CHAPTEE VI. 



Family II. MELICERTAD^E. 



Corona, not produced into setigerous lobes; buccal orifice lateral; ciliary wreath a 

 marginal continuous curve, bent on itself at the dorsal ] surface, so as to encircle the 

 corona twice, with the buccal orifice between its upper and lower curves, and having also 

 a dorsal gap between its points of flexure ; trophi malleo-ramate. 



The Melicertadce are at once distinguished from the Flosculariadm by the difference 

 of the corona, and the unsymmetrical position of the buccal orifice. In all the geneva 

 the corona bears two parallel wreaths of cilia, the upper of which frequently presents the 

 appearance of a revolving wheel. The family contains seven genera, which differ from each 

 other mainly in their coronae, tubes, and habits ; their internal structure being so much 

 alike, that it has been proposed, more than once to reduce the seven genera to two. 



There is no more interesting family. It contains animals that build their own tubes, 

 pellet by pellet ; and that themselves form these pellets, either out of external materials, 

 moulded in hollows of their own bodies, or out of their own faeces. All have social 

 instincts : some rearing their tubes, to the fourth and fifth generation, on those of their 

 ancestors, or forming dense clusters on the stems of water-plants; and others (fixed 

 fonns only in a sort of Parliamentary sense) adhering to each other by their posterior 

 extremities, and forming spherical clusters that roll unceasingly through the waters of 

 still lakes and ponds. Most of them are hardy, and luckily all are prolific ; sometimes 

 so amazingly that the water- weeds are literally covered with their tubes, and the 

 fortunate finder can thus have in the small compass of a live box scores of animals of all 

 ages, and in every stage of growth. 



Genus MELICEBTA. 



GEN. CH. Corona of four lobes ; dorsal gap wide ; dorsal antenna minute ; ventral 

 antennas obvious. 



The tube varies in all the four species, and its structure and formation will be 

 described under each. In all there is an inner gelatinous tube, 2 and in M. ringens and 

 M. conifera there is also an outer tube, consisting of pellets of extraneous matter ; 

 while in M. Janus the pellets are faecal. In M. tubicolaria the outer tube is entirely 

 absent. 



The corona seen dorsally looks somewhat like a heart's-ease, with its four petals 

 lying in a plane ; but a side view shows that the two lower lobes are bent upwards, 

 so as to form an oblique angle with the upper lobes. A groove runs round the 

 corona, on both sides, just under its edge ; and on the ventral surface it is confluent 

 with the buccal funnel. There is a gap in the groove on the dorsal surface, so that 

 it does not entirely surround the corona. The edge of the corona is fringed with large 

 cilia, and the edges of the groove and buccal funnel with much smaller ones ; and they 



1 In one instance (that of Conochilus volvox) read ventral for rlorsal. 



- This inner tube can be seen in the young animal (PI. V. lig. Id and PI. VI. fig. Iij) before the 

 outer tube lias been completed. 



