1910.] NATURAL SCIENCES OF PHILADELPHIA. 505 



This race differs from sipunculala only in color, which may or may 

 not be a constant racial character. 

 P. o. erecta (Mouss.). 



Helix erecta Mousson, nialak. Blatter, xxi, 1873, p. 3. Pfeiffer, Novit. 

 Conch., Ill, p. 116, pi. 127, figs. 1-3 (Bogota). 



Blackish-brown, identical with subplanata except for its smaller 

 size and greater elevation, alt. 13, diam. 30 mm. 



P. o. orthorhinus n subsp. PI XXXVII. fig*. 1, 2, 3. 4. 



The shell is dark brown, often blackish at the keel, and differs 

 from L. otis in having the inner end of the peristome less recurved into 

 the umbilical cavity, and the outer end much less deeply channelled, 

 scarcely or not recurved; the gutter above the keel and the upturned 

 flange of the latter are less emphatic. 



Alt. 19, diam. 42 nun.; 5 whorls. 



Types No. 101,308, A. N. S. P., from a small clearing between 

 Tabernillo and San Pablo, on the new line of the Panama R. R., 

 collected by Dr. Amos P. Brown, April, 1910. The same form is 

 in the collection of the Academy from Gorgona, also on the Panama 

 R. R. One of the specimens from Gorgona has been figured in the 

 Manual of Conchology, V, pi. 64, figs. 14-16. 



A specimen somewhat abnormally elevated measures alt. 23.5, 

 diam. 45 mm. 



In connection with the preceding it may be well to consider the 

 following South American species. 



Pleurodonte (Labyrinthus) plicata (Born). 



Helix plicata Born, Testacea musei Ca-sarei Vindobonensis, 1780, p. 368 

 referring to Knorr, Vergniigen der Augen und des Gemiiths, 1771, pt. V, 

 pi. 26, fig. 5 (India occidentals ). 



Caracolla hydiana Lea, Obs. Genus Unio, ii, 1838, p. 98, pi. 23, fig. 73. 

 (Near Puerto Cabello [Venezuela].) 



This species is well distinguished from P. otis by its more open 

 aperture and smaller basal teeth, as pointed out in the Manual of 

 Conchology. Some specimens in the series before me agree closely 

 with the figure referred to by Porn, others with Lea's figure. It is 

 apparently an abundant snail around Puerto Cabello, Venezuela, found 

 also at Chorini and Caraccas, and one specimen received from Des- 

 hayes is labelled Carthagena, X. G. There is no trustworthy record 

 of plicata from Panama. I cannot agree with Prof, von Martens that 

 plicata and hydiana (hydeana Martens) are distinct species. A careful 

 stud}' of numerous specimens shows that they are identical. 



A very small race, alt. 11.5, diam. 31 mm., from Marmato, Colom- 

 bia, has been figured in the Manual of Conchology V, p. .164, pi. 63, 

 figs. 6. 7, 8. It may be called Pleurodonte plicata marmatensis. 



