Vlll UEOCOPTID^:. 



Strebel has justly remarked upon the difficulty of defining 

 the Cylindrella family, its component genera being brought 

 together not on account of a number of important characters 

 common to them all, but because of the interrelations of the 

 individual genera, forming links of affinity from one group 

 of the family to another ; so that while few if any characters 

 special to the group run through all the genera, yet so inter- 

 laced are the varying combinations of structural peculiar- 

 ities, that the whole is bound into one group of forms, un- 

 doubtedly of common ancestry, and more nearly related 

 among themselves than any component of the group is to 

 genera of other families. 



GENERAL MORPHOLOGY OF UROCOPTID^E. 



The general structure of the PALLIAL ORGANS is rather that 

 of the Bulimulidce than of the Clausiliidce. The kidney is 

 about as long as the pericardium, as in the former family, 

 while in Clausiliidce it is about twice that length. As in 

 other land snails, the size of the kidney bears no constant 

 proportion to the degree of elongation of the visceral sac 

 and lung. 



The REPRODUCTIVE ORGANS have been examined in a few 

 species of Eucalodium (vol. xv, p. 1), Ccelocentrum (xv, p. 

 31), Berendtia (xv, p. 57), Anisospira (xv, p. 298), Epirobia, 

 (xv, p. 59), Holospira (xv, p. 70), Urocoptis (xv, p. 107), 

 and Brachypodella (xvi, p. 41). In the first six genera 

 (Eucalodiince) the penis is usually very short, generally thick, 

 with apical retractor, inserted on the diaphragm, and there 

 is a long epiphallus. The spermatheca is borne on a duct 

 about as long as the entire oviduct, and inserted on the 

 atrium, or at least not very high on the vagina. In the 

 Urocoptince (Urocoptis and Brachypodella), the penis is 

 longer, and the spermatheca is inserted higher; the epiphal- 

 lus is apparently obsolete. The penis may have a normal 

 retractor as in Brackypodella chemnitziana, or it may be 

 replaced by a secondary retractor connected with the ocular 

 retractor, as in Urocoptis brevis. This metamorphosis came 

 about in this way: The ocular retractor in many cases gives 



