250 Miscellaneous. 



On the Organization of Batrachobdella (B. Latasti, C. Vig.). 

 By M. C. Viguiek. 



This little Hirudinean lived parasitically upon an Algerian Ba- 

 trachian, DipJoglossus pictus, which, combined with a certain ex- 

 ternal resemblance, led to its being taken for Glossvphonia algira. 

 Like the latter animal, it presents only two eyes, but is in other 

 respects distinguished therefrom, even externally, by its smaller 

 size, its more regular form, not attenuated in front, its greener 

 colour, and its proportionally larger posterior sucking-disk. The 

 following are the results of its anatomical examination. 



Generative organs. — The genital orifices are situated, the male on 

 the twenty-first ring, and the female between the twenty-third and 

 twenty-fourth. There is no regular penis, but a mere button, as in 

 the Glossiphonice ; this button is generally placed a little to the 

 right of the median line, when the animal is looked at from the 

 lower surface. The epididymi are very large ; and, after a certain 

 number of folds, each of them gradually narrows into a very deli- 

 cate deferent canal. Twelve testes of comparatively large size are 

 arranged in two regular and parallel scries. The female apparatus 

 consists of two very small pyriform ovaries, from which start deli- 

 cate oviducts, opening into a very small matrix situated immediately 

 above the vulva. The latter is transverse and always exactly 

 median. 



Digestive apparatus. — There is, as in the Glossip>honia>, an exser- 

 tile trunk, behind which the oesophagus has the aspect of a muscular 

 tube with longitudinal and annular fibres. Above the genital 

 apertures there is a large pyriform brownish inflation, visible by 

 transparence in the living animal, and which is constituted, from 

 without inwards, by rather voluminous brownish cells, and by 

 larger clear cells with a brilliant nucleus, arranged all round the 

 lumen of the digestive tube. Immediately behind this inflation, 

 which, no doubt, performs the function of the liver, are the first 

 lateral caeca, which pass in front of the first testes ; five other coeca 

 on each side pass between the testes of each row. Lastly, a seventh 

 pair of narrow caeca comes behind the last pair of testes. The axial 

 portion of the digestive tube between the caeca presents small tur- 

 bid cells, which also perhaps have the function of hepatic cells. 

 Behind the seven pairs of narrow coeca, and where the cavity of the 

 body is no longer occupied by tho testes, come four pairs of large 

 caeca — the first two pairs directed slightly forward, the third nearly 

 transverse, the fourth directed backward. The terminal portion of 

 the digestive tube makes a small loop to the left, and is then directed 

 in a straight line to the anus. 



Circulatory apparatus. — The circulatory apparatus much resem- 

 bles that described by Budge in Clepsine ; one may even say that 

 it is nearly identical, at least so far as I have been able to discover. 

 The vascular loops of the head, however, advance in front of the 

 eyes further than is figured by that author. Tho cardiac vessel is 

 exactly similar. 



