118 CHLORITIS. 



criterion, and considerably widening the limits of the genus. At 

 about the same time Dr. v. Mollendorff redefined Chloritis, and con- 

 cluded that the sculpture of " impressed points placed in quite 

 regular quincunx," and the presence of a " keel or angle round the 

 umbilicus" were diagnostic generic characters. In this connection it 

 should be noticed that the hairs or hair-points are totally lack- 

 ing upon the outer whorls of many undoubted Chloritis, and that 

 the umbilical angle completely fails in C. circumdata, maforemi*, per- 

 cu#m, etc. It therefore appears that the most we can say of the 

 sculpture is: apical whorls and nxtta/ly the whole shell sculptured 

 with hair-points arranged in quincunx. It is probable that when 

 hairs or hair-points are present on the last whorl, they are always 

 disposed in regular oblique sweeps or quincunx, but this cannot be 

 said to be demonstrated. Some species show a granulation between 

 the hair points. The European Oligocene and Miocene species 

 which have been referred to Chloritis such as H. lepidotricha A. 

 Br., have no relationship to the Oriental Chloritis ; the H. lepido- 

 tricha is a Campylcea. In this connection it must be emphatically 

 stated that while the character of surface-sculpture discussed above 

 distinguishes Chloritis from other groups inhabiting the same quar- 

 ter of the globe, it is not in itself a feature of much importance, 

 nor in itself diagnostic of this genus alone. In Europe the hairy 

 forms of the Campylcea planospira group (as well as some other 

 Campylseas, such as setosa Ziegl.) show absolutely the same surface 

 sculpture, from the apex out. On the other hand, the Australian 

 group Hadra is extremely close to Chloritis in anatomy, but lacks 

 the quincuncial sculpture. We may, therefore, regard the quin- 

 cuncially arranged hairs as a secondary character, which has arisen 

 independently in several widely different groups of Helices. The 

 function of the hairs is evidently to gather dirt, thus disguising the 

 snail from its bird enemies. 



Chloritis has the essential internal organization of Camcena, Cam- 

 cenella, etc. It differs from these groups and from Oblxi, mainly in 

 the non-differentiation of the embryonal whorls, and the smaller 

 size of the shell at the time its independent life begins. The spe- 

 cies referred by Semper to Chloritis belong to an entirely different 

 group. His anatomical characterization of the genus therefore 

 falls. 



Chloritis may be divided into several sectional groups Chloritis, 

 Sulcobasis, Austrochloritis, Trichochloritis probably natural, but 



