Full Version: Costoanachis sparsa vs scutulata
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<i>Costoanachis scutulata</i> in Florida is often mistaken for <i>C. sparsa</i> for two reasons.  None of the most popular books (Abbott, Redfern, others) include <i>C. scutulata</i>.  Radwin (The family Columbellidae in the western Atlantic part IIa - the Pyreninae. The Veliger 20(2): 119-133. Oct. 1, 1977.) erroneously restricted <i>C. scutulata</i> to Bermuda and no one yet has questioned this error in the literature.  

Reeve's descrïptions of these two species is useless. His descrïptions were as follows:

<b><i>sparsa</i></b> - Shell fusiformly ovate, longitudinally finely ribbed, interstices cancellated, yellowish, sprinkled with chestnut dots and network, aperture small, lip varicose, notched at the upper part, denticulated within.

<b><i>scutulata</i></b> - Shell ovate, fulvous-chest-nut, promiscuously tessellated with white, whorls longitudinally ribbed, the last smooth, grooved at the base; aperture small, lip notched at the upper part,denticulated within.

However, Radwin did a pretty good job of describing the two and distinguishing between them.  Following are his descrïptions followed by some of my own observations, particularly the protoconch differences emphasized to me in communications from Dr. Harry Lee.

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Based upon review of material collected in the Florida Keys and the Bahamas [see Redfern's <i>C. sparsa</i> (#414), which is an apparently misidentified <i>C. scutulata</i> - note the extreme simitarity between Redfern's descrïption of his <i>sparsa</i> and Radwin's <i>scutulata</i>] is not restricted to Bermuda.  There are several differing characters between the two species.  However, the most reliable character that clearly distinguishes between <i>scutulata</i> and <i>sparse</i> is the protoconch.

<img src="" alt="" style="border:0" /> Palm Beach Inlet, FL.

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<img src="" alt="" style="border:0" /> Key Largo, Florida Keys.

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