168 WHEELER. [VoL. IX. 
found attached to the Horse-shoe Crab. Length, a quarter of 
an inch.” 
The generic position of this species was regarded as doubt- 
ful, «the genus Vortex not being as yet well circumscribed.” 
A year later Leidy (51) gave the following description of a 
planarian from Lzmalus : — 
‘“ PLANARIA, Miiller. 
Subgenus nov. Bdelloura} 
Characters same as Planaria, without tentacule, and the 
posterior extremity of the body separated by a constriction 
serving as a disc of attachment. 
5. BDELLOURA PARASITICA, #. SP. 
Body milk-white, with a faint yellowish intestine showing 
through the translucent integument, smooth, thin, lanceolate, 
or spatulate; anteriorly narrowed, obtuse ; lateral margins, 
thin, undulating ; constricted portion posteriorly truncated, 
nearly as broad as the middle of the body. Eyes two, 
reniform. C&sophagus simple, cylindrical, campanulate when 
protruded. 
Length from 3 to Io lines ; breadth 2-5 to 234 lines. The 
longest may contract to 6 lines by 3% lines. 
Habitation. — Parasitic upon the King Crab, Polyphemus 
occidentalis, Lam.” 
The year following, Girard (52), while remarking on Fovza, 
says : “ Vortex candida, described at the same time, has been 
described since by Dr. Leidy under the name of Bdelloura 
parasitica. The genus Bdelloura I adopt, but the species must 
retain its prior name and be called B. candida, Girard.” 
Notwithstanding this identification of B. parasitica with 
Vortex candida, Stimpson in his Prodromus (58) retained 
Leidy’s specific name. 
These early descriptions were unknown to v. Graff, who in 
1879 again described a Triclad from Limulus as Planaria 
1 B5e\Xa, a leech; ovpa, tail; because the animal adheres by the tail like a leech. 
