30 



The Canadian Field-Naturalist 



[Vol. XXXIV. 



caprifoliaceae 



Linnaea borealis L. var. americana (Forbes) 

 Rehder. 



Viburnum pauciflorum Raf. 

 campanulaceae 



Campanula rotundifolia L. 

 lobeliaceae 



Lobelia spicaia Lam. var. hirtella Gray. 



COMPOSITAE 



Artemisia caudata Michx. 

 Bidens cernua L. 

 Erigeron philadelphicus L. 

 Petasites sagiitatus (Pursh) Gray. 



irigonophyllus Greene. 

 Solidago mulliradiaia Ait. 

 Taraxacum officinale Weber. 



CANADIAN SPHAERIIDAE. 



By The Hon. Mr. Justice Latchford. 



(Continued from Vol. XXXIIl, page 86) 



2. Sphaerium CRASSUM Sterki. This species 

 was described in 1901 from shells procured in North- 

 ern Michigan. In Ontario it has so far been found 

 in but one locality an artificial water-course, made 

 about twenty-five years ago to intersect the flow of 

 Cave creek across Holland Avenue, and divert it 

 directly northward to a new outlet above the Little 

 Chaudiere rapids. The members of the Club are 

 now regrettably few who can recall the time when 

 this stream disappeared into a rocky cave or fissure 

 in Hintonburg, south of the Richmond road, and saw 

 light again only when nea'r the foot of Lazy Snye 

 le Chenal Paresseux of the rivermen a locality pro- 

 lific in molluscs in those remote days, though now 

 foul and virtually barren. 



A few immature shells, collected long ago in Cave 

 creek, on the Stewart and Hinton farms, when it 

 contamed a large volume of water, which were 

 thought to be 5. sulcatum, were probably S. crassum. 

 But the very metropolis of the species was not dis- 

 covered until many years later. It was not is, I 

 regret to say in the deepest part of the cutting 

 through the Black river limestone, north of the 

 Canadian Pacific Railway, in the line of Holland 

 Avenue produced. There was at the time about 

 a foot of clear water at the bottom of the trench, 

 flowing freely over a few inches of small pieces of 

 rock in many cases fragments of cephalopods, 

 corals and brachipods that had flourished and per- 

 ished on the shores of a torrid sea in the inconceiv- 

 ably remote era when this limestone was in process 

 of formation. Among these relics of primaeval 

 faunas the new species was unexpectedly found 

 in great numbers and beautiful form. Dr. Walker 

 has courteously afforded me an opportunity of 

 examining specimens of the type lot from Michigan. 

 Our shells are larger and more robust, but appear 

 to be identical in many of their aspects. 



It is fortunate that an extensive series was secured 

 during the season when S. crassum was first ob- 



served, as more recent visits to the locality proved 

 absolutely fruitless. The new intercepting system of 

 drainage along Wellington Street had cut off the 

 flow of water from the south, and large blocks of 

 stone fallen from the banks had clogged the cutting 

 so that little water flowed through it. Of this rare 

 and remarkable species not even a "bone" as a 

 mere value or empty shell is called could be 

 found, though many of Lymnaea palustris (a pond 

 snail that ranges deeply over three continents) and 

 of a large form of Planorbis trivolvis were noticed. 

 However, on passing cut of the cutting, and reach- 

 ing a muddy pool in the stretch extending directly 

 southward to the railway, a few good specimens of 

 5. crassum were procured. This locality was still 

 producing sparingly in August, 1919. For a few 

 more years it will doubtless afford opportunities for 

 collecting this fine shell, and then, like the ponds 

 which once existed near Gladstone Avenue and St. 

 Louis' Dam, be swallowed by the insatiable city. 



5. crassum, when mature, is easily distinguished 

 from S. sulcatum, especially when large number of 

 the two species are placed side by side. To state 

 the precise differences briefly and without the use 

 of many technical words is difficult. Perhaps it will 

 suffice to say that crassum as found near Ottawa, is 

 less elongated than sulcatum, more inflated and 

 heavier; the umbones are larger and rounder, and 

 the beaks more closely approximate. The striae 

 are deeper, and the rest bands are less distinct ; the 

 general colour, a deep ashy grey, is much more 

 uniform. 



This fine Sphaerium probably occurs in other 

 places in Ontario. I have a few shells in poor condi- 

 tion from Masham which may be crassum. It is 

 said by Dr. Sterki to have been found in Quebec, 

 and New York, but the localities are not given.'' 



3. Sphaerium AUREUM Prime was described in 

 1851 from speciments probably found by Prof. 



oAnn. Carng. Mus. Vol. X (liilG) p. 432. 



