OO THE NAUTILUS. 



and the mantle, only as a narrow ridge at the posterior end, 

 but broadening at the anterior, is also stained with red, darker 

 at the anterior end. Respiratory orifice, small, on the right 

 side, 2.5 mm. behind the anterior edge of the mantle, in the 

 center of the narrow mantle furrow which curves upward and 

 backward from the mantle edge. Total length 15 mm., width 

 3 mm. 



Internal rudimentary shell large, similar to that of P. caro- 

 linianus (Bosc), 6 mm. from the posterior extremity, and fast- 

 ened to that portion of the peritoneum directly above the 

 ovotestis. Approximately 2 mm. in diameter. 



The jaw ie similar to that of P. carolinianus in shape, and in 

 being but very slightly plicate. 



The radula, fig. 4, consists of about 150 rows of teeth hav- 

 ing a formula of 38-1-38. 



The one specimen received in sufficiently good condition to 

 examine the internal organs, was infested with two stages of 

 parasitic Trematoda. Twenty of these were found in the vicin- 

 ity of the lung, one beneath the shell, and one in the penis near 

 the retractor muscle. Therefore the reproductive organs in this 

 specimen may be in an abnormal condition, and on this ac- 

 count I refrain from figuring them. One of the most noticeable 

 differences is the complete absence of any glandular portion to 

 the cloaca, a large and constant character in P. carolinianus. 

 The ovotestis is nearly black, in sharp contrast to the light-col- 

 ored liver and other organs in the posterior portion of the 

 animal. 



Type M. C. Z. 48220. Hudson, Ohio, collected by Dr. R. 

 C. Rush. 



I have connected Dr. Rush's name with this species as a 

 slight recognition of the care and perseverance he has exercised 

 for many years in studying the life history of the land shells of 

 Ohio. 



Dr. Sterki (Proc. Ohio State Acad. Sci., 4, p. 877) describee 

 a closely related species as " Philomycus sp. pennsylvanicus 

 Pile.?" Dr. Sterki's species is similar to P. ruehi in that it 

 possesses a ' ' sole tinged with blood red ' ' but differs in being 

 twice as large (30 mm. long), and in the jaw having "a num- 



