312 W. B. BENHAM 



[The following figures are placed out of their proper place, as they have 

 been constructed during the passage of the text through the press.] 



Fig. 33. — Pygmoeodrilus. a. Genital organs, partly from 

 Michaelsen's figure of P. quiliraanensis ['Jahrb. d. ham- 

 burgh wiss. Anstalten/ vii, 1890]. sp. Spermatheca, with its 

 numerous diverticula, s. Sperm-sac. m. Muscular thickening 

 of the sperm-duct. bc. Bursa copulatrix, which contains a penis. 

 PRO. The lay prostate ; the narrow portion is muscular, the distal 

 region is glandular, h. Alimentary canal, from IMichaelsen's 

 description, ca. Calciferous diverticulum. There is some doubt 

 experienced as to the existence of a gizzard. The nephridia are 

 not described beyond the statement that there is a pair in each 

 somite, c. Exterior of three somites, showing setae in couples ; 

 the nephridiopores ; and male pores in xviith Somite. 



Distribution : Quilimane, near Zanzibar. 



Fig. 34. — Nemertodrilus. a. Genital system, from 

 ]VIichaelsen's description of N. griseus in ^Jahrb. d. ham- 

 burg, wiss. Anstalten,^ vii, 1890. s^ Anterior sperm-sac. 

 s". Greatly elongated posterior sperm-sac. os. Ovisac, which 

 is prolonged backwards (os^.) and is regarded by INIichaelsen as 

 '' spermatheca." pro. Prostate, h. Alimentary tract and 

 nephridia, from IMichaelsen's description, g. Gizzard, s. 

 Commencement of sacculated intestine. No details as to 

 nephridia are given, except that they are a pair to each somite, 

 and have, apparently, a dilated " duct.^^ c. Exterior of Somites 

 XVI, XVII, and xviii, to show the couple of setae, nephridio- 

 pores, and male pores. 



Distribution : Quilimane, Zanzibar. 



Fig. 35. — Callidrilus. From INIichaelsen's description of 

 C. scrobifer, in ' Jahrb. d. hamburg. wiss. Anstalten,^ vii, 

 1890. a. Genital system, s. s,"* The first and fourth sperm- 

 sacs. SP. The numerous, small spermathecse. x. is a struc- 

 ture which JVEichaelsen identifies as a prostate. He states 

 that it is small, and from the general anatomy of the worm I 

 fancy that it may be merely a thickening of the body, such as 

 is present in Brachy drilus. h. Alimentary and excretory 

 system, m. A thickening, which is, according to Michaelsen, 

 not muscular. It probably represents a gizzard, s. Com- 

 mencement of sacculated intestine. The nephridia are merely 

 said to be paired, and to be provided with a bladder, which I 

 take to mean a '^ caecal " outgrowth of the duct. c. Exterior 

 of Somites xvi, xvii, and xviii, to show couples of setae, 

 nephridiopores, and male pores, \N.B. — I believe this worm 

 belongs to my family llhinodrilidae]. 



Distribution : Quilimane, Zanzibar. 



