January, 1922.] 



The Canadian Field-Naturalist 



occurrence of leeches are made. 



For this reason the opportunity was welcomed 

 of examining a small collection of leeches in the 

 Victoria Memorial Museum (Ottawa), for which 

 I am indebted to Mr. Fritz Johansen. The 

 present paper presents these determinations, 

 with transcripts from the labels (in quotation 

 marks) of all specimens, so that all of the locality 

 data may be specifically recorded. To these is 

 added a list of leeches from Canadian localities in 

 the collection of the Academy of Natural Sciences 

 of Philadelphia. These are designated A. N. S. 

 and include some of the material on which my 

 paper referred to above was based. 



The general result of this study is to establish 

 that most of the leeches found in the fresh waters 

 of the northern United States are distributed 

 through the southern provinces of Canada. It is 

 now possible to trace several species throughout 

 the entire east and west width of Canada. It still 

 remains to fix the northern limits of the range of 

 most species, for there are practically no records 

 except from the southern tier of provinces. That 

 leeches abound in the numerous lakes of central 

 and northern Canada may be expected. Several 

 collections that have come to me from Alaska 

 establish their occurrence in the far north, but 

 these are reserved for description elsewhere. No 

 species distinct from those known in the northern 

 United States exists in the collection. A new sub- 

 species is described but this has been known to me 

 from several points in the northern states for 

 about twenty years. 



The following key will serve for the identifica- 

 tion of the species listed: 



I. Mouth a small pore-like opening in the disc 

 of the anterior sucker through which the 

 muscular pharyngeal proboscis may be pro- 

 truded; no jaws. Rhynchobdellae. 

 A. Body not divided into two regions; 

 usually much depressed; eyes near median 

 line; stomach usually with well-developed 

 lateral caeca; complete somites triannulate. 

 Family Glossiphonidae. 



a. Genital orifices separated by a single 

 annulus; size small. 



b. Eyes one pair, distinct; gastric caeca 

 few and simple. 



1. A brown cuticular nuchal plate and 

 underlying gland on the dorsum of 

 somite VIII; body capable of great 

 extension; cutaneous papillae obso- 

 lete; color pale: pink, gray or brown- 

 ish. Glossiphonia siagnalis. 



2. No nuchal plate or gland in the 

 adult; body relatively broad and flat, 

 incapable of great extension; cutan- 



eous papillae few but variable in size 

 and number; color brownish, either 

 deeply pigmented in narrow longi- 

 tudinal lines or diffuse with trans- 

 verse rows of metameric white spots 

 on the middle annuli of complete 

 somites. Glossiphonia fiisca. 

 bb. Eyes three pairs, arranged in three 



groups of two in a triangular figure; 



gastric caeca six pairs, very slightly 



branched. 



3. Body broad and flat, moderately ex- 

 tensile; transparent, with little pig- 

 ment. Glossiphonia heteroclita. 



aa. Genital pores separated by two 

 annuli; size medium or, for the 

 family, large. 



c. Eyes three or four pairs, all distinct, 

 in two nearly parallel rows; size 

 medium. 



4. Eyes three pairs; body rather thick, 

 incapable of great extension or flatten- 

 ing; opaque, usually heavily pig- 

 mented with brown, a dorsal and a 

 ventral pair of narrow dark brown 

 longitudinal lines for nearly the entire 

 length, the former usually interrupted 

 by pale metameric spots; gastric caeca 

 seven pairs, little branched. Glossi- 

 phonia complanata. 



5. Eyes four pairs; body thin and soft, 

 capable of great extension; trans- 

 parent, lightly pigmented with green 

 and three series of small pale yellow 

 spots; gastric caeca nine or ten pairs, 

 moderately branched. Protoclepsis 

 occidentalis . 



cc. Eyes one pair, far forward, com- 

 pound, fused in a common pigment 

 mass; gastric caeca seven pairs, 

 much branched. Placobdella. 



d. Caudal sucker with numerous 

 minute marginal papillae; size me- 

 dium or small. 



6. Moderately depressed, slender an- 

 teriorly; dorsal papillae usually in a 

 median and two paired series, small 

 but prominent and pointed. Placob- 

 della phalera. 



dd. Margin of caudal sucker smooth; 

 size large. 



7. Body very broad and much de- 

 pressed; dorsal papillae few, low and 

 smooth; integuments opaque; deeply 

 pigmented in a conspicuous pattern of 

 olive green and yellow. Placobdella 

 parasitica. 



