207 



SCIENCE-GOSSIP. 



corneous brown, composed of seven closely-coiled, 

 slowly increasing, rounded whorls, the last of which 

 descends a little anteriorly. It is finely striated 

 and decussated by microscopic spiral sculpture, 

 scarcely visibly on the earlier whorls, but more 

 apparent below. The peristome is white, a little 

 thickened and reflexed ; the parietal callus has a 

 raised flexuous ridge separated, above and below, 

 from the margins of the peristome. The parietal 

 armature consists of a strong vertical plate, a little 

 deflected posteriorly at the lower extremity, where 

 it terminates in a short strong ridge ; it has also a 

 short support a little higher up on the anterior side, 

 and another short ridge on the posterior side at the 

 upper extremity. Below this plate is a free thin 

 horizontal fold, and a little above the middle of 

 the plate, a short distance from it, rises a strong 

 horizontal plate, which runs parallel with the 

 whorl, and descends a little at the aperture, where 

 it is united with the raised ridge of the parietal 

 callus (see figs. 33a and b, which shows the shell 

 with part of the outer wall removed). The palatal 

 armature consists of: first, a thin bilobed hori- 



zontal fold near the suture ; secondly, a stronger 

 horizontal fold, with a small denticle at its 

 posterior termination (between these folds, in a 

 line with their posterior terminations, is a 

 minute denticle) ; thirdly, a horizontal fold, 

 descending a little posteriorly, where it is 

 slightly notched ; fourthly, a similar horizontal 

 fold, deflected posteriorly, finally slightly raised 

 and notched ; fifthly, a shorter but stronger hori- 

 zontal fold with the posterior end more strongly 

 deflected and also slightly notched ; sixthly, a 

 thinner but longer horizontal fold near the lower 

 suture, attenuated anteriorly (see fig. 33;^, which 

 shows the inner side of the outer wall with its 

 palatal folds). Between the posterior terminations 

 of the fifth and sixth folds is found a very slight 

 thin fold extending much further posteriorly than 

 the main folds ; this may prove not to be constant ; 

 it is not mentioned by Mr. Godwin-Austen in 

 his description. The specimen figured is in 

 Mr. Ponsonby's collection, and measures — major 

 diameter, 11 -5 millimetres, minor diameter, 10 

 millimetres, axis, 55 millimetres. 



(To be continued.) • 



