60 LAND AND FRESHWATER 



lost by being broken ; these darts are extremely brittle and most 

 difficult to work out entire, they must frequently be broken off in 

 the living animal or be in process of re-formation. Thus Hg. 10 

 does not look quite complete. They are not always to be found 

 near the vagina, but halfway up the sheath of the amatorial organ. 

 The series of ridges in the penis of D. inter me> Hits indicate, I think, 

 a spermatophore in process of formation. 



Family ZONITID^. 



Subfamily Durgellin^, 



Genus Durgella. (Plates LXXVI., LXXVII., LXXVIII., 

 LXXIX.) {Continued from p. 142, Part IV., 1883.) 



I have since been able to examine the other species, D. mairang- 

 ensis, alluded to on p. 145 ; but it becomes necessary in the first 

 place, in order to show clearly the variation between this and other 

 species, to give in this Part drawings and the description of levicula, 

 Benson, the type of Blanford's genus, as well as those oi D. assamica, 

 G.-A. 



Other allied species have in the interval since 1883 been dis- 

 covered, showing that this very interesting group of the Land 

 Mollusca is fairly well represented, though certainly not abundant 

 in species, and that it has a considerable range. 



Early in 1877, Mr. Ossian Limbourg was engaged to collect 

 generally in Tenasserim, the expenses being shared by Lord 

 Tweedale, Dr. John Anderson, and Mr. AVood-Mason, of the Indian 

 Museum, and myself, then in Calcutta. Among the shells he preserved 

 in spirit were a large number of D. levicula, found on the slopes of 

 the Mule-it Eange near a place called Meetan ; a number also 

 reached Calcutta alive, which had been packed in a bamboo-tube, 

 and I was thus enabled to make notes and sketches of the shell- 

 lobes when naturally extended over the shell. I did not then 

 attempt naming the collection until my return to England, and the 

 determination of this species proved somewhat interesting and 

 instructive. Mr. Benson's shells, after his death, passed, through 

 his executors, into the charge of Mr. Sylvanus Hauley, who pub- 

 lished figures of a very large number in the ' Conchologia Indica.' 

 I am sorry to say there was a considerable absence of method in 

 the prosecution of this work ; it is not recorded whether a shell 

 figured was a type shell or from the typical locality ; nor was the 

 shell selected to be drawn labelled as having been so, nor out of 

 whose collection it was selected. Although Mr. Hanley was a 

 keen collector and conchologist, and had worked with Edward 

 Forbes, he was lacking in the sense and appreciation of exact 



