ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 57 



Epidermis of Tubifex.* — Mr. Lewis Atheston Las investigated this 

 subject, with special rt-ference to the nervous structures connected with 

 the epidermis. He finds that, except at the caudal end, the epidermis 

 consists of a single layer of cells. The caudal end is the region where 

 the epidermic cells originate, and in it there is an incomplete layer of 

 basal cells beneath the other cells. From these basal cells gland-cells 

 originate. In addition to basal cells and gland-cells, the epidermis 

 contains supporting cells and sensory cells. The latter may occur 

 (1) singly, (2) in indefinite groups, or (3) aggregated into distinct 

 sense-organs ; all are connected with the central nervous system by 

 nerve-fibres, and externally bear sensory hairs. Of the three types of 

 sensory structures, the first (the isolated cells) occur over the whole 

 body, the second (the groups) are present everywhere except at the 

 extreme anterior end of the body, while the definite sense-organs are 

 confined to this extreme anterior region, being especially abundant on 

 the prostomium. 



New Leechea. - ]" — Mr. J. Percy Moore has descriptive notes on the 

 collection of leeches in the U.S. National Museum — a small collection 

 of 29 species, of which 6 are new. The most interesting is Prutoclepsine 

 sexoculata g. et sp. n., which exhibits primitive external characters in 

 the retention of the full number (3) of annuli in all of the anterior 

 somites, and in the elevation of the eyes upon papillae which stand in 

 serial relation to the dorsal median segmental papillae of the succeeding 

 somites. 



Agreeing with Whitman, but not with Apathy, Moore regards the 

 primitive typical leech somite as consisting of three annuli. When the 

 primitive tri-annulate character of the somite is lost, this may take 

 place : — (a) by reduction, which has occurred as a result of the coales- 

 cence of the primary rings at the anterior and posterior ends of nearly 

 all leeches and in the genital regions of some ; or (b) by elaboration, which 

 has taken place in the somites of the middle body region, especially of 

 the Gnathobdellidae, Herpobdellidae, and Ichthyobdellidae. The increase 

 in the number of annuli by which this elaboration is expressed seldom 

 or never occurs by the actual intercalation of new rings, but only by the 

 growth and lesser or greater subdivision of the three primary rings. 



Australian Land Leeches.^ — Miss Ada Lambert describes two new 

 leeches, one of which is apparently identical with a form sent by Prof. 

 Haswell to Prof. Whitman, and referred by him to a new genus Geo- 

 bdella. This species is now described by Miss Lambert as G. whitmani, 

 while the other species is referred to the same genus as G. australiensis. 

 Both agree with Philaemon pungens previously § described by Miss 

 Lambert, and differ from all other known land leeches in possessing 

 two jaws only, the median dorsal jaw being absent. The anatomy of 

 the new forms is briefly described. 



Abnormality in a Leech. || — Emile Andre describes a variation in 

 the male reproductive apparatus of Hirudo. The two sides were separate 



* Anat. Anzeig., xvi. (1899) pp. 497-509 (5 figs.). 



t Proc. U.S. Nat. Mus., xxi. (1899) pp. 543-63 (1 pi.). 



t Proc. Roy. Soc. Victoria, xi (1899) pp. 156-63 (2 pis.). 



§ Cf. this Journal, 1898, p. 629. 



|j Eev. Suisse Zool., vi. (1899) pp. 427-8 (1 fig.). 



