2 Fi-oceedings of the Royal Society of Victoria. 



marine forms. The second species may l)e callecl Crypto- 

 zoon Goncretuin, from the manner in wliich the sandy 

 "nodes" have grown close together, with corresponding 

 shortening of the chitinous ir)ternodes. 



The new genus may be briefly diagnosed as follows : — 

 " Ctenostomatous Polyzoa, with tubular, chitinous zooecia 

 enveloped in common aggregations of sand. Polypides 

 provided with a muscular gizzard containing two horny 

 teeth." 



Before proceeding to describe the distinctive characters 

 of the two species I will give a general account of the 

 anatomy of the genus, so far as I have been able to work 

 it out in such an unfavourable subject for investigation. 



The chief difficulties in the way of a study of the soft 

 tissues in Cryptozoon, consist (1) in the very minute size 

 of the individual polypides ; and (2) in the difficulty 

 experienced in separating them from the mass of sand 

 grains in which thej' are enveloped, and to which the 

 zooecia firmly adhere. 



In the living animal I was able only to study the anatomy 

 of so nmcli as is protruded beyond the margin of the sandy 

 mass when the animal is in a state of expansion (Fig. 1), 

 that is to say, only the tentacles and a v^ery small portion 

 of the body, including the mouth and anus, together with 

 the soft retractile portion of the zooecium. Moreover, owing 

 to the impossibility of separating the ]iolypide in a living 

 condition from the sandy mass, I could only examine it with 

 a low power of the mici'oscope. 



Somewhat curious and more or less satisftictory results 

 were obtained b}'' teasing up with needles the masses of 

 sand containing living ])olypides on a slide in a drop of 

 sea water, then staining with carmine or magenta, and 

 replacing the sea water by glycerine. After this process, 

 there remains on the slide a quantity of more or less isolated 

 sand orrains, with here and there scattered about amonorst 

 them a polypide which has been forcibly torn from its 

 zooecium. 



The most interesting point about this method is that 

 the polypides are killed in an expanded condition, i.e., 

 with the lophophore expanded and the tentacles spread 

 out at length, and separate from one another, instead of 

 being all curved in and massed together in a compact bunch, 

 as is the case in spirit-preserved specimens. Sometimes the 

 lophophore, with the tentacles, is torn off from the remainder 



