162 BULLETIN OF THE BUREAU OF FISHERIES. 



distributed much as in Placobdella plialera. The position of the genital pores is quite as in Placobdellu, 

 the male orifice being situated between somites XI and XII and the female between the second and 

 third j)riniary annuli of XII. The anus is behind XXVI. 



The metameric .sensilla? are very obscure on tlie ventral but easily distinguished on the dorsal 

 surface; they present quite the arrangement typical of the family. Dorsal cutaneous papill* are also 

 well developed from somites XIII to XXV'I inclusive, and the larger ones may be traced faintly ante- 

 rior of the genital somites as far forward as VI As in A. inequiammlnla the strictly median series is 1j\ 

 far the most conspicuous and dominant one and is represented on the complete and typical somites liy 

 a large papilla on the annulus ^3 and a somewhat smaller one on 65. On XXIII these papilla; suddenly 

 become reduced greatly in size and by XXV have disappeared, while rather prominent dorso-median 

 papillaj are coincidently developed on each side and" continue to XXVI. Dorso-lateral papillse on 63 

 are nearly as constant but much smaller as far back as somite XXVI, and on many of the typical 

 somites a corresponding but still smaller papilla occurs in a more median position on hb. It will be 

 noticed that in the arrangement of the papilla", as in so many other characters, this species stands 

 between -1. inequiannulatn and Phirohil,lhi iiimili/rni and F. phalera. 



In the manner of subdivision ni t\ jiical s niiitrs into annuli this species closely follows the type of 

 the genus. The first primary annulus i al i i-^ always much smaller than «2 or «3, and Is completely 

 sulidivided into two short equal or nearly equal rings (61 and 62); the primary neural annulus (a2) is 

 divided into a larger anterior ring (63), which bears the papillse and metameric sensilhe and a much 

 smaller posterior ring (64); the third primary annulus (a3) is similar in size and mode of subdivision 

 to tlie second, and its larger anterior annulus (6.5) bears the papillse, while the small 66 is naked. 

 Somites VII to XXII are complete, although a3 is already much smaller than o2 even on XXI, and on 

 XXII the furrow 6.5/66 is not quite complete. On XXIII all secondary furrows are nearly absent and 

 a3 is a small simple ring. On XXIV al is barely separated from <i2; XXV and XXVI are typically 

 biannulate, and several obscure annuli in the caudal pedicle represent postanal somites. The annula- 

 tion of the anterior incomplete somites is very clear, and shows that elaboration has progressed farthiT 

 in this species than in .4. inequianmdata. Somite VI has al undivided, V is triannulate with a2 soim-- 

 what enlarged, IV is biannulate with the furrow al/a2 indicated, III is a broad, practically undivided 

 annulus, and II and I are simple and undivided. (See figs. 1 and 2.) 



A few features of the internal anatomy may be noted. The probocis is slender and, as retracted 

 in this specimen, reaches from XI to VIII. The salivary glands are of the diffuse type and open into 

 the oesophagus in X or XI; they are greatly developed and densely packed by the sides of the alimen- 

 tary canal as far forward as the anterior part of somite VIII. Exactly similar glands are develoi)ed 

 in large numbers along the sides of the body to somite XXIV, but it is impossible to determine 

 definitely in the entire leech to what extent these are salivary or clitellar and cutaneous glands. There 

 are seven pairs of well-developed branched gastric cieca arising in somites XIII to XIX, inclusive, 

 arranged as in PlucohdeUa, though not so large and completely branched as in the broad flat species of that 

 genus. The first pair have slender anterior lobes which reach forward by the sides of the reproductixe 

 organs to the anterior end of XII; the seventh pair reach backward beside the intestine to XXIII, 

 with five lateral lobes in somites XIX to XXIII. The narrow and posteriorly somewhat tortuous 

 intestine bears the usual four pairs of cseca crowded into three somites (XX to XXII). Although con- 

 forming to the general type of the reproductive organs of Placobdella, the male afferent ducts are more 

 elongated and slender than in most species and reach to a sperm sac situated on the boundary between 

 XII and XIII, being thus less compact and more open in arrangement than in most species of Plaroh- 

 della. The greater part of the sinus system was worked out and found to conform in most respects to 

 what is found in the Glossiphonida; generally, one important characteristic being that the submargi- 

 nal circular sinus of the posterior sucker is connected with the axial sinus behind the anus by 1.5 or 

 16 radiating canals. The type specimen (no. 5228, V. S. National Museum) is from station 346a, Lon-r 

 Point, Canada, August 18, 1899, and was taken with P. parasitica from a snapping turtle. The colors 

 are lost in alcohol. 



