THE NAUTILUS. 5 
respect, and specimens were found in places where the marl was less 
abundant, which seem to connect the two forms. 
Along the Lake Michigan shore, among the stones, Physa ancil- 
laria Say oceurred, exhibiting a very heavy, solid, opaque shell. 
The same form is found plentifully at Mackinac Island, and seems 
to be one of the most characteristic forms of the region. A heavy 
malleated form of Limnaea emarginata Say is associated with it in 
both localities. Limneea desidiosa Say and Physa integra Hald. 
were found plentifully in similar localities. 
In one of the smaller inland jakes near Charlevoix, the dark red 
form of Planorbis exacutus Say, recently distinguished as var. ru- 
bellus by Sterki, was found. ‘The typical form of the same species, 
as well as P. bicarinatus Say and parvus Say, occurred abundantly 
in the deep-water dredging at High Island. The great similarity 
of the Limneid fauna of northern Michigan to that of Maine was 
again manifested in the discovery, ina small mill-pond near Charle- 
voix, of the ecarinate form of P. bicarinatus recently distinguished 
by Mr. Pilsbry as var. aroostookensis. The only species of Aneylus 
met with was the A. parallelus Hald., which was common among the 
lily-pads in all the smaller lakes. Among the operculates there was 
little of special interest. Goniobasis livescens Mke., as usual in the 
lake region, was abundant everywhere, and in Lake Michigan was 
found in thirty feet of water. Valvata tricarinata Say and sincera 
Say were also abundant in deep water, and the latter species from 
High Island was unusually large and fine, and might be referred to 
the form described as JV. striata by Lewis. The Campolomae were 
also abundant. The slender northern form described by Lea as C. 
milesii, however, was found only in one lake on Beaver Island. The 
Lake Michigan form was C. decisa Say. The Amnicolae were ex- 
ceedingly abundant, the two larger forms A. limosa Say and lustrica 
Pils. occurring everywhere. A. grana Say was found at High 
Island only, as was also a single specimen of Bythinella obtusa Lea. 
One of the few disappointments met with was the failure to find the 
deep water form, A. sheldoni Pils., originally found in the deep 
water of Lake Michigan, at Racine, Wis. The only novelty among 
the Unionidae was the occurrence of Unio borealis Gray, in a small 
lake on Beaver Island. This is another addition to our fauna, and, 
I believe, the most western locality yet cited for the species, which, 
as Mr. C. T. Simpson, to whom I am indebted for the identification, 
suggests, is apparently only a form of Unio luteolus Lam. The 
