1851.] 225 



may elongate to one-half length of body, by l-200th in breadth. Lip may 

 expand into a circular disk, or be elongated into a triangular rostrum. 



Hah. Found in the pericardial cavity of Unio purpureas, U. nasutus, U. 

 radiatus, U. cariosus and Anadonta marginata. 



Planaria, Mailer. 



2. Planaria maculata. Leidy, Proc. Acad. 'Nat. Sci., Vol. 3, p. 251 ; 

 Diesing, Syst. Helm., Vol. 1, p. 205. i *; 



Length from 2i to 6 lines ; breadth i to 1 line. ' 



Hab. Everywhere in ditches near Philadelphia. (Found in great abundance 

 between the outer, decaying petioles and inner living ones of the leaves of the 

 Arum virginicsm^^rowing in profusion in ditches below the city.) 



3. Planaria ti^ncata, 7i. s. Body sublinear; posteriorly obtusely rounded; 

 anteriorly truncated, with the angles slightly prominent laterally. Blackish 

 white, translucent at margin, with a blackish streak down the back. Eyes two, 

 reniform, l-400th in. long by l-500th in. broad; l-200th in. apart. CEsophagus 

 simple, cylindrical, i line long. 



Length 3 to 5 lines; breadth i to i of a line. 



Hab. Found in a running rivulet in the vicinity of Newark, Delaware. 



4. Planaria (Typhlolepta ? Oersted,) fuliginosus, m. .r. Body oval, dilated ; 

 inferiorly flat ; superiorly moderately convex, fuliginous. Eyes none: in their 

 ordinary position a slightly greater accumulation of black pigment upon the upper 

 surface. Mouth inferior, a little posterior to the centre ; oesophagus simple, cylin- 

 drical, white, 1 line long by i line broad. 



Length S lines, breadth 4 lines. 



Hab. Rancocas Creek, near Pemberton, New Jersey. 



Anguillula, Oken. 



5. Anguillula longa, n. s. Body cylindrical, translucent, colorless. Mouth 

 round, buccal capsule inverted campanulate ; cesophagus and intestine cylindrical, 

 equal in diameter, the former l-25th in. long. 



Female, 2 to 3 lines long; anteriorly l-333d in. broad; middle l-285th in. Tail 

 narrow, acute, 1-1 11th to l-75th in. long from anus. 



Male, li to 2 lines long; posteriorly dilated, obtusely rounded, curved, with 

 three slight tubercular thickenings of the integument ventrally; l-285th in. 

 broad : at middle l-370th in. broad. Penis a curved spiculum, l-280th in. Ion"-. 



Hab.Yo\xn<l in very great abundance, wriggling above the surface of soft mud, 

 in stagnant ditches in the neighborhood of Philadelphia. 



6. Anguillula longicauda, n. s. 9 Body cylindrical, colorless, hyaline; an- 

 teriorly obtusely rounded; posteriorly attenuated, with a long, delicate, flexible, 

 subulate tail. Mouth without cirri ; cesophagus cylindrical, often with the ap- 

 pearance of a globular bulb at its lower end; intestine cylindrical; anus indis- 

 tinct. Generative apparatus ? 



Length of largest l-40th in. ; breadth 1 -1000th in.; length of tail l-200th in. 

 Smallest : length l-160th in. ; breadth l-2000th in. ; length of tail l-800th in. In 

 an individual 1-lOOth long, the cesophagus measured l-570th in. long. 



Hab. Found with Lyngbya muralis and other confervae about gutters and 

 water spouts in the city of Philadelphia. This species is very active in its 



80 



