220 Proceedings of the Royal Physical Society. 



in fact the mucus-pores can be seen as a close stippling, 

 as in P. macrostyla. I have never seen any sign of 

 viscosity about either P. hrevipes or P. citrina. The 

 occurrence of a single individual with a dirt-coated trunk 

 could not be considered of much importance, but in this 

 instance the animal was abundant, and every one was 

 alike " sordid," although other bdelloids in the same water 

 were clean. 



As the peculiarity was correlated with much smaller eyes 

 than in either of the species with which it could be compared, 

 the differences may be regarded as of some importance. 

 Considering that it has some points of close resemblance 

 to each of those species, and that it thus occupies the un- 

 enviable intermediate position, I do not feel justified in 

 bestowing even a varietal name upon it, till it has been more 

 fully investigated. 



Type. — Upper Elf Loch, November. 



Var. — In moss, Kirknewton, near Midcalder, 28th March 

 1905 (Evans). 



P. acuticornis, Murray (11). 



Bavelaw Moss, February; near Penicuik, March; near 

 Winchburgh, December. 



B. Eyes absent; oviparous. 



P. laticeps, Murray (12). 



A parasite on insect larvae living in streams. The examples 

 found were not on insects, but had no doubt been washed 

 off their hosts. 



Nether Habbie's Howe, March. 



P. plena (Bryce), (3). 



Nether Habbie's Howe, March ; Fullarton, November. 



P. vorax (Janson), (6), (3). 



Thornton, Fife, April 1905. This is, so far as I can 

 ascertain, the first notice of the species in Scotland. Mr 

 Bryce has before found it several times in England. 



P. brycei (Weber), (17). 



Two principal varieties are distinguished. The commoner 



