OCR Text |
Show 476 MR. G. F. ANGAS O N T H E [June 3, the apex, which is somewhat obtuse; base very slightly convex; aperture very oblique, subquadrate ; outer lip expanded and sinuous above, with a produced horizontal beak at the periphery, arcuate and somewhat reflexed below. Diam. maj. 13|, min. 10, alt. 10 lin. Hab. Along the Zhorquin river, Costa Rica. " Animal very slender, nearly white, pale brownish on head and top of body" (Gabb). Five adult and three young specimens found, all of the same coloration. This very remarkable and elegant shell is the gem of the collection. It belongs apparently to the same section as H. bifasciata from Brazil. 2. HELIX .ESOPUS, Angas, P. Z.S. 1878, p. 72, pi. 5. figs. 11, 12. Some of the specimens show a dark band round the umbilical region, and are larger than the type specimen figured in the Zoological Society's 'Proceedings,' whilst one of them shows traces of concentric lines, especially towards the front of the last whorl. The nearest ally to this species is H. triplicata, Martens, which, however, is smaller, and differs in the shape of the peritreme. " The animal is grey above, with the foot nearly white" (Gabb). Found in the coast region and to the hills of Uren, at an altitude of 3000 feet. The type specimen was found at Buena Vista at a similar altitude. Seventeen specimens found, five only unbleached. 3. HELIX MAC-NEILI, Crosse, Journal de Conch, vol. xxi. p. 67. Of this small species only three fresh specimens and a few dead ones were found. " Animal dark brown ; tail and foot slightly lighter ; upper tentacles long" (Gabb). Coast region and lower hills, from Parismina to the hills of Zhorquin. 4. HELIX COSTARICENSIS, Roth ; Pfr. Mon. Hel. iv. p. 302; Pfr. Novitat. i. 21. 15-17- This is an extremely variable species, both in colour and form as well as in size; still I cannot detect in the series before me any differences that would amount to specific characters. The base is invariably white, with a dark-brown umbilicus, and the umbilical region tinged with bright yellow. The three principal varieties appear to he :-1st, large, depressed, white, with two or three narrow dark-brown bands; 2nd, small, depressed, with the upper surface light or dark brown throughout, or zoned with both colours; 3rd, medium in size, much more conical, with two broad bands of light brown, or all light brown above. This last variety was described by me in this Society's 'Proceedings' for 1878, under the name of Helix boucardi, from specimens brought home by Mons. Boucard from the region |