124 



From specimens obtained at tlie head' of the Rifta Tt.inge Rapids 

 along the Rideail River by the writer arl^d froiii those of the National 

 Museum collection kindly place I at the disposition of the v(-ritet- by Mr. 

 Whiteavei?, the following notes have been gathered : 



Specivien No. i. Collected at the rapids along the Rideau River, 

 opposite tlie Rifle Range, in Gloucester, Collector H.M A., 188G. 



This specimen agrees well with the beautiful and clear descriptidn 

 given by JDr. Davidson in his " Supplement to the British Silurian 

 Brachiopoda, 1882- 188-1, p. 217," and only slight varidtiohs such as 

 might be merely local can be observed. The dimensions of the shell 

 are as follows: Length, twelve and a-half millimetres; breadth, eleven 

 millimetres ; height, measured at about one third the distance from the 

 beak to the anterior exti-emity, two millimetres. Length of the loiigest 

 spines, seen along the anterior margin, three rriillimetres. 



Specimen No. ^2. Collected by Mr. J. W. H. Watts on his pro[)erty, 

 Cummings' Bridge P. O., Ont , near Otta\*a City, 18S3. 



This specimen exhibits the spines all afouhd the outer margin of 

 the valve from near the beak on one side round the front margin and near 

 the beak on the other side- These spines, the longest measured as yet, 

 gave three and a half millimetres, or one and a half lines in letigth. In 

 the centre of the umbonal region where the valve rises abruptly from 

 the beak hear tlie latter there is a clearly defined sinus or groove ex- 

 tending only a short distance anteriorly and dying but on the gently 

 covex or rtrche'd valve. This feature is also present in th^e next. 



Specinen No. 3. Collected by Mr. J. W, H. Watts at the same 

 locality as No. 2. 



A very typical example of the species indeed, whose length is 

 twelve and a half millimetres (6 lines) and breadth ten and a half 

 millirhetres (5 lines). 1'he height of the valve is two millimetres but 

 the spines being partially or wholly imbedded in the matrix their length 

 has nrtt been ascertained exactly. 



The three specimens abbve referred to, aJl- mentionei before, 

 agree well with Dr. Davidson's Scottish form Siphonotreta Scotica ; never- 

 theless as it may pbssibly happen that the Canadian form exhibits the 

 few points of variation constantly the varietal designation of Si- 



