294 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



near Honolulu (2,000 feet), and some collected between Olaato Kilauea 

 (2,000 to 4,000 feet), exhibit numerous minute variations in tlie form 

 and position of the generative organs, which tend to make identification 

 a very difficult matter. Some of these variations I have figured 

 (Figs. 2, 3, and 8), and in all probability there are many more. 



In dealing with these small specimens of Amalia and Agriolimax, 

 I have been much imjiressed with the little value that can be 

 attached to external features, especially in these two particular genera. 

 Anyone examining the material I have had, and relying upon purely 

 external features, will be able to endow the Sandwich Isles with 

 numerous new '' species" of both Amalia and Agriolimax, since forms 

 in which the generative organs are almost identical exhibit differences 

 in the colour, markings, length and breadth of the mantle, nature of 

 the sulci, and form of the rugce, to such an extent that any diagnosis 

 based solely on these features would be worthless. So closely allied 

 are many species of these two genera, while others are connected by 

 intermediate forms or subspecies, that I have come to the conclusion 

 that in addition to descriptions and figures of the generative organs, 

 which are sufiicient for si)ecific determination in most genera, it is very 

 desirable that some other organs should be figured and described — the 

 alimentary or nervous systems, I would suggest — in addition to the 

 form, origin, and insertion of the buccal, penial, and tentacular retractor 

 muscles. These, and all other features, would be of much greater 

 value if described from freshly-killed auimals ; for the specialist, who 

 very often is compelled to examine only material which has for many 

 months been in alcohol, works at considerable disadvantage, especially 

 in the case of these minute forms. 



1. Amalia Baboei, n.sp. 



Animal. — Anterior portion of head, mantle and dorsum, dark sepia, 

 sides of body nearly as dark posteriorly, much lighter anteriorly, also 

 in the region bordering the front and sides of the mantle ; portion 

 beneath the mantle yellowish-brown ; mantle (Fig. 5) longer than broad, 

 with distinct groove ; foot-fringe yellowish-brown, darker posteriorly ; 

 foot-sole yellowish-brown, with median and lateral planes sharply 

 marked. Ruga3 large. Keel prominent. Length (in alcohol) 20 mm. 



Shell very fragile, consisting of a series of small calcareous jiarticles 

 indefinitely arranged, the general form being as shown in Fig. 6. 

 Length 3, breadth 2 mm. 



i/rt^.— Haleakala, Maui, 5,000 feet, and Olaa to Kilauea, 2,000 to 

 4,000 feet (one specimen). 



Anatomy. — The free-oviduct is a short tube, from one side of which 

 there is a small oval-shaped diverticulum. The penis commences as 

 a thin tube, expanding into a globose sac, beyond which it exhibits 

 a number of constrictions, and terminates abruptly, giving place to 

 the vas deferens, which passes off as a short fine tube. There is 

 a large bilobed accessory gland (Fig. 4, ac.gl.) attached to the com- 

 mencement of the free-oviduct by seven fine ducts, immediately above 

 which the ])yrifonu reccptacidura seuiinis oj)ens ; its duct is short. 



