1851.] 209 



ASTACOBDELLA, Vallot. 



13. AsTACOBDELLA Philadelphica, 71. s. Body whitish, translucent, sides 

 nearly parallel, a little broader posteriorly, 16 alternately broad and narrow 

 segments exclusive of head and posterior end. Head campanulate, terminated 

 by a circular or elliptical crenated lip fringed with very minute stiff hairs, 

 l-2000th in. long. Acetabulum circular, 1-Gth to J line in diameter. Mouth 

 elliptical. Dental plates brown, nearly equal, forming an isoseoles triangle, 

 with the base longest and attached. Apex of superior plate ending in a sharp 

 conical point, with several very minute denticulations on each side. Apex of 

 inferior plate bifurcated into two joints, with two minute denticulations on each 

 side. Stomach capacious, nearly filling the anterior 8 alternately broad and 

 narrow segments posterior to the head. Anus dorsal, l-5th of a line from the 

 acetabulum. Generative aperture ventral, anterior to the anal aperture. 



Length 1 to 4 lines; breadth l-6th to i line. Head l-6th to J line long. 

 Ovum attached by a pedicle, with an operculum pointed at summit. From base 

 of attachment to point of opercle, l-5th line. Length of body of ovum l-6th 

 line, breadth l-8th line. 



Hab. Found frequently in numbers from one to several dozen upon any part 

 of the exterior of the body of Astacus Bartonii, FcA., but more especially upon 

 the inferior surface and the branchiae. 



Malacobdella, Blainville. 



14. Malacobdella grossa, Blainville. Hirudo grossa Midler, Zool. Dan. 

 Malacobdella grossa, Blainville, Die. Sc. Nat. xlviii. 270 ; Moquin-Tmidon^ 

 Monag. Hirud. ; Diesing Syst. Helm. ; Phylline grossa, Johnston, Lend. Mag. 

 Nat. Hist. lii. 610. 



Body yellowish white, compressed pyriform, oblong, or elliptical. Integu- 

 ment translucent. Acetabulum yellowish, circular, I to 2i or 3 lines in diame- 

 ter. Protractile proboscis cylindrical, from i to 3 lines long. Intestine tortuous. 

 Ovaries upon each side iron grey. 



Length from 2 lines to 1 inch, occasionally H inches; breadth from J a line 

 to 5 or even 7 lines. 



Hab. Found frequently, usually singly, adhering to the mantle of Venus 

 mercenaria, Lin. and Venus praeparca. Say. 



On motion of Dr. Zantzinger, it was Resolved, that a committee con- 

 sisting of Mr. George Ord,Dr. J. C. Fisher, Dr. Leidy,and Mr. Powel, 

 be appointed to act in conjunction with the Entomological Committee, 

 to make observations on the Cicada septendecim now making its appear- 

 ance in this section of country. 



ELECTION. 



Dr. Franklin B. Hough, of St. LawrenceCo,,New York, was elected 

 a Correspondent of the Academy. 



28 



