156 BULLETIN OF THE BUREAU OF FISHERIES. 



for .some of our species. Owing to the considerable attention that leeches of this 

 family from the eastern and northern states have recently' received, it is not sur- 

 prising that but a single species has been added to those previous!}' known, and it 

 has not been thought necessary to include detailed descriptions of any others, though 

 a key is added which will serve for typical examples, at least. Complete descrip- 

 tions with figures, some of them colored, will be found in a report on the leeches of 

 Minnesota prepared by the writer and soon to be published by the Natural History 

 Survej' of Minnesota. Some additional information will be found in Castle, North 

 American Fresh- water Rhynchobdellidffi (Bulletin Museum Comparative Zoology, 

 l'.)O(t), and Moore, Hirudinea of Illinois (Bulletin Illinois State Laboratory of Natural 

 History. 1901), and in the papers therein cited. A full catalogue of the localities 

 at which each species was taken is given, the station number l)eing included in 

 parentheses and followed by such data as the labels afford. 



Key ti> the .ijiecies of leerhes conlnnied in this collection. 



I. Mouth a small pore in the disk of the anterior sucker from which a muscular pharyngeal ])robo8cis 

 may be protruded; eyes all situated close to the middle line, 

 a. Complete somites of 3 annuli, with the secondary furrows altogether wanting or only very slightl}- 

 developed. 

 6. Genital pores separated by a single annulus; eyes simple, 1 pair, widely separated. 

 c. A brown chitinoid plate and underlying gland situated on the dorsum of somite VIII. "" 

 d. Body capable of great extension; no I'.istinct cutaneous papillae; color pale, pink, gray,%r 

 brownish; gastric ciBca small and variable in number, never more than 6 pairs. 



Glossiphonia stagnalis (p. 157). 

 cc. No nuchal gland nor plate. 



e. Body greatly elongated, slender and nearly terete, without cutaneous papillae and very 

 transparent, owing to the nearly complete absence of pigment; gastric ca;caonly 1 pair. 



Glossiphonia nepfieloidea (p. 158). 



ee. Body relatively broad and flat; cutaneous papilUe absent or in 1 to 5 rows, which may 



be very small or very large and often double; deeply pigmented, usually longitudinally 



striped or with metameric white spots on the neural annuli; gastric ceeca always 6 



pairs, of moderate size and simple form Glossiphonia fusca ( p. 158) . 



66. Genital pores separated by 1 annulus; 3 pairs of simple eyes grouped in twos in a more or less 

 triangular figure. 



/. Body very thin, broad, and flat; no distinct cutaneous papilte; integument transparent 

 and pigment, nearly absent; gastric cseca 6 pairs, of moderate size and nearly or quite 



unbranched Glossiphonia heteroclila (p. 159). 



666. Genital pores separated by 2 annuli; 3 pairs of simple eyes in 2 nearly parallel rows. 



(/. Body relatively broad and short; cutaneous papillse low and rounded, no median 

 series; usually deeply pigmented and having a pair of narrow dark longitudinal lines 

 reaching from the eyes to the posterior end; gastric cseca 7 pairs, of moderate size 



and slightly branched Glossiphonia complanata (p. 159 ) . 



6666. Genital pores separated by 2 annuli; a single pair of compound eyes more or less completel\- 

 united in a single pigment mass; gastric caeca 7 pairs, of large size and much branched; 

 salivary glands compact. 



h. Somites I to V distinctly widened to form a discoid "head." 



I. Somites I and II biannulate; dorsum marked by 3 strong papillated keels. 



Placohdella montifera (p. 160). 

 hh. Anterior suuiites (I to Y) not especially widened. 



j. Body very much depressed; the cutaneous papillae low and smooth; integu- 

 ments opaque, and the color a conspicuous pattern of some shade of olive 



