736 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxi. 



characters in common with Tycodesmus in the emargination of the 

 posterior rim of the aperture in wliich are inserted the copulatory legs 

 and in the development of distinct processes at the bases of the last 

 pair of legs of the eighth segment, but these processes are distinctly 

 flattened, not conical as in Tycodesmus; the emargination of the rim of 

 the copulatory aperture is much less than in Tycodesmus medius. With 

 the partial exceptions just noted, the secondary sexual characters are 

 those of Astrodesmus. The process of the sixth segment is even wider 

 than in the other species of Astrodesmus^ in striking contrast to the 

 very slender process in Tycodesmus. 



ASTRODESMUS TANGA, new species. 

 (Plate ].XI, fig. 5a.) 



Known only from the female; similar, but not closely related to A. stel- 

 lifer, in that the bod}^ is larger and more robust, and the segments dis- 

 tinctly more convex dorsally; the carinte of the first segment, though 

 not sharp, are distinctly more produced and pointed than in A. steUifer 

 and have the marginal callus much shorter; the calli of poriferous 

 segments are distinctly broader and shaped much as in Aulodesmus 

 mossamhicus; the carinas of posterior segments much more distinctly 

 produced caudad, the corners sharp and spiniform ; the dorsal surface 

 is rather uneven, distinctly and rather densely rugulose laterad and on 

 the carinjTp; the last segment is more robust and more broadly truncate. 

 Legs longer and more robust, and the secondary carinte distinctly more 

 prominent than in the other species of Astrodesmus. 



Color of alcoholic specimens very dark olive brown; the carinje, legs, 

 and antenniv yellowish. 



Length, about 65 mm.; width, including carinte, 13.5 mm.; without 

 carina?, 9.5 mm. ; length of antennae, 8 mm. ; of leg of tenth segment, 

 9 mm. 



Locality. — Tanga, Usambara, German East Africa, the type a female 

 specfmen collected by Eeimer, in the Berlin Museum, where there is 

 another entirely similar female from the same region. 



As the body cavity of males of Astrodesmus steUifer measures only 

 about 8 mm. it is evident that in the present species the body is heavier 

 at the expense of the carina^, as the total measurement is more nearly 

 the same. Such a difterence might be expected in females, but not to 

 so great an amount, and a female referred to steUifer differs from the 

 males to a much less extent in dorsal convexity,. so that, together with 

 the other differences enumerated, it is not impossible that the discovery 

 of males may reveal characters which will compel the removal of the 

 present species from Astrodesmus. 



