A.R. MEAD 



thin on the surface of the P and so intricately associated with 

 it, as to be essentially imperceptible. About midway on the P, 

 the PS suddenly goes from thick to thin. This creates a 

 transverse line of thin folds that incorrectly suggests the PS 

 terminates at that level (Mead, 1992, fig. 2). However, when 

 there is extreme contraction during preservation, the apical 

 edge of the PS actually does pass basally far enough to allow 

 the apical structures to elbow out of the PS (Fig. 3). The 

 contraction emphasizes the bipartite nature of the P: an 

 apical convoluted, transparently ensheathed portion and a 

 basal irregularly bulging, opaquely ensheathed portion that 

 contains the pilaster (PIL). Internally, the most basal P is 

 longitudinally plicate; above that, including the PIL, the 

 epithelium is vermiculate-rugate. The PIL is a simple, greatly 

 thickened, longitudinal, roundly elevated ridge of the ventral 

 penial wall that strongly projects dorsally into the lumen of 

 the P. Basally, this ridge terminates into a solid, inverted- 

 conical, pendulous verge-like process. Although its margins 

 are not well defined, axially the PIL has a more gross 

 epithelial texture than the surrounding tissue. The apical vas 

 deferens (AVD) is a conspicuously uniformly slender conduit 

 (—1.0 mm in width). It lacks the heavy muscular basal 

 portion found in C. shuttleworthi, thus the physical support 

 for the intromittent organ in C. barriana doubtless is pro- 

 vided by the thick, longitudinal P. 



The vagina (V) is a short, nearly uniformly wide conduit, 

 about one-third the length of the P. Internally, it is lined with 

 vermiculate-rugate epithelium and is without any apparent 

 modifications at its junction with the spermathecal duct (SD) 

 and free oviduct (FO). The muscular FO is as wide or wider 

 than the V, 2-3 times as wide as the SD, and about as long as 

 the SD. For their full length, both FO and SD are tightly 

 bound to each other by fairly regularly appearing small slips 

 of muscle. The junctions of the AVD/FO and spermatheca 

 (S)/SD are pulled in close juxtaposition by the tissues of the 

 sagittal myoseptum. Just apical to this, the capitate S, about 

 the length of the V, is broadly attached to the basal (uterine) 

 portion of the spermoviduct. The SD is a thin-walled mostly 

 uniformly slender conduit about the caliber of the AVD. Five 

 gravid specimens were examined; three with full data had 

 been collected near the end of the rainy season in October/ 

 November. For such a relatively small species, the eggs are 

 quite large (6.8 x 5.4-6.3 x 5.1 mm). Fully gravid specimens 

 contained 11-15 eggs, all with heavy, calcareous shells and 

 distributed in the full length of the spermoviduct. The ovotes- 

 tis acini appear in four or five discrete clusters under the 

 columellar surface of the right (apical) lobe of the digestive 

 gland. A talon with a round base and an apical, diverticulate 

 elongation is present. 



The genital atrium (GA) in this species is unique among 

 the achatinids so far dissected. It is comparatively large and 

 so shallow that it is essentially a common genital depression, 

 immediately within which appear conspicuously the male and 

 female orifices. These latter, like twin craters, are individu- 

 ally surrounded by low elevated circular walls of smooth 

 tissue, which contiguously fuse at their inner margines (Fig. 

 3). 



Type material. Sowerby (1890:579) did not designate a 

 holotype. The BMNH specimen '89:11.19.2 purchased of 

 Sowerby' is here designated the lectotype (Figs. 23, 24; Table 

 1). The slightly damaged and trimmed second syntype, 

 NMW, 1955:158.832 in the Melvill-Tomlin collection is here 

 designated a paralectotype (Oliver, 1983). Remeasurements 



of the lectotype confirm Sowerby's figures except for the shell 

 length, which is 41.0 mm rather than '43 mm'. Sowerby's 

 illustration is so poorly rendered that it is not precisely 

 identifiable with either syntype. 



Type locality. 'Calabar, Africa?' Nigeria, 4° 57' N, 8° 19' 

 E. J.C. Reid of the University of Calabar recently confirmed 

 this queried locality. Although he has made many excursions 

 into the 'relatively undisturbed Oban Hills Forest which 

 yields a rich fauna', he found only two (live) specimens along 

 a permanent stream at Aking (= Awsawmba) 5° 26' N, 8° 38' 

 E, 78 km northeast of Calabar. One of these specimens 

 (BMNH) was examined anatomically and conchologically in 

 the present study and was found to be typical; the second 

 specimen is reportedly in the Tom Pain collection (NMW). 



Distribution. This species has been found essentially along 

 the entire expanse of coastal Cameroon from M'Bonge (= 

 Bonge) 4° 33' N, 9° 05' E in the north to Itoki 2° 24' N, 9° 50' 

 E in the south. Most of the known twenty localities are 

 clustered in northwestern Cameroon, spilling over into south- 

 eastern Nigeria and extending inland as far as Yaounde 3° 52' 

 N, ll°31 o E;Metet3°05'N, 11° 00' E; Ebolowa2° 54' N, 11° 

 09' E and Sangmelima 2° 56' N, 11° 59' E. The nine other 

 localities are in the environs of Victoria 4° N, 9° E. In all 

 localities, seven were shared with C. shuttleworthi and five 

 were shared with Leptocala mollicella. Only a single general 

 locality record was found for Gabon (Verreaux, 1855 

 NHMB) and no record for Equatorial Guinea; but this 

 species eventually probably will be found to be limited to the 

 northern regions of these two countries. Data labels indicate 

 that specimens were collected in plantations in Kumba 4° 38' 

 N, 9° 25' E (bananas), Missellele 4° 07' N, 9° 25' E (coca), 

 'Buenga' (oil palm), and in primary forests. 



Table 1 



C. barriana - 



Representative shells measurements. 







Greatest Aperture 



Last 



/o 







Whorls 



Length 



Width 



Leng 



h Width whorl LW/L % 



W/L 



6V4 



59.0 



32.4 



36.1 



19.5 



49.0 



82 



55 



Bonge 



(UUZM) 



6V< 



57.5 



30.0 



32.8 



16.9 



46.0 



80 



52 



Victoria 

 (ZMB) 



6 



50.7 



27.8 



30.9 



16.8 



41.9 



83 



55 



Idenau 

 (SMF) + 



6 



49.0 



29.9 



30.6 



17.5 



40.8 



83 



61 



Bonge 

 (SMNH) 



5% 



44.0 



27.4 



29.6 



16.3 



37.8 



86 



62 



Bonge 

 (SMNH) 



6 



41.0 



23.3 



24.9 



14.5 



32.3 



79 



57 



Calabar 

 (BMNH) 

 LectA. 

 barriana* 



6 



41.0 



22.8 



26.6 



13.4 



34.0 



83 



56 



Kumba 

 (MRAC) 



795.173 



5V2 



36.8 



23.0 



23.6 



13.4 



29.8 



81 



62 



Idenau 

 (SMF) 



5 



25.2 



15.3 



16.4 



8.8 



20.6 



82 



61 



Bibundi 

 (SMF) 



4% 



20.5 



13.8 



13.2 



7.6 



16.8 



82 



67 



Bibundi 



(SMF) 



Total specimens examined: 125. Sources: BMNH, CMNH, IRSN, MCZ. 

 MNHN, MRAC, NHMB, NHMW, NMW, SMF, SMNH, UHZL UUZN, 

 ZMB, ZSM. 



