246 MKS. JANE LONGSTAFF ON NON-MARINE 



Now a slender form has been described by Sliuttleworth * under the name 

 of candidhsima, and it is represented as pure white in the figures, though he 

 states there are traces of straw-yellow streaks on the last whorl, and that the 

 epidermis is thin, pale, and horny. He had only one example, which was 

 from Kordofan. 



V^oii Martens t refers to the traces of brown streaks on this specimen, 

 though at first sight it appears white^ and he regards these streaks as similar 

 to those on L. raiUiaudi, Pfeiff. (L. fiammata). Jickeli J also states that, 

 though he has figured a unicolorous example, he has specimens before him 

 with stripes more or less the same as those on L. sennaariensis, Shutt. 

 {flammata) . 



Von Martens § has described and figured a small shell from the Bahr el- 

 Ghazal resembling L. candidissima in shape, but smaller and having very 

 decided brown streaks, as variety gracilis. 



Still another elongated shell has been described by Dr. Pilsbry || from the 

 Omo River, similar to the last in form and colour, but more elongated ; it is 

 named var. smitJii. 



The streaks or flammules with which the shells of this group are orna- 

 mented vary in width, distance apart, and also in depth of colour, which may 

 be light yellowish-brown, dark brown, or almost black. Owing to the habit 

 that molluscs have of burying themselves in the earth, it is common to find 

 shells, both stout and slender, bleached on one side, while more or less of the 

 epidermis and flammules may be preserved on the other. 



It is most unfortunate that a name of the significance of candidissima 

 should have been given to a holotype ; also it is unfortunate that the repre- 

 sentative of the var, gracilis should have been a small form. Since Jickeli 

 and M. Pallary both comprise the slender shells agreeing in shape, whether 

 striped or unicolorous, under the varietal name of candidissima, I think it 

 advisable to follow their example. 



In my collection the groups found at different localities, besides varying 

 among themselves in the width of the spiral angle, have also each a dis- 

 tinctive facies, showing slight differences in form and colour according to 

 their respective habitats. 



In consequence of this fact, I consider it most convenient to record the 

 specimens topographically, when I shall reserve the word holotf/pe to signify 

 L.jiamniata, sensu stricto. 



It would of course be possible to make a number of sub-varieties based on 

 slight peculiarities, but these would be of no value without a knowledge of 



* ' Notit. Malac' vol. i. 1856, p. 49, pi. 6. figs. 7, 8. 



t Malak. Bliitt. 1865, p. 197. 



% 'Fauna Land- ii. Siisswasser-Moll. N.O.-Afrikas/ p. 161. 



§ Malak. Blatt. vol. xvii. 1870, p. 34. 



It ' Man. Concli.' vol. xvi. 1904, p. 28.3, pi. 22. figs. 37, 38. 



