F. W. PHILLIPS — OnSERVATIONS ON EOTIFEES. 119 



size ; it is very transparent, and the whole of the muscles and in- 

 ternal arrangements can easily be seen. The stomach is hemi- 

 spherical ; it has three eyes, and is destitute of foot, intestine, and 

 anus, the excremeutitious matter being discharged through the 

 mouth. This genus was the tirst in which the male (fig. 8«.) was 

 discovered. It is hardly ^th the size of the female. Locality : 

 Hertford Heath. 



9, 10, 11. Ilydatma senfa, Triartlira hngiseta, and Rhinops 

 vitrea, all members of the large family Hydatinte. They are all 

 voracioxis feeders, devouring the Euglena and Protophytes of all 

 kinds at a fearful rate ; their habits arc extremely restless ; and if 

 you want to examine them, you must exercise considerable patience 

 or gentle persuasion in the shape of a squeeze in the live-cage ; 

 this must be done with great nicety, or a rupture of the integument 

 is the consequence. Localities : Hertford Heath and Hoddesdon. 



12, 13, 14, and 15. Members of the family Euchlanidota ; their 

 names are Eiichlanis triquetra, Motiosti/la quadridentata, Dinocharis 

 tetractis, and Stephanops lamellaris, — little creatures, with very long 

 names. In Stephanops the lorica is extended into a beautiful hood 

 or diadem, and in Dinocharis it is elegantly marked with delicate 

 granules. Monodyla, as the name implies, has but one styliform 

 tail, but it moves so constantly backwards and forwards as to 

 create an optical illusion, and appear double. All these species I 

 have found in the ponds in Hertford Heath. 



16 and 17. A species of Philodina I found in great abundance in 

 one of my aquaria in 1878. I am unable to name it. 



18. Rotifer vulgaris. This species, which is of common oc- 

 currence, 1 have already described as a typical representative of 

 its class. 



Perhaps a few words on the collection and maintenance of the 

 Rotifera may be of interest to our members. 



The apparatus that is required for their collection is very simple, 

 consisting only of a walking-stick, a few wide-mouthed bottles, 

 and a piece of fine muslin. Choose a bright sunshiny day, and on 

 arriving at a pond walk to the windward side and take dippings 

 from the surface, the middle, and the bottom of the water, and 

 strain these dippings through the muslin, which will retain all but 

 very minute animalcules. After this has been done several times, 

 the strainer should be well rinsed in one of the bottles, and a little 

 piece of weed out of the pond should be placed in the bottle. It is 

 a good plan to take a handful of weed and squeeze the water from 

 it into the bottle, a greater variety being obtained by this means. 

 Ifever mix the water from one pond with that from another, as a 

 desperate fight might result. 



I would most strongly recommend those who wish to make a 

 study of the Rotifera to keep by them two or three aquaria. The 

 square cases are the best, but an inverted bell-glass will make a 

 very good substitute. It is advisable to keep one in a dark corner 

 of a room, another in a stronger light, and another out of doors. 

 All should have a plate of glass laid over the top to exclude the 



