542 TRITICELLID^. 



Genus TRITICELLA, Dalyell. 



Der. Dim. of triticum, wheat ; named from its resemblance to a grain of 



wheat. 



TRITICKLLA, Dalyell (1848), Hem. An. Scot!.: G. O. Sars. 

 FARKELLA (part), Alder. 



GENERIC CHARACTER. STEM repent. ZOCECIA with a 

 membranous area on one side (the ventral) , flat or slightly 

 depressed ; more or less gibbous on the other (the dorsal*) ; 

 compressed laterally, attached by a movable joint to a rigid 

 peduncle. POLYPIDE without a gizzard. 



THIS is the only British Polyzoon in which the zooecia 

 are movable, with the exception of Mimosella, the sessile 

 cells of which sway backwards and forwards as the polypide 

 issues or retreats. In Triticella the cell is attached by an 

 elastic joint to the summit of the stalk, and is capable of 

 being moved about to a certain extent at the will of the 

 animal. According to an observation of Sir Philip 

 Egerton's, in Hippuraria it can be bent, so as to form a 

 right angle with the peduncle. 



In a species belonging to the present family (Lagenella 

 nutans) , and probably referable to Hippuraria, Joliet has 

 observed two groups of muscles, attached on the one 

 hand to the walls of the zocecium, and on the other to 



* " Instead of the regular cylindrical or ovate shape (of cell) which dis- 

 tinguishes all known Vesiculariidcg (including Cylindraciida'), wo meet here 

 universally in fully developed zooecia with a very characteristic bilateral 

 formation, so that we can distinguish, as amongst the Cheilostomata, a back 

 and front side, or, more correctly, a ventral and dorsal side, which in form 

 and structure are essentially different from one another The ven- 

 tral side is that immediately within which, when the polypide is retracted, 

 the tentacular wreath with the lophophore is placed ; the dorsal side is that 

 near which the alimentary canal with the anal opening lies, and immedi- 

 ately within which the sexual elements are developed." Q. O. SAUS. 



