156 The Ottawa Naturalist. 



Conchology. A large land shell, new to the Ottawa 

 list, was found at Casselman on May 23rd. It is Helix paliiata. 

 Three specimens were found, one west of the South Nation 

 river, and two on the east side, below the falls, in the woods 

 where the beautiful Phlox divaricata was then in full bloom. 

 H. pallia/a is about three quarters of an inch in diameter, and 

 differs from H. denti/era, which it most resembles in general appearance, 

 in having the upper lip prolonged inward at two points into what are 

 commonly called "teeth ". A similar process is formed upon the body 

 whorl These projections permit the soft tissues of the builder to pass, 

 but oppose a pearly barrier to beetles and other enemies who would 

 intrude upon the dweller within. The three teeth on the shell of H. 

 paliiata and other American land shells have been considered a 

 peculiarity sufficiently distinctive to warrant the grouping of such 

 species in a subgenus, under the name Triodopsis. The study of the 

 inhabitants of the shells grouped under this term has shown that many 

 are less closely allied to other triodopses than they are to the mesodons, 

 or shells of which H albolabris and H. thyroides, also found at Cassel- 

 man, may be regarded as the types. The shell alone can, in fact, be 

 seldom relied on in arranging a natural classification of molluscs. 



Casselman Shells A mere list of names is dry reading 

 at best, and is of little interest to the general reader. In years 

 to come, however, The Naturalist will be referred to, to 

 ascertain what plants or shells at a particular time occurred in 

 certain places. Any record, therefore, is likely to be of some 

 use. At Casselman on May 23rd and 24th, a number of shells 

 were noticed. No great effort was made to collect anything but what 

 came in the way of a few members of the Club, while on a botanical 

 excursion. This may account for the absence from the following list of 

 such shells as H. dentifera and H. th\r aides, which are known to occur 

 at Casselman. The species noted were : Helix albolabris, H. sayi, 

 H. paliiata, H. alternata, H. concava, H monodon, H nitida, H. 

 arborea, H. radiatula, H. fulva, H. stnatella, H. pulchella, H. binney- 

 ana, Succinea oralis, S. obliqua, Vitrina limpida, Limax campestris, Teb. 

 Carolinensis, Vertigo ovata, Per, subclitidrica, Carychiutn exiguutn, Gon. 

 livescens, Cat/ip. decisum, Limrnea palustris, L. cape rat a, Physa heteros- 

 troplia, P. billin^sii, Platiorbis trivolvis, PL bicarinatus, PI. parvus, 

 Amy lus parallel us, Unio complanatits, U. luteolus, Anodanta jiuviatilis, 

 Sphaeriiivi sulcatum, S. occidentale, Pisidium abditum. L. 



