30 



unicolorous nepionic whorls to an obscuring dark olive brown 

 of the last whorl. 



Faint, closely oppressed minute crescentic granulations 

 may appear in the second half of the otherwise smooth first 

 whorl. These granulations dominate the second whorl, giving 

 it an evenly, delicately engraved appearance. In contrast, 

 rather bold, diagonally oriented arcuate plicae, arising from 

 the suture below, disrupt this sculpture in a narrow basal 

 zone. This plication, which may start even in the last part of 

 the first whorl, rather abruptly disappears in the third whorl, 

 leaving a delicate, closely aligned series of nearly transverse 

 lirae, uninterrupted except for small, sparce, ghost-like 

 patches of granulations in some specimens. This marks the 

 end of the nepionic whorls. In the fourth and fifth whorls, the 

 lirae become increasingly strongly prosocline, more regular, 

 apically arcuate immediately below the suture, and eventu- 

 ally so prominent that they obscure the growth lines. In the 

 sixth whorl, the lirae become finer, less regular, more nearly 

 orthocline, and often interspersed with short parallel lirellae. 

 In the fifth whorl, spiral lirae, which seem to join rather than 

 interrupt the prosocline lirae, appear somewhat irregularly, 

 producing a slight checkerboard effect, reminiscent of the 

 sculpture of Achatina tracheia Connolly, 1929. These spiral 

 lirae, which are quite close together near the suture, irregu- 

 larly diminish in number and intensity toward the columella. 

 Very shallow malleations, starting subtly in the fourth whorl, 

 intensify the checkerboard effect. A subdued but apparent 

 carina appears at the periphery, where the lirae are seen to 

 bend slightly. The carina is more conspicuous in the younger 

 specimens. Abrasion of the shell along the periphery and 

 along some of the more prominent lirae visually intensifies 

 the carina and the sculpture by exposing the brilliantly shiny 

 inner periostracal layer. The outer layer of the periostracum 

 imparts a characteristically dull, corneous luster to the shell. 



Soft anatomy. No known alcohol preserved specimens. 



Type material. Nine of the ten known specimens of this 

 rare species were collected by Dupuis and are considered 

 syntypes. Six of these were identified and labelled as 

 'cotypes': three in Tervuren (MRAC no. 5140-5142) and 

 three unnumbered specimens in Bruxelles (IRSN, General 

 Collection). The seventh specimen (MRAC no. 5139) was 

 labelled as the one figured by Dupuis & Putzeys (1900); their 

 figure 18 (reproduced by Pilsbry, 1905) is so generalized that 

 it cannot specifically identify with any of the syntypes. 

 Unfortunately, the apex of this specimen had been broken 

 and cemented together, with a resultant alteration of the shell 

 configuration and length. The damage possibly occurred 

 during the precarious period when the artist had the speci- 

 men. Two additional syntype specimens (IRSN) were given 

 to Dauzenberg by Dupuis, one of which was collected in 

 Nsendwe. Under these circumstances, and since the authors 

 did not designate a holotype, the largest and finest of the four 

 MRAC syntypes (no. 5140) is here selected as the lectotype of 

 Dupuis & Putzeys' Ganomidos fraterculus (Figs. 52, 53; 

 Table 9). The tenth known specimen, acquired by Preston, 

 was passed on to V.W. MacAndrew, and is now in the 

 BMNH. Its apex was damaged and repaired naturally. This, 

 too, most probably was collected by Dupuis and should be 

 considered a paralectotype. 



Type locality. The Island of Mvula on the Lualaba 

 River, Zaire. J.C. Bequaert was unable to find this locality 

 on any map (Pilsbry, 1919:11, 19), nor is it listed in the 



A.R. MEAD 

 Table 9 B. fraterculus - Representative shells measurements. 



Whorls 



Length 



Greates 

 Width 



t Aperture Last % 

 Length Width whorl LW/L 



. % 



W/L 



6 



51.0 



28.7 



30.0 



16.4 



40.7 80 



56 



Mvula 



(BMNH) 



PLec 



6 



50.5 



29.0 



30.0 



16.9 



39.3 78 



57 



Mvula 



(IRSN) 



PLec 



6V4 



50.4 



28.5 



30.5 



17.0 



38.9 77 



56 



Mvula 

 (MRAC) 

 5140 Lect* 



6 



47.5 



27.4 



27.8 



16.0 



37.5 79 



58 



Mvula 



(MRAC) 



5139 



6 



46.3 



26.8 



28.7 



15.5 



36.7 79 



58 



Mvula 

 (MRAC) 

 5141 PLec 



6 



44.4 



26.6 



27.2 



14.8 



35.0 79 



60 



Nsendwe 



(IRSN) 



PLec 



6 



44.3 



26.4 



26.7 



14.5 



34.0 77 



59 



Mvula 



(IRSN) 



PLec 



5% 



40.2 



26.4 



26.2 



14.2 



32.6 81 



66 



Mvula 

 (MRAC) 

 5142 PLec 



5% 



37.5 



23.0 



22.6 



13.2 



29.7 79 



61 



Mvula 



(IRSN) 



PLec 



5% 



36.5 



21.7 



22.0 



12.2 



28.2 77 



59 



Mvula 



(IRSN) 



PLec 



Total specimens examined: 10. Sources: BMNH. IRSN. MRAC. 



current USBGN series. The only lead is the fact that a 

 single specimen of this species in the Dautzenberg collec- 

 tion (IRSN) bears the data: 'Nsendwe, Congo. P. Dupuis 

 Coll., leg & ded\ At the same time that Dupuis & Putzeys 

 described Ganomidos fraterculus (1900), they described 

 the new species Perideriopsis mvulaensis, giving its locality 

 as 'ile de Mvula (en face de Nsendwe)'. Bequaert in Pilsbry 

 lists Nsendwe as 3° 05' S, 26° E. This location nearly 

 coincides with the important crossroad Kindu-Port-Empain 

 2° 57' S, 25° 56' E, hence Mvula must be very close to 3° S, 

 26° E. 



Distribution. The two known localities for this species are 

 the Island of Mvula and the nearby onshore village of 

 Nsendwe in Zaire. Given the nature of the riverine environ- 

 ment, this species may well be found on other of the many 

 small islands and possibly in shore sites along this northward 

 flowing remote section of the Lualaba. 



Remarks. Phylogenetically, this species appears to stand 

 between B. graueri and the plesiomorphic B. pellucida. 

 Based on a single specimen from Nsendwe (BMNH, Preston 

 'L/K 13/11/01'), B. pellucida may be sympatric with B. 

 fraterculus. 



Bequaertina graueri (Thiele, 1911) 

 Figs. 54-57 



Achatina graueri 



Thiele, 1911:205, pi. 5, fig. 43; Pilsbry, 1919:78. 



