306 W. B. BENHAM. 



Fig. 25. — Microchaeta. a, h. Genital and alimentary 

 systems and nephridia. Copied from my own figures of 

 Microchseta rappi, 'Quart. Journ, Micr. Sci./ xxvi^ 

 pi. XV. The caecum of the nephridium is less marked in the 

 anterior nephridia (n.). In the posterior nephridia (n.^), in 

 Somite Xj et seq., the caecum (c(e.) is very large. In a, o. is 

 ovary ; od. oviduct ; os. ovisac ; sp. the numerous small sper- 

 mathecae. As mentioned in the body of this paper, the 

 peristomium in M. beddardi is provided with setae, so that 

 the ovaries and testes are morphologically in their normal 

 position. In M. rappi, however, there is no trace of setae in 

 the peristomium, so that the gonads appear in one somite in 

 advance of the normal position. In 6, g. is the gizzard ; ca. 

 the calciferous diverticulum ; s. the commencement of the 

 sacculated intestine. In c, three normal somites are shown. 



Distribution : Cape of Good Hope and Natal. 



Fig. 26. — Urobenus. «, h. Genital and alimentary systems 

 and nephridia. Copied from my own figures in ' Quart. Journ. 

 Micr. Sci.,' xxvii, pi. viii. The anterior nephridia (n.n.) are 

 larger than the following ones (n.^), and the caecal portion 

 (c^.) of the duct is less developed. In a, sp. marks the first 

 spermatheca. In h, g. is the gizzard ; ca. the first calciferous 

 diverticulum ; p. the first of the series of pouches of the intes- 

 tines ; p.^ the last of the series, — the intermediate eight somites 

 are removed ; c. the peculiar caecum in Somite xxvi, and s. 

 the commencement of the sacculated intestine, c represents 

 Somites xix, xx, and xxi, to show the setae, nephridiopores, 

 and spermiducal pores. 



Distribution : Brazil. 



Fig. 27. — Hormogaster. a, b. Genital and alimentary 

 systems and nephridia. Modified from Rosa's figures of H. 

 redii in ' Sulla Struttura dello H. redii/ Torino, 1888. We 

 have no information as to any variation of nephridia. sp. 

 Spermatheca. os. Ovisac, g.^, g.^, g.^ The three gizzards, c. 

 Globose caecum in Somite xxi. Six somites are removed, c 

 represents three ordinary somites. 



Distribution : Italy. 



