THE NAUTILUS. 



been prepared in advance of the formal report of the summer's 

 work. 



Owing to the sandy nature of the soil, so characteristic of that 

 portion of the State, and the long-continued drought which pre- 

 vailed during last summer, terrestrial mollusks were not so numer- 

 ous, either in species or individuals, as might naturally have been ex- 

 pected. The characteristic feature was the occurrence of many spe- 

 cies, especially of the Zonitidae, peculiar to the northern region. Thus 

 Zonites ferreus Mse., blnneyanus Mse., and exirjuus Stiiup., Vitrina 

 limpida Ged., and Helix harpa Say, are not found in the southern 

 part of the State. Palula asteriscus Mse. and Strobilops virgo Pils., 

 also northern forms, were interesting additions to our fauna. The 

 local and rare (in this State) Helix sayii Binu.,an essentially north- 

 ern form, also occurred, indicating its probable range across the north- 

 ern part of the State, as all the examples heretofore known to the 

 writer have been from the counties bordering on Lake Huron. A 

 few specimens of the albino variety of Patula alter nata Say, were 

 found associating with the typical form. Two forms of Helix albo- 

 labris Say were noted, occurring bide by side, the one quite typical 

 in shape and color, but rather below the average size and with a 

 very thick and broadly-reflected lip ; the other larger and much in- 

 flated, with a thin, dark purplish brown shell, having the narrowly 

 reflected lip more or less deeply tinged with purple ; a very beauti- 

 ful form, not seen elsewhere. The only Pupa found was P. con- 

 li-iif/it Say, while Vertigo was represented by four forms, V. ovata 

 Say, bollesiana Mse., ventricosa elatior Sterki, and pentodon Say. 

 In addition to the universally-distributed Suceinea obliqua Say and, 

 avava Say, was found the elongated form of S. ovalis Old., com- 

 mon in the northern part of the State, which has been doubtfully 

 referred to the S. higginsi Bid. (see NAUTILUS, VII, p. 127). In 

 all, thirty-one species of land-snails were found, of which two were 

 new to the fauna of the State. 



Among the fresh-water pulmonates, many interested forms oc- 

 curred. The most noteworthy of them was a single example of a 

 deep water form of Limncea xtagnalits L., dredged from ten metres 

 depth in Lake Michigan, at High Island Harbor in the Beaver 

 Islands. It is about 23 mm. in length, exceedingly fragile, of a pure 

 translucent white, and, though somewhat larger and differently pro- 

 portioned, appears to be analogous to the var. Uottnica of Clessin 

 from Sweden. At the same locality occured a small globose form 



