NEW SUBFAMILY AND GENUS ACHATINIDAE 



31 



Achatina (Cochlitoma) graueri 



Pilsbry & Cockerell, 1933:366, pi. 1, fig., 1, la. 

 Callistoplepa graueri 



Bequaert & Clench, 1934c:115. 

 Callistoplepa graueri 



Schouteden, 1935a:110; 1935b:287; Oliver, 1983:9. 

 Callistoplepa babaulti 



Germain, 1936:151, text fig. 46. 



Shell. Shell lacrimoid-subsuccineiform; the thick, durable 

 periostracum appears to provide more support than the thin 

 calcareous shell. Whorls 6-6V2, rarely 7. Spire tapered, 

 mammillate, elevated-conic, clearly shorter than aperture 

 length. The first IV2 whorls form a bluntly obtuse dome. The 

 second and third whorls expand only slightly, but descend 

 rapidly; this produces the strongly mammillate apex. The 

 fourth and following whorls descend proportionately, are 

 increasingly more convex, but expand rapidly to produce an 

 inordinately large last whorl. Sutures moderately deep, 

 increasingly so between fifth and sixth whorls. Last whorl 

 80% of shell length; range for 5-7 whorls, 77-83% (n = 50). 

 Aperture oval to elongate; very thin blue-white shelly layer 

 within. Columella markedly slender, almost entirely concol- 

 orous, slightly arcuate or nearly straight; typically very nar- 

 rowly and obliquely truncate. Outer lip thin, usually 

 somewhat obscured by the more rapidly advancing thick 

 periostracum, which tends to curl into the aperture in dried 

 specimens. The arc of the outer lip is often greatest below 

 midway and basally extended well below the columellar 

 truncation in the more mature specimens. Parietal callus 

 appears to be virtually absent in the smaller specimens and 

 barely visible in the larger and older specimens. 



The first three whorls are unicolorous beige-buff to buff- 

 horn colour. Faint, diffuse wide transverse castaneous bands 

 may emerge in the second whorl and become darker, more 

 conspicuous and fragmented in the third and fourth whorls. 

 These gradually give way to narrow transverse bands of 

 various shades of brown, irregularly appearing coincident or 

 alternating with growth bands. The darkest, broadest bands 

 usually indicate interrupted growth. In some specimens the 

 transverse bands may be essentially absent. Ground colour 

 varies within and between specimens in a spectrum of olive- 

 buff, light yellow-brown, olivaceous brown and medium dark 

 brown. The fifth whorl often has a contrastingly paler ground 

 colour; hence, a 5-whorl specimen, with its short last whorl, 

 may appear to be a different species. 



Pronounced spiral striae, usually 5-7, starting in mid-first 

 whorl are offset by beaded or semilunar granules that are 

 irregular in size and not aligned in vertical rows. The spiral 

 rows of granules increase to 12-17 or more and the now very 

 small granules become more uniform, more prominent, and 

 gradually more transversely aligned in the second and third 

 whorls. At the end of the third whorl, there is a prominent 

 delineation that marks the end of the nepionic whorls. At this 

 point, the granulate sculpture is rather abruptly taken over by 

 thin, slightly prosocline growth wrinkles that increase in size 

 and number until they dominate in the fourth whorl. In the 

 fifth whorl, there is a reemergence of the granulate sculpture 

 in the form of notched, subquadrate, tile-like plates that 

 often resemble the block letters K,H,W,V,Y & M, as is 

 strikingly seen in Achatina reticulata Pfeiffer, 1845. This 

 reappearance of the granulate sculpture, accentuated by the 

 deeper spiral striae, dominates the fifth whorl, although the 

 growth wrinkles continue to increase in calibre and become 



subcrenulate apically. In the usually somewhat darker 

 coloured last whorl, the granulate sculpture is once again 

 greatly reduced, but may be highlighted here and there by an 

 isolated sporadic deep section of a spiral stria. The earliest 

 malleations appear subtly in the third or fourth whorl and 

 intensify in the following whorls. They consist of usually short 

 spiral or diagonal ridges that join or distort the growth 

 wrinkles to form a coarse, irregular raised network of welts. 

 Often entering into this is a very faint elevation at the 

 periphery, below which the otherwise nearly uniform sculp- 

 ture is reduced. An occasional specimen is entirely without 

 malleations. Their irregular appearance is probably explained 

 by thin shell, tough perostracum, and environmental impacts. 

 Continued shell deposition from within 'fixes' the dents in 

 place. Rarely is the outer layer of the thick periostracum 

 broken enough to reveal the shiny inner layer. 



Soft anatomy. Alcohol preserved specimens available 

 82/dissected 9. Zaire: MRAC (Mulungo, no. 204. 632-633) 

 2/2; (Kahusi-Tshibati no. 610.302-305, 342-343) 79/6; ZMB 

 (lectotype) 1/1. Unfortunately, all dissected specimens except 

 the lectotype, were exposed excessively to formalin during 

 their preservation; thus, even with prolonged special treat- 

 ment, their tissues remained hard and the specimens were 

 exceedingly difficult to dissect. Pilsbry and Cockerell (1933) 

 described the living animal as very pale ochreous with head 

 and broad based tentacles faintly bluish. 



Clearly, the most conspicuous and characteristic aspect of 

 the basal genital conduits is the vaginal retentor (VR) muscle 

 system, grossly dominating in ventral view (Fig. 20). Slender, 

 parallel, glistening, partly fused muscle bands pass ventrally 

 from the vagina (V) to the right body wall along a dorsolat- 

 eral line from immediately posterior to the genital aperture to 

 the junction of the mantle and the right body wall. From the 

 left side of the vagina, this system gives rise to a series of 

 muscle bands that starts at the peniovaginal angle and binds 

 tightly together the equally prominent apical vas deferens 

 (AVD) and the free oviduct (FO). A more bold series of 

 distinct, but laterally fused muscle bands pass from the left 

 lateral aspect of the AVD to the same right dorsolateral line 

 of attachment, further obscuring the basal genital structures. 

 (These bands are shown cut short in this figure.) Apically this 

 whole muscle system is reduced largely to a thin, transparent 

 membrane attached to the junction of the AVD and the FO. 

 At this same junction, a similar membrane passes to the 

 spermatheca (S) and attaches it to the FO. The S is propor- 

 tionately extremely large in this species. In four of the nine 

 specimens examined, the slender apex of the S is folded back 

 on itself, as shown here; this is apparently a common artifact 

 of preservation. In the rest, the apex is extended, and 

 although it may appear to go apically beyond the junction of 

 the AVD and FO, it is not attached to the spermoviduct (SO) 

 as it is in many achatinids. The spermathecal duct (SD) is so 

 short and broad that when the S is gorged, it seems to be 

 sessile on the V. 



Short, often diagonal or anastomosing muscle bands, sepa- 

 rate or combined, are found at the base of the penis sheath 

 (PS) and the V. These eversion muscle bands (EM) initiate 

 the precopulatory extroversion of the genital atrium (GA). 

 The PS normally completely envelops the short, diminutive 

 penis (P); in only one of nine specimens, the apical P 

 projected slightly. The penial retractor (PR) has its origin on 

 the apical P and inserts on the mid-forward diaphragm at or 

 near the junction with the body wall. A single specimen, 



