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Show 1906.] ON MAMMALS FROM BECHUANALAND. 101 (VerrilJ, 7) resembles Corymorpha in its possession of root-like fixing-processes at the base. From all these genera of the Pennarida? (sensu stricto), however, Trichorhiza is separated by the characters of its hydrorhiza, and also by the possession of a sort of theca, comparable to that of a calyptoblast. The branches of the hydrorhiza may be compared with the filamentous processes of the base in Corymorpha, but there is no real affinity between the two structures. The medusoid of Trichorhiza, so far as one can judge from an immature specimen, resembles the medusoid of Pennaria tiarella, which, however, has no developed tentacles at all (Ayres, 2), while the medusoid of Trichorhiza seems to have one tentacle-bulb more developed than the other three, and in this respect approaches to the medusoids of the Corymorpha-\\k.Q forms, most of which bear one developed tentacle. On the whole, Trichorhiza is to be associated with thePennaria-like forms, though the characters of its hydrorhiza and its "theca" give it a somewhat isolated position among them. References. (1). A L L M A N , G. J.-Monog. Gymnobl. Hydroids, vol. ii. (1872). (2). A Y R E S , W . 0.-Proc. Boston Soc. Nat. Hist. vol. iv. (1852). (3). D E L A G E et HEROUARD.-Traite de Zoologie Concrete, tome ii. pt. 2 (1900). (4). F O W L E R , G. H E R B E R T . - I n 'A Treatise on Zoology' (Lankester), vol. ii. (1900). (5). M O T Z - K O S S O W S K A , S.-Archives de Zool. exper. et gen. ser. iv. tome iii. (1905) p. 39. (6). SCHNEIDER, K. C-Zool. Jahrb. x. [Syst.] (1898) p. 472. (7). YERRILL, A.-Amer. Journ. Sci. (3) xvi. (1878) p. 374. EXPLANATION OF PLATE V. Fig. 1. Trichorhiza brunnea. Hydro-id, p. 99. Fig. 2. Trichorhiza brunnea. Medusoid, p. 100. 5. A List of the Mammals obtained by Messrs. R. B. Woosnam and R. E. Dent in Bechuanaland. By H A R O L D SCHWANN, F.Z.S. [Received December 15, 1905.] (Plate VI*) This very interesting collection, made by Messrs. R. B. Woosnam and R. E. Dent in Bechuanaland, was obtained chiefly at two localities, viz. Kuruman and Molopo. The former is situated about 100 miles south-west of Vryburg on the Kuruman River, whose course flows parallel to the range of hills bearing the same # For explanation of the Plate, see p. 111. |