12 Mr. F. E. Beddavd on the 



EXPLANATION OF PLATES I. & 11. 



[All the figures refer to Mumm neozdanica.'] 



Fig. \. Dorsal view (taken from a rather small female), showing some of 



the appendatres only. X 19. 

 Fig. 2. Antennule, X 52. 

 Fig. 3. Lateral portion of the head, showing the eyes and the insertion of 



the antennules and antennie (from a smaller specimen), X o2. 

 Fig. 4. Upper lip, with front part of the head, a, from above, X 22 : h, 



from below, X 52. 

 Fig. 5. Mandibles : a, extremity of right mandible, X 125 ; h, palp of 



mandible, X 00. 

 Fig. 0. Lower lip, X 52. 

 Fig. 7. Maxillipc'de, X 52. 

 Fig. 8. First pair of legs : a, of female, X .52 ; 6, of a young immature 



male, X 52; c, of a young male, more developed, X 52; d, of 



fully developed male,"x 2;i. 

 Fig. 9. Second pair of legs (of male), X 2.3. 

 Fig. 10. Fifth pair of legs (of male), X 23. 

 Fig. 11. First pleopoda : a, of female, forming an operculum. X 20 ; b, 



of male, forming male organ, from below, X 52 ; c, extremity of 



the same, from above, showing ducts &c., X 52. 

 Fig. 12. Second pleopoda of male, X 52. 

 Fig. 13. Third pleopoda, X 52. 

 Fig. 14. Exopodite of fourth pleopoda (?), x 52. 

 Fig. 15. Uropoda, X PO. 



II. — Xote upon the Encyslmfnt o/'^olo.soma. 

 By Frank E. Beddard, M.A., F.R.S.E. 



The observations to be recorded in llic present note were 

 made upon material kindly supplied to me by Mr. O. H. 

 Latter, Science Master at Charterhouse. Knowing my 

 interest in this group of Worms, Mr. Latter was so good as 

 to forward me three tubes containing decaying plants from an 

 aquarium, among which were a large number of specimens 

 of one of the species of uS^olosoma with red oil-globules in the 

 integument. Two or three individuals were found in every 

 sample of the water from these tubes examined with the 

 microscope ; they were of varying sizes, some being twice or 

 even thrice the bulk of others : reproduction by gemmation 

 was not going on with any vigour — a fact possibly due to the 

 commencement of the cold weather ; nor, on the other hand, 

 were there any indications whatever of sexual maturity. 

 "With the cessation of the asexual method of reproduction one 

 would perhaps expect to meet with some indication of the 

 acquirement of .sexual organs ; but no such indication was 

 observable in any of the individuals which I submitted to 

 examination. The sexual oigans of ^l^olosoina Ehrcnbcrjii 



