OCR Text |
Show 810 THE MARQUIS DE FOLIN ON THE [Dec. 16, Compared with the original types, the 'Challenger' specimens have the transverse striations stronger, more regular, and more prominent, but they certainly belong to this species. 9. CECUM SUBFLAVUM, n. sp. St. 186. Sept. 8, 1874. Flinders Passage, Cape York. 7 fms. One specimen. Testa minuta, subcylindrica, paulo arcuata, primum albida, dein subflava, nitida, strigis irregularibus plus minusve expressis, transversim cincta, aperturam versus tumida ; inflatio rotundato, transversim sulcata. Apertura leviter obliqua, tumore cir-cumdata; septo haud elevato, bimamillato, seu mamillato-ungulato; margine laterali undulato, paululo convexo, fere piano decollationis parallelo. Length of entire shell 2*5 mm., length of the adult part 1*8 m m. Breadth 0*4 m m. In this specimen the adolescent shell is still united to the full-grown adult, whose septum can be recognized within, through the thin walls of the younger shell. A slight contraction of the tube indicates tbe place where decollation was about to take place. Such specimens are occasionally to be met with, and are very interesting. The species belongs to tbe pretty numerous group of smooth Ceeca, all more or less nearly connected. Among these may be mentioned in particular C. auriculatum, C, bimamillatum, C. circumvolutum, C. massiliense, C. modestum, C. strigosum (see 'Les Fonds de la Mer') ; but from them all this species differs in the mouth or in the septum. In colour it is whitish near the apex and slightly yellowish towards the mouth. It is strongly but irregularly striated transversely. Near the mouth, which is little oblique, there is a rounded transversely furrowed varix bevelled off to a thin inner edge. The septum is bimamillated, having a slightly larger and higher swelling on the side which lies near the concave curve of the shell. 10. CECUM SUCCINEUM, n. sp. St. 186. Sept. 8, 1874. Flinders Passage, Cape York. 7 fms. Nine specimens. Testa minuta, subcylindrica, parum elongata, arcuata, flava vel albida, subopaca, nitidissima, Icevis sed subannulata, aperturam versus dilatata, annulo lato, rotundato, prominente terminata. Apertura paululo obliqua, haud contracta, septo subplanato, parum expresso, vix conspicuo. Length 1*9 m m . to 2 m m . Breadth 0*4 m m. This species is nearly cylindrical, a good deal curved, rather long, amber-coloured or whitish or yellowish, very glossy, nearly opaque. In some lights it looks as if girt by a series of very small rings ; but there is no real swelling nor grooving, and the appearance of rings is probably only some effect of reflection in connexion with the texture of the shell. There is a broad and high ring round the mouth. |