Mr. H. J. Carter on a Lacustrine Bryozoon allied to Flustra. 1 69 



of fibres ; each fasciculus is twisted together near its centre; these, 

 some of them being larger than others, star the structure thickly, 

 and still more plentifully where the white excrescences appear. 



I am not prepared to state that this case was built by the 

 animal, and some have suggested that it may be one of the 

 Medusce ; but the microscopic structure appears to negative this 

 latter idea. 



That it is the nest in which the animal dwelt appears certain, 

 but how it was constructed we have no information to guide us ; 

 still it is not at all improbable that there are many processes in 

 the lower forms of life that have not yet been made known, 

 some of which may be even more astonishing than the supposed 

 fact, that an animal whose constant habit is to dwell within the 

 protecting walls of another, can, upon being expelled by accident 

 from its usual abode, secrete a substance that will protect it 

 from external injury, and, as far as may be, fulfil the conditions 

 of its normal position. 



EXPLANATION OF PLATE VIIL 



Fig. 1. Case of Siphonocetus typicus, enlarged (after Kroyer). 

 Fig. 2. Tubes of Siphonocetus crassicornis on Antennularia, enlarged. 

 Fig. 3. Nests of Podocerus pulchellus on Laomedea, enlarged. 

 Fig. 4. Nests oi Podocerus fucicola"? on Ulva and Tubularia. 

 Fig. 5. Nests of Amphitoe rubricata at the root of Laminaria. 

 Fig. 5 a. Microscopic structure of the same. 

 Fig. 6. Supposed nest of Phronima. 

 *Fig. 6 a. Microscopic structure of the same. 



XVII. — Description of a Lacustrine Bryozoon allied to Flustra. 

 By H. J. Carter, Esq., H.C.S. Bombay. 



[With a Plate.] 



The following is a description of a polypidom which was sent 

 to me by the Rev. S. Hislop, who found it for the first time in 

 April last, growing plentifully on Paludina Bengalensis and the 

 stems of aquatic plants, in a freshwater tank and adjoining well 

 at Nagpoor, in Central India. So far as I am aware, it will 

 form the first on record of a freshwater species of this kind of 

 Bryozoon ; and being encrusting and without calcareous matter 

 in the skeleton, it will also afford the type of a new genus at least, 

 for which I propose the name Hislopia, in honour of the reverend 

 gentleman above mentioned, to whose acute observation and 

 intelligence we are indebted not only for its discovery, but, in 

 conjunction with his late colleague, the Rev. R. Hunter, for 



