THE NAUTILUS. 71 



Modulus modulus L., a few poor specimens noticed. 



Littorina nebulosa Lam., var. columellaris Orbigny. A few were 

 found on logs along the beach, but it is common on the jetties. Dr. 

 Dall referred it to L. jiava. Pilsbry says " L. Jlava is very thick 

 inside the lip, exactly like irrorata. It resembles nebulosa in color, 

 but is evidently a distinct species close to irrorata. I have never 

 seen L. Jlava from north or west of Trinidad." 



Littorina ziczac Dillwyn., very numerous on the jetties. 



Cassis inflata Shaw, two young and dead. 



Nerita praecognita C. B. Adams, three on the rocks of the jetty. 



Neritina lineolata Lam. Plentiful in low places along the river 

 and young ones were found on the gulf side of the jetties. 



Neritina virginea L., a few were found with lineolata on one jetty. 



Solarium granulatum Lam., two dead specimens. 



Fissurella alternata Say, a few dead ones. 



Vermicularia spirata Phil., young and dead. 



Melampus coffea L., a few immature specimens. 



Melampus floridanus Shuttl. Only a few specimens of this small 

 species were found. Dr. Dall referred them to young Tralia cingu- 

 lata Binney. 



HELICINIDjE. 



Helicina chrysocheila Binney. Tampico and Valles. Scattering 

 specimens were found over considerable territory. The species is 

 very variable in color. Dead specimens were numerous in some 

 places. 



Helicina flavida Mke. This species was found only in the drift 

 on the river bank, mostly dead. 



Schasicheila hidalgoana Dall. El Abra, on the mountain side 

 with Opeas and Holospira, only 3 taken. 



IIKLICIDjE. 



Trichodiscina coactiliata Fer. Tampico, in drift. 

 Praticolella griseola Pfr. This was the most widely distributed 

 species found. It seems to prefer the open fields and pastures. 

 Polygyra martensiana Pils. Tampico and Valles. 

 Polygyra oppilata Moric. Tampico and Valles. 

 Polygyra implicata Beck. Tampico. 

 Polygyra polita Pilsbry and Ilinkley. Tampico. 

 Polygyra aulacomphala Pils. and Hinkley. Tampico. 



