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DESCRIPTIONS OF SEVE^r NEW SPECIES OF MARINE MOLLUSCA 

 FROM THE COLLECTION OF THE LATE ADMIRAL KEPPEL. 



By G. B. SowERBY, F.L.S. 



Head lOth March, 1905. 



Peuten Keppelianus. 



Testa semiglobosa, sequilateralis, insequivalvis ; auriculis latiusculis, 

 leviter insequalibus, fere rectangularibus. Valva dextra valde 

 rotundato-convexa, alba, maculis parviusculis, paucis, rosaceis, prope 

 umbonem ornata, concentrice undulatim subrugose laminata ; costis 

 circ. 14, latiusculis, angulatis, longitudinaliter trisulcatis, interstitiis 

 concavis. Valva sinistra concave depressa, aurantio-fusca, maculis 

 fuscis et albidis lineisque undulatis variegata, concentrice subtilissime 

 laminata ; costis mediocriter latis, longitudinaliter lii'atis, interstitiis 

 planulatis, lira angusta mediana interruptis. 



Lat. 86, alt. 78 mm. 



JIab. — Ascension Island (?). 



The shell has just the form of the Calif ornian P. dentafus, Sowerby, 

 which it resembles also in the dentate character of the margin, but the 

 difference, especially of the convex valve, is very apparent ; the ribs 

 are less numerous, and instead of being smooth and rounded, as in the 

 last-named species, they are angular and strongly grooved. 



My type is the only specimen of this species found in Admiral 

 Keppel's collection, and it was labelled Ascension Island. It happens, 

 as a rather curious coincidence, that just at this time two specimens 

 have reached the British Museum from the Cape Verd Islands. 

 The few labels with the late Admiral's shells were loose, and some of 

 them may possibly have been misplaced. It is therefore quite possible 

 that this Peden may have been collected at Sierra Leone, which is 

 much nearer to the Cape Verd Islands than Ascension. There were in 

 the collection no shells from the Cape Verd Islands, but many from 

 the other two localities mentioned. 



Tellina (Peeon^a) Ascensionis. Fig. 1. 



Testa oblonga, aequivalvis, fere sequilateralis, compressa, tenuis, 

 alba, epidermide tenui luteo-virente induta, nitida, fere laevis, 

 concentrice levissime striata, striis radiantibus vix conspicuis ; latus 

 anticum concentrice sulcatum, prope marginem subtilissime oblique 

 striatum ; latus posticum levissime angulatum, post angulum rugose 

 plicatum. Umbones central!, acuti, conjuucti, postice leviter iuclinati. 

 Margo dorsalis utrinque declivis, anticus leviter arcuatus, posticus 

 superne rectus, deinde convexus, ad extremitatem obtuse angulatus; 

 margo ventralis leviter arcuatus. Ligamentum crassum, longi- 

 usculum, nigro-fuscum. Dentes parvi, laterales nulli vel obsoleti. 

 Pagiua interna alba, roseo tincta. 



