CORILLA. 53 



Subfamily COBILLIN^E. 



Genus CORILLA, Adams. 



Cot-Ma, Adams, -Gen. Rec. Moll, ii, 1855, p. 208; Semper, Keisen 

 Arch. Philippine!!, Wiss. Res. 2, iii, 1870, p. 100 (anatomy) ; 

 Pilsbry, Man. Conch., ser. 2, ix, 189-1, p. 147 (anatomy) ; Gude, 

 Science Gossip, N. s. iii, 1896, pp. 88, 126 (armature) ; Pilsbry, 

 Proc. Mai. Soc. London, vi, 1905, p. 288 (anatomy) ; Godwin - 

 Austen, Moll. India, ii, 1907, p. 199 (anatomy). 



Atopa, Albers, Die Heliceen, 1850, p. 90 (in part). 



" Shell planorboid, with nearly plane spire and broadly open 

 umbilicus, the contour subcircular or oblong ; rather solid, striated 

 above, brown or yellow. Whorls 5-5|, the last deflected in front. 

 Aperture oblique, the lip broadly reflexed or recurved, its ends 

 distant ; parietal wall smooth or armed with a strong entering 

 lamella. Interior of the last whorl either without laminae or 

 obstructed by a series of Hades nearly parallel to the direction of 

 the whorls, but having no transverse barriers. 



*' Foot (of C. erronea) with undivided sole and without pedal 

 grooves. No mantle lappets. Kidney very short. 



" Jaw entirely smooth. Radula with about 79-85 teeth in a 

 transverse row. Central tooth not smaller than the laterals, 

 having a single cusp, shorter than the basal plate. Lateral? 

 similar but asymmetrical. Marginals having a large, simple, 

 oblique cusp longer than the square basal plate. 



" Genital system elongated, with no accessory organs on the 

 female side. Spermatheca having a long duct, which branches 

 into a very long flagellum-like diverticulum, containing a cylindrical 

 spermatophore, which extended from the end of the diverticulum 

 to the vagina. Penis short, swollen distally, continued in the 

 vas deferens upon which the penis retractor is situated, the distal 

 end of the retractor being inserted on the uterus. This species 

 [(7. erronea'] is ovoviviparous, the uterus in the individual figured 

 containing two young, having a membranous shell of about 

 5 mill, diam., and more than 3 whorls. 



"The shell differs from that of Plectopylis in lacking internal 

 barriers transversely obstructing the passage. When internal 

 lamellae are present in Gorilla they run parallel to the sutures or 

 nearly so, as in Polygyratia. The central teeth are not smaller 

 than the laterals as in Plectopylis, and there are further differences 

 in the genitalia." (Pilsbry.} 



TIPE, Helix erronea, Albers. 



Range. Ceylon ; Southern India (1 species). 



When examining the soft parts of Gorilla humberti in 1905, Prof. 

 Pilsbry found that the additional data obtained threw no light upon 

 the affinities of the groups with other Helicidse. He further states 

 that the suspicion he formerly entertained that Gorilla might be 

 related to the Macroogona is negatived by the knowledge we now 



