NEW SUBFAMILY AND GENUS ACHATINIDAE 



25 



Type locality. Forest of Piani Kapuri, Maniema 

 (=Manyema), Zaire 3° 34' S, 26° 53' E. 



Distribution. Next to B. pintoi, this is the most wide 

 spread species in the genus (Fig. 16). The known specific 

 localities delineate essentially the southeastern quarter of 

 Zaire, with Nsendwe, near Kindu-Port-Empain, Maniema 

 region in the northwest; Uvira, Kivu region in the northeast; 

 Mpala, Tanganyika region in the east; Lake Mwero 

 ( = Moero), Kantanga region in the southeast; and Dilolo, 

 Lualaba region in the southwest. The only records outside 

 Zaire are (1) in Abercorn (= Mbala) at the southern tip of 

 Lake Tanganyika, Zambia, and (2) on the Tanzanian east 

 shores of this lake, based on Germain's synonym Serpaea foai 

 (1905, 1908). Meredith (1983b) and N. Gray (correspon- 

 dence) failed to find it during extensive collecting in Malawi. 

 The largest and finest specimens extant were collected in the 

 Lake Mwero region (BMNH) and Kamina (MRAC). 



Remarks. This plesiomorphic wide spread species is most 

 closely related to B. marteli. Specimens have been found in 

 mixed lots along with B. marteli and Achatina craveni. The 

 juvenile specimens of all three species are easily confused. 

 Further, the full grown specimens are quite variable in shape, 

 colour, sculpture and pattern, with the not uncommon atypi- 

 cal forms of each species contributing to the difficulty of 

 identification. The young specimen that Grauer collected in 

 the virgin forest 50 km east of Kasongo, Zaire, and identified 

 as Achatina fulminatrix von Martens, 1895 by Thiele 

 (1911:205) was examined in Berlin (ZMB) and found to be B. 

 pellucida. Extensive series of this species are in Bruxelles 

 (IRSN) and Tervuren (MRAC). 



tit quae it in a marteli (Dautzenberg, 1901) 

 Figs. 37-40 



Achatina marteli 



Dautzenberg, 1901:3. 

 Ganomidos marteli 



Dautzenberg, 1901, pi. 1, fig. 1. 

 Achatina marteli pallescens 



Dautzenberg, 1901:3. 

 Ganomidos marteli pallescens 



Dautzenberg, 1901, pi. 1, fig. 2. 

 Callistoplepa marteli 



Pilsbry, 1905:129, pi. 47, fig. 21 (ex Dautzenberg); Ger- 

 main, 1909:90; Pilsbry, 1919:81; Bequaert & Clench, 



1934c:114. 

 Callistoplepa marteli var. pallescens 



Pilsbry, 1905:129, pi. 47, fig. 22 (ex Dautzenberg); 



Bequaert & Clench, 1934c: 114. 

 'Achatina sp. near tavaresiana 



Verdcourt, 1966:106, fig. 12; 1988:219. 

 Callistopepla marteli 



Germain, 1936:151; Oliver, 1983:9. 



Shell. Shell ovate-achatiniform, opaque, thin but not frag- 

 ile. Whorls 6-6V4, rarely 6V2. Spire moderately broad, conic; 

 apex obtuse; only one out of 69 specimens examined had a 

 mammillate apex. Upper whorls only slightly convex, 

 descending proportionately but expanding somewhat more 

 rapidly. Sutures fine and regular in nepionic whorls, shallow 

 to moderately deep and irregular in the following whorls. 

 Last whorl large and more convex, 80% of shell length; range 

 for 4V2-6V2 whorls, 77-84% (n = 69). Aperture inverted 



auriform to ovate-elongate; pale blue-white within; surface 

 pattern and flames show through. Columella straight or 

 weakly arcuate, somewhat slender, concolorous but with a 

 thin calcareous film; usually moderately obliquely truncated. 

 Outer lip thin, extending basally only a slight way below the 

 truncation; its arc is characteristically greatest below midway 

 in the mature specimens. Parietal callus thin but apparent 

 even in the smaller specimens. 



The nepionic whorls (first 2V2) are unicolorous pale buff- 

 white. This changes imperceptibly to a uniform dull ground 

 colour that varies in specimens from a rather intense oliva- 

 ceous yellow to subdued olivaceous. In most specimens, 

 faint, very diffuse light castaneous blotches appear in the 

 fourth whorl. At first these are vertical, evenly spaced and 

 broader at their base; but they soon become fragmented 

 apically, darker, and strikingly distorted into diagonal even 

 spiral, irregular streaks, bands and flames that are approxi- 

 mately as wide as the ground colour space between them. In 

 the present study of 69 specimens, 72% are flammate, 13% 

 are vaguely flammate but only on the last whorl, and 15% are 

 without flames, i.e. 'pallescent'. In some of the latter, e.g. the 

 lectotype of Achatina marteli pallescens, lines of arrested 

 growth are highlighted with thin bands of dark brown. 



A delicate beaded or slightly semilunar sculpture starts in 

 the second quarter of the first whorl and quickly assumes in 

 the early second whorl the diagnostic sculpture of strikingly 

 coarse, elevated, round or crescentic, discreet but tightly 

 packed beads that are neatly aligned in 5-7 spiral rows. This 

 pattern persists almost uniformly throughout the second 

 whorl. In the mid-third whorl, the transverse rows become 

 greatly compressed, producing growth wrinkles and convert- 

 ing the beads into transverse welts 2-3 times as long as wide. 

 This doubtless marks the first postemergent growth. Adaper- 

 tural to this, the growth wrinkles become prosocline, the 

 sculpture gradually becomes less compressed, the spiral striae 

 become more numerous and deeper, and the individual welts 

 become larger, more variable in size, more rectangular, and 

 often cleft. The remarkably evenly and closely spaced coarse 

 growth wrinkles embrace and intensify the prosocline rows of 

 welts, producing the characteristic prominent ribbed sculp- 

 ture of this species. Apically, the ribs may bifurcate and form 

 crenulations. Below the periphery, the welts rather abruptly 

 reduce to one-quarter their calibre, or are absent, leaving 

 prominently the growth wrinkles. An extremely fine decus- 

 sate micromesh of the periostracum appears on the last whorl 

 of some specimens. It is more noticeable on the shiny inner 

 layer of the periostracum where the latter is exposed through 

 wear or injury. It is apparent that the micromesh is formed at 

 the time that the inner periostracal layer is laid down and that 

 it is largely obscured by the preformed, smoother outer 

 periostracal layer. It is likely that the micromesh assists 

 structurally in bonding the two periostracal layers. 



Soft anatomy. No known alcohol preserved specimens. 



Type material. In his description of this species and its 

 synonymous unicolorous 'variety pallescens\ Dautzenberg 

 (1901) announced that he was dedicating them to Colonel 

 Martel and that specimens had been collected by R.P. 

 Guilleme 'en nombreux exemplaires' in the region of Lake 

 Tanganyika. He did not specifically designate types and 

 paratypes, although he selected a fine flamed specimen and 

 an equally fine unicolorous specimen that were photo- 

 graphed, both in apertural view only, as representative of the 



