190 BULLETIiN ISl, UNITEO STATES NIATIIQINIAL MUSIETJM 



APEBOSTOMA (INCIDOSTOMA) KOBELTI. new species 



Plate 25, Figxjbes 7-9 



1912. Neooyclotus pergrandis var. Kobelt, Martini-Chemnitz Conchylien Cabinet, 

 vol. 1, sect. 19, pt. 3, p. 903, pi. 140, figs. 1-3. 



We have not seen anything that would satisfy Kobelt's description 

 and figure and therefore give a translation of his description of 

 Neocyclotus pergrandis var. : 



A magnificent specimen in the Berlin Museum, which Professor 

 Thiele has permitted me to see, leads me to refer again to Neocyclotus 

 pergrandis., * * * ^^ highest development of which is probably 

 represented by this specimen. It is somewhat larger than the speci- 

 mens which I figured from the collection of the Senckenbergische 

 Museum. The greatest diameter is 57 mm. and the least diameter, 46 ; 

 height, 28 mm. Its conservation is splendid, its sheen and coloration 

 faultless. The suture is materially more strongly impressed and this 

 character can be followed to the third last whorl. The whorls there- 

 fore project only slightly. The last whorl has a pronounced periph- 

 eral keel, which does not show in pergrandis. This forms the boundary 

 between the yellowish white peripheral band and the blackish brown 

 infraperipheral zone. About 2 cm. behind the peristome, which is 

 decidedly deflected, the siphonlike auricle arises. This measures 

 13-14 mm. in diameter at the base and is appressed to the preceding 

 whorl and projects above this for half its length. The interior of 

 the siphonlike perforation is covered with a pearly callus and forms 

 an open aperture separated from the preceding turn by a narrow 

 slit. The siphonal puncture measures about 4r-5 mm. long. The open- 

 ing to it is observable only when one looks at it obliquely from below. 

 Between the peristome and the tubular structure the last whorl is 

 free from the preceding turn and decurrent, that is, overhanging 

 the aperture. The breadth of the aperture is 25 mm., and the height 

 obliquely measures about the same; vertically it is somewhat less. 

 The interior of the aperture is livid white, shining, through which the 

 infraperipheral band shines bluish. 



The specimen described comes from Cundinamarica, between Bo- 

 jaca and Tene, on the Lake of Tedropalo, Colombia, and bears the 

 catalog number 37582. 



In this species the siphonal development at the posterior angle is 

 larger and stronger than in any other form we have seen. It also 

 appears to lack the malleation described for A. (/.) mdlleatunn and 

 A. (/.) pergrandis (Kobelt). 



Kobelt's figure yields the following measurements; Wliorls, 4.5; 

 height, 26.8 mm. ; greater diameter, 54 mm. ; lesser diameter, 39 mm. 

 Height of aperture, 18.7 mm. ; diameter, 24 mm. 



