f^x/S«i 



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810 THE MARaUIS 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 stjbflaa'tjm, 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 rotun- 

 data, transversim sulcata. Apertura leviter obliqua, tumore cir- 

 cumdata ; septo haud elevato, bimamillato, sen mamillato- 

 ungulato ; margine laterali undulato, paululo convexo, fere 

 piano decollations parallelo. 

 Length of entire shell 25 mm., length of the adult part 1*8 mm. 

 Breadth 0'4 mm. 



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 the place where decollation was about to take place. Such 

 specimens are occasionally to be met with, and are very interesting. 

 The species belongs to the pretty numerous group of smooth 

 Cceca, 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 Fouds 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. 



ft '\- 10. CAECUM 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 contractu, septo subplanato, 



parum expresso, vice conspicuo. 



Length 1'9 mm. to 2 mm. Breadth - 4 mm. 



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. 



