RANDOM NOTES ON NATURAL HISTORY. 



87 



1*26. Physa Ancillaria, Say. 



Syns: 

 ■ Physa obesa,DeKay, N. Y., Moll., 1843. 



"Shell ovate-globose, pale yellowish; 

 whorls four, rapidh' attenuated ; spire trun- 

 cate, ver^' little elevated above the general 

 curve of the shell ; suture not impressed ; 

 aperture rounded in front, seven-eighths the 

 length of the shell. Animal bright lemon 

 color. It inhabits from New England to 

 Louisiana, and is ver}' plenty in some 

 localities, though not abuittlant in Rhode 

 Island." 



It was described by Say in the Journ. 

 Acad. Nat. Sci., V., 124, 1825. It attains 

 a length of over one-half inch by seven- 

 twentieths in breadth. It becomes stout 

 and thick by age, and the reddish rib 

 along the outer lip and the enamel on the 

 columella becomes quite hard an<l solid. 



All the species of Physa and Aplexa are 

 left-handed, /. e., they have the aperture on 

 the left side of the shell and are called sin- 

 istral, in distinction from all other fresh 

 water shells inhabiting America which are 

 dextral or right-handed. 



127. Physa Heterostkopua, Say. 



The S3'non3'my of this species is terribly 

 mixed. Our conservative friends who hate 

 to drop a word which no longer has a 

 meaning, but who would still be contented 

 to call spiral shells, land, fresh water, or 

 marine, of any shape or style, by the name 

 of Helix, might, perhaps, agree with Mr. 

 Binne}', who in Fresh Water Shells of 

 North America adds about a dozen dis- 

 tinct species of shells to the alread}' numer- 

 ous synonym}'^ of P. heterostropha. 



Say first described this shell as Lymnoea 

 heterostropha in Nicholson's Encyclopcedia 

 in 1817, but changed the name to Physa 

 in 1821 in Joar. Acad. Nat. Sci., II., 

 172. "Shells sinistral, sub-ovate; color 

 yellowish, chestnut, or blackish ; whorls 

 four, — the first large, the others very small, 

 — terminating abruptlv in an acute apex; 

 a[)erture oval, three-quarters the length of 

 tlie shell, within of a pearly lustre, often 

 blackish ; lip thickened on the inside and 

 tinged with a dull red." 



This species is abundant ever3'wliere in 

 ditches, ponds, and rivers all over North 

 America, north of Mexico. It resembles 

 P. ancillaria but is distinguished from it by 

 the following characteristics : The animal 



of heterostropha is olivaceous, surface very 

 smooth and silky ; ancillaria is bright lemon 

 color. The shell of ancillaria has a shorter 

 spire, a more angular outline, the suture is 

 more closel}- appressed to the whorls, and 

 the surface of tlie shell is perfectlj' smooth. 

 The surface of heterostropha under a glass, 

 is covered with waved, revolving and longi- 

 tudinal lines. It attains a larger size than 

 ancillaria, and when fully grown, the lip is 

 thickened and the broad, pearl}' layer of 

 enamel on the columella has a very promi- 

 nent fold. 



{To be continued.) 



Hyalinia Wheatleyii, Bland. 



In chapter XXIX., page 47, of Random 

 Notes, June, 1886, I published an error in 

 describing species 101 of Rhode Island 

 shells. This chapter was devoted entirely 

 to the new species found by Mr. John H. 

 Thomson, of New Bedford, Mass., which 

 had never been seen b^' me, or hitherto 

 found in our state. 



This species was called Mesodon wheat- 

 leyii, Bland, a species found in North Car- 

 olina, and described by Mr. Bland, in Ann. 

 N. Y. Lye, VII., 118, 1860. I supposed 

 this to be the shell meant by Mr. Thomson, 

 and not knowing that Mr. Bland had given 

 two Helices the same specific name, I 

 reprinted Bland's description of Mesodon 

 Wheatleyii. I have since been informed by 

 Mr. Thomson, that this was not the shell 

 discovered in Tiverton, but on the contrary 

 a very different one, namely, Hyalinia 

 Wheatleyii, a small shell also found in 

 Georgia, Tennessee, and North Carolina, 

 and described by Mr. Bland in 1883. I am 

 happy to correct the error at once, and be- 

 low is the true description of the shell in 

 question : 



101. Hyalinia Wheati.eyii, Bland. 



"Shell umbilicated, depressed, thin, shin- 

 ing, pellucid, brownish horn color, finely 

 striated ; spire sub-planulate, suture slightly 

 impressed ; whorls little convex, the last 

 rapidly increasing, more convex on the base, 

 scarcely descending at the aperture ; umbil- 

 icus rather wide, margins of peristomes 

 approximating, joined by a thin callus." 

 Diameter one-fifth of an inch. 



It resembles in some respects H. electrina, 



Binne\'ana, and arborea. 



H. F. Carpenter. 



