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Show 808 THE MARQUIS D E FOLIN O N T H E ^vec. 10, appearances of belonging to the family of the Csecidse. Their form is very peculiar: obviously they have lost the embryouic shell, and the opening thus made has been closed by a septum; but, unlike the case in Ceecum, only a single decollation has taken place here, leaving the shell acutely conical. On this feature the new genus is founded, which I have dedicated to the Reverend Robert Boog Watson. 3. WATSONIA ELEGANS, n. sp. St. 186. Sept. 8, 1874. Lat. 10° 30' S., long. 142° 18' E., Wednesday Island, Cape York. 8 fms. Coral-sand. Surface temperature 77°*2 F. Three specimens. Testa adulta, tubularis, conica, leviter biarcuata, subflava, annulis regularibus, rotundatis, valde obliquis, minimis, expressis, crebris, elegantissime cincta; apertura valde annulo lato crasso valdeprominente circumdata. Length 2*5 mm. Breadth 0*5 mm. This very remarkable and elegant form is extremely conical. It starts with a rather regular curve, and towards the mouth bends suddenly in the same direction as the very oblique aperture. It is yellowish glossy and very beautifully ornamented with numerous small, transverse, oblique rings slightly expressed, but well rounded, and though close-set yet well defined. The very oblique mouth is strengthened by a large and very prominent riiag, which indicates the adult condition of the shell. This fact of the shells being full-grown implies that no further decollation was to take place, while the fineness of the pointed apex indicates that only one has occurred already. The septum of the apex is smooth, with a minute, scarce visible mamil-lation in one specimen, which is even less marked on the second. The third is broken. All appearances point to tbe Csecidse as the true position of this beautiful and interesting little shell; but even should this prove a mistake, it will still constitute in any case a remarkable genus. 4. CAECUM LINEICINCTUM, n. Sp. St. 24. March 25, 1873. Lat. 18° 38' 30" N „ long. 65° 5' 30" W . Off Culebra Island, St. Thomas, Danish West Indies. 390 fms. Coral-mud. One specimen. Testa subcylindrica, parum arcuata, albida, subopaca, subleevis, aperturam versus lineis transversis cincta. Apertura 1 mucronato, leviter circumdato. Length 2*5 mm. Breadth 0*7 mm. The solitary specimen of this species is in bad condition ; but the shell is obviously glossy, nearly opaque, whitish and almost smooth, with a few strong transverse lines like minute rings towards the mouth, which is broken. The mucronated septum has possibly been much larger; for it seems eroded. Like all dactyliform septa it is surrounded by a portion of the tube which projects so as to protect it. It is the first smooth or nearly smooth Ceecum I have |