared within eight days after the germ disk formation (Fig. 5). Near the hatching the egg membranes were perfora. ted by the egg-teeth which developed at the base of the palps and of the legs (Fig. 8). By moving of the embryo air was drawn through the incisions made by the egg-teeth into the space between the embryo and the egg membrane. Hatching and the first ecdysis occurred simultaneously by the 18th day after the formation of the germ disk.
Myrmarachne innermichelis BÖS. et STR., Micaria claripes DÖNITZ et STR., Phrurolithus komurai YAGINUMA (=Ferreria cibunea KISHIDA) have ant-like appearances. But Myrmarachne innermichelis does not attack the ant. Micaria claripes; this spider probably feeds on ants. I have made an experiment on this species in various methods, and found this spider attacks the ant (Lasius niger LINNAEUS) at night. The cocoon of this spider is attached to the underlying surface of a stone. Phrurolithus komurai is always found beneath the stone which lies on the nest of some red ant.
This paper deals with the pattern of distribution of Atypus karschi DOENITz along the base of the dedicatory stone lantern-Ishidoro in Japanese-by the field observation. The pattern of distribution of Atypus along the base of the dedicatory stone lantern is a Poisson pattern. The divergence coefficient in a common year is about 0.6 on the average. In winter it is up to 1 and glides down to near 0.3 from Spring to Autumn, but it rises up above at just before 0.3, and it never shows under 0.3. It is found that the increasing density is apt to make the random distribution draw near the uniform distribution. In May when they begin to leave the nest, they show almost like the uniform distribution and this continues till the end of September, but grown-up individual bodies show the random distribution. The changing curve of divergence coefficient is waving curve which is compo-sed by small variance and great variance. Small variance is decided by the season, and great variance by the life history and the leaving the nest and the pattern of the larva's distribution.