272 ekidjE. 



The straight, acute margins of the peristome, gWing the shell 

 an Achatinoid aspect, so difiereut from typical Ena, are a 

 character sufficient, iu my opinion, to warrant the retention of 

 the o-roup as a separate genus, and I therefore follow Bour- 

 guignat's lead in this respect. 



The radula closely approximates that of Ena ohscura, according 

 to Scliacko *. A specimen of B. punctatus from Tette is reported 

 on by him as follows : — Central tricuspid, very small ; laterals, 

 stronf , with a large, obliquely truncate central plate ; marginals 

 very abundant, with 7 side cusps. 



This genus, establislied in 1889 by Bourguignat, had been uni- 

 versally relegated to the synonymy of EacMs, Albers {EJiachis, 

 Pfeiiie'r and von Martens), but recently Dr. Thiele t has stated 

 that an examination of the radula of punctatus has satisfied him 

 that this species does not pertain to the latter genus but to Ena 

 in its wider sense. He consec^uently revives Bachisellus but 

 reduces it to a subgenus of Ena. Although von Martens indi- 

 cated punctatus as the type of the former, at the same time, 

 following in Pfeiffer's footsteps, altering its orthography to 

 Rhachis, Dr. Thiele points out that as this species was not in- 

 cluded by Albers in 1850 when the section Rachis was established 

 by him, with Bulimus pallens, Jonas, as first species, the latter 

 must be regarded as type. 



241. Rachisellus adumbratus, Pfeiffer. 



Bulimus adumbratus, Pfeiffer, P. Z. S. 1854, p. 291; ibid., Mon. 



Ilelic. Viv. iv, 1859, p. 472; Plauley & Theobald, Conch. Ind. 



1876, pi. 148, fig. 8. 

 Bidhnus {Rhachis) adumbratus, Pfeiffer, Malak. Blatt. ii, 1856, 



p. 161. 

 Bidiminus (Rhachis) adumbratus, von Martens, Die Heliceen, ed. 2, 



i860, p. 231 : Nevill, Hand List, i, 1878, p. 130 ; Kobelt, Conch.- 



Cab., Fara. Buliniinidae, 1900, p. 675, pi. 102, fig. 19. 

 Bulimus adumbratus, Nevill, Enum. Ilelic. Cevlon, 1871, p. 3. 

 BuUmina (Rachis) adumbrata, Pfeiffer & Clessin, Nomeucl. Helic. 



Viv. 1881, p. 285. 

 Rachis adumhratus, Jousseaume, Mem. Soc. Zool. France, vii, 1894, 



p. 296. 

 Rhachis adumbratus, Kobelt & MollendorfF, Nachr. Deuts. Malak. 



Ges. 1903, p. 37. 



Oriqinal description : — " T. subobtecte perforata, ovato-conica, 

 solidula, laevigata, albido et roseo adumbrata, strigis distantibus 

 roseo-fuseis et punctis sparsis pellucidis signata ; spira conica, 

 apice acuta, nigra; anfr. 6 vix convexiusculi, ultimus spira paullo 

 brevior, basi rotundatus, fascia 1 castanea notatus ; columella 

 subverticalis ; apertura obhqua, oblongo-ovalis ; perist. simplex, 



* In Mobius, Beitr. Meeresfauna Ins. Mauritius u. Seychellen, 1880, p. 340. 

 t Wiss. Ergebn. Deuts. Zentr.-Afr. Exp. iii, Zool. 1911, p. 201. 



