608 SUMMARY OF CURRENT RESEARCHES RELATING TO 



but that it represents a very characteristic sub-order "Dermodermaptera" 

 Verhoeff. 



Compound Eyes of Machilis.* — Frances Seaton has investigated 

 the compound eyes of Machilis variabilis, which is found in great 

 numbers on the under surface of stones which lie near the water's edge 

 at the bottom of Fall Creek gorge, Ithaca, N.Y. A description is given 

 of the corneal cuticle, the corneal hypodermis (two to each ommatidium),. 

 the four long cone-cells of each ommatidium, the distal pigment, the 

 rhabdoms, which are quite distinct and separate from the cones, the 

 retinulae, and the nerves. Since there is in Machilis no shifting of the 

 iris pigment and since the rhabdoms are of uniform width, the insect 

 has, according to Exner, day eyes with apposed images. 



p. Myriopoda. 



Variation in Lithobius forficatus.f — S. E. Williams has studied at 

 Cold Spring Harbor, Long Island, the variations of this cosmopolitan 

 centipede. He took account of the number of prosternal teeth, the 

 number of joints in the antennas, the number of coxal glands, pits or 

 pores which are found on the coxae of the last four pairs of legs- 

 (twelfth to fifteenth). He found that length of body has essentially 

 nothing to do with the number of antennal joints in specimens 15 mm. 

 long or more ; that length has very little to do with the number of 

 prosternal teeth ; that length has some bearing on the number of coxal 

 pores in the adult ; the correlation being closer on the thirteenth and 

 fourteenth legs than on the twelfth or fifteenth legs ; that the coxal 

 pores show a greater segmental or serial correlation in the case of the 

 thirteenth and fourteenth legs than bilateral symmetry ; and that 

 variations in this species point toward the normal condition in other 

 species. 



7- Prototracheata. 



New Species of Peripatus.* — Eichard Evans describes Peripatusr 

 guianensis sp. n. Out of nine specimens eight were females ; six of 

 these were larger than the male. The male had twenty-four pairs of 

 appendages, one female twenty-seven, the others twenty-eight. The 

 renal apertures of the fourth and fifth pair of legs are placed on top of 

 a papilla situated between the third and fourth spinous pads. The 

 papillae situated near the mid -dorsal line are large, and stand on a base 

 line which is almost rectangular. Principal papilla? alternate almost 

 regularly with accessory papillae. On the flanks the latter become 

 broken up into several small ones, which occupy the spaces between the 

 primary papilla?. 



The female is possessed of receptacula seminis and ovorum. The 

 ova are small, devoid of yolk, and endogenous. The embryos in the 

 uteri are in successive stages of development. The male has an elongated 

 common duct and on the twenty-second pair of legs has two pairs of 

 sexual papilla?. 



* Amer. Nat, xxxvii. (1903) pp. 319-29 (9 figs.). 



t Tom. cit., pp. 299-312 (10 figs, and 9 tables). 



% Quart Journ. Micr. Sci., xlvii. (1903) pp. 145-GO (2 pis.). 



