300 W. B. BENHAM. 



Fig. 19. — Plutellus. a. Genital system. The position 

 of the genital organs is very abnormal, and requires confirma- 

 tion, s. The sperm-sacs in Somite xii. sp. The first of the 

 five spermathecse. pro. Prostate. The sperm-funnels and 

 ducts are unknown, o. Ovary in Somite x; and on., the ovi- 

 duct opening externally in Somite xi. b. Alimentary system. 

 G. Gizzard, ca. Calciferous diverticula, s. Commencement of 

 sacculated intestine. The nephridia are shown alternating in 

 position, the first four pores being in line with the third seta, 

 the rest alternating with second and fourth setje. Moreover, 

 the funnels are said to be in the same somite as the coiled 

 tubule and external aperture, n.^ The first of the series of 

 nephridia which open in line with the third seta, n.^ The first 

 of the series which open in line with the fourth seta, n.^ 

 The first of the series in line with second seta. c. An external 

 view of Somite vi, to show spermathecal pore (black) in line 

 with second seta, and nephridiopore (n^) in line with third 

 seta ; of Somite xii, to show the normal arrangement in the 

 even numbered somites; and of Somite xiii, to show normal 

 arrangement of the odd numbered somites. Composed from 

 Perrier's description of P. lieteroporus in 'Arch, de Zool. 

 Exper. et Gen.,' ii, 1873, p. 331. 



Distribution : Pennsylvania. 



Family VI. — Perionycid^. 



Fig. 20. — Perionyx. a. Genital system, o. Ovary, on. 

 Oviduct. PRO. Prostate, b. Alimentary system, g. Gizzard. 

 s. Commencement of sacculated intestine. Modified from 

 Perrier's figures of P. excavatus in ' Nouv. Arch. d. Mus. 

 d'Hist. Nat.,' 1872, in accordance with Rosa's description of 

 the same species in 'Ann. Mus. Civ. d. St. Nat. di Gcnova,' 

 vi, 1888. c. External view of three somites, showing the 

 numerous setae and the paired nephridiopores. 



Distribution : India, Burmah, Philippines. 



