22 4 c. (). WHITMAN. 



Food. — Clepsine marginata is a fish-parasite. It is commonly 

 stated in text-books that Clepsine is a sponger upon snails, 

 which may be true of some other species. They require no food 

 during the late autumn and winter months. If fed at the end 

 of March they will produce eggs without further feeding, i.e. 

 one set of eggs. When hungry they attacli themselves to some 

 object by the j)osterior sucker, and swing at full length in all 

 directions from the point of attachment awaiting the approach 

 of a fish. 



Timfi of Deposit. — Ch'psine sexoculala begins to lay eggs 

 about the first of April ; sometimes if the season be colder than 

 usual, not before the middle of this month. The period of de- 

 ])ositing is much shorter than with other species, not extending 

 much over four weeks, as Hoffmann has correctly stated. Oidy 

 one set of eggs is produced yearly. C/epshie marginafa begins 

 to produce eggs by the first of May. I have found eggs as late 

 as the middle of August. As the time required for the develop- 

 ment of the primary egg-cell into the young worm, which can 

 dispense with the protection of its parent, is in this species 

 about six weeks, it is possible that two or three sets of eggs are 

 produced annually. Tne season of egg-laying extends in C. 

 hioculala from the first of April till September. As this species 

 is often ready to lay eggs as soon as the young are ready to 

 abandon the parent, we have here the possibility of a new genera- 

 tion every month — five yearly. I have not been able to ascer- 

 tain ])recisely the period during which C. heierodita produces 

 eggs, but I think it is nearly the same as with C. manjinaia. 



Habitat. — I have obtained the greater part of my material 

 from a small brook in the vicinity of Leipsic, in places where 

 the water was about half a yard deep, and the current imper- 

 ceptible. 



I have found the eggs of C. sexoculata on stones, bricks, 

 reeds, and fallen brandies. The other species dejjosit their 

 rggs on various reeds, preferably where the bed of the brook is 

 very soft. 



Act of Lai/ing. — This process, so far as the behaviour of the 

 worm is concerned, has been correctly described by Grube ( V')j 

 lor those s])ecies which lay their eggs in sacs. Ijcuckart (,',!,".') 

 has given an excellent description of the same in the ease of 

 llirudo. Grube entertained an erroneous o])inion in regard to 

 the source of the material of which the sacs are formed. He 

 supposed that it had its origin in the ovary itself, from which it 

 was expelled just before the eggs. According to Leuckart (loc. 

 cit., p. 6S5). the sac is a product of the skni glands (Haut- 

 driisen.) The beliaviour of C. marginata during the extrusion 

 of the eggs dill'ers from that of the other species known to me, 



