Regarding the range for Scaphella junonia, here's a recent discussion from Conch-L:

11/10/15. Patrice Bail:

"Are they reliable records of Scaphella juniona living in the Texas and east Louisiana waters? In the other way, does it cross through the Mississipi delta?"

Emilio Garcia:

"I have never collected Scaphella junonia in Texas. The farthest west was one specimen at 28º00.86'N, 92º27,56"W, which is still Louisiana. It has a very interesting orange coloration (i.e., S. j. form johnstoneae to the max) but it was collected dead."

John Tucker:

"S, junonia is included in Tunnell,et al, 2010. Encyclopedia of Texas Seashells, page 227, Unfortunately no collecting data is given for the illustrated specimen. There is also a report on the Gulf of Mexico put out by Texas A & M University which may have specific localities for these Scaphella. I do not have it at home but maybe can find it or you could e-mail Kevin Cummings at the Illinois Natural History Survey."

John Tucker:

"The shell auction site shellauction.net had three S. junonia from Mexico offered for sale in the last auction. Maybe Pat would like to look there for data? I cannot vouch for the accuracy."

Emilio Garcia:

"I am sure that the S. junonia from Mexico come from Yucatán, a well-known locality.

I think that Pat Bail wants reliable data on Scaphella junonia from Texas. Although Encyclopedia of Texas Seashells has it listed, the data is not-at-all reliable. I am one of the authors for the huge Texas A & M publication on the Gulf of Mexico biota of which you speak; however, we did not include Texas in the geographic distribution of S. junonia because we are yet to find reliable data."

Gustav Paulay:

"You can search records from databased museum collections that have joined in the iDigBio effort at: https://www.idigbio.org/portal/search.. The search returns a list of records, map of databased records, as well as images where those exists. When you search for Scaphella junonia, several Texan and Mexican records come up. Whether these are accurate would have to be of course evaluated for each specimen."

Patrice Bail:

"Hi Emilio and John,

The Mississippi delta is a natural biological barrier, almost impossible to cross for species at direct development and living in relatively clean waters such Volutidae. If a Texas population exists, the genetic exchange with the Florida/Alabama populations must be rare, and the genetic drift between them shall lead (in theory of course!) to obvious differences…That's why I open the question.

In fact, it seems that we have two populations only: the Florida/Alabama and the Yucatan, each populations having their own variants. Genus Scaphella is a true puzzle and the researcher needs aspirin to continue.."

Harry Lee:

"A puzzler indeed. I believe this species can be found offshore all the way N to Cape Hatteras. It certainly can be easily found off extreme NE FL outside the 15 fathom isobath.

While it may be difficult to find authentic TX records, offhand, I don't know of any zoogeographic barrier, including ocean currents, between Gulf of Campeche and TX.. However, the lack of a free-swimming veliger may put a damper such dispersal."

Vicky Wall:

"I recall Alta and Van VanLandingham finding junonias on Ocracoke Island. Janet Durand, who lived in Atlantic Beach, NC, found many junonias (13 in one day) at the Merriman Scallop Piles, in the 1990s."

Doug Shelton:

"I have 84 lots (more than 120 specimens) of Scaphella junonia (including various forms) ranging from North Carolina, throughout Florida, all the Gulf Coast including Louisiana and Texas south to Mexico and even Honduras. I have a high degree of certainty regarding at most of the records; certainly those from Louisiana and Texas.

Dr. Fabio Moretzsohn photographed some of my Texas material, but none of it was included in the Texas book. He was certainly aware of my Scaphella records from Texas."