1 40 PTEROrODA'. 



2. CuMiNGii, f. 4, Deshayes. — Qaam H. tridenfata ma^is 

 obloiiga, rostro suhtrigono magis producto, appendicibus 

 paulo magis approximatis. — Rather narrower in proportion to 

 length, rostrum more produced and trigonal, and appendages 

 more approximate than in H. trldentata. 



3. FLAVA, f. 3, Orhigny. — Flava, quam //. tridentaia 

 magis angusta, appendicibus acutis, approximatis, lateribus 

 supra appendices contractis. — A yellow shell, thinner and 

 more contracted at the sides than sp. 1. 



4. AFFiNis, f. 10, Orhigny. — Quam H. tridentata angustior 

 at magis tumida; rostro, apice et appendicibus magis pro- 

 diictis. — The body part of the shell is much smaller in 

 proportion to the rostrum, apex and appendages, which are 

 much more produced than in sp. 1. 



5. UNCINATA, f. 7, 8, Orhigny. — Dense fusca, ventri- 

 cosissima, versus aperturam paulo angustata ; apertura 

 angusta, rostro elevato appendicibus lateralibus magnis, apice 

 uncinato. — A dark brown shell, with the aperture narrow and 

 the rostrum turned upwards. Most remarkable for backward 

 curve of the apex. 



6. GIBBOSA, f. 1, 2, Hang. — Elongato-subovata, alba altis- 

 sime gibbosa ; disco superiori oblique conico, medio angulato, 

 ante angulum rugato ; rostro producto, acclivi, bilobato; 

 appendicibus acutis, approximatis apice deflexo. — The central 

 gibbosity is raised into an angle, with wrinkles on the front 

 slope, and the apical spine is bent downwards. 



7. GLOBULOSA, f. 8, 9, Rang. — II. gihhosce similis sed magis 

 elevatim et rotunde inflata ; apice breviori, uncinato, append- 

 icibus lateralibus parvis. — The swollen part of the upper 

 division is more raised and rounded than in sp. 6 ; the 

 appendages closer and the apex short and hooked. 



8. L^viGATA, f. 12, Orhigny. — Minuta alba, subrotunde 

 complanata ; rostro hand producto; apice acute uncinato. — A 

 minute white shell with rounded and flattened discs. The 

 mouth is semilunar, without any produced rostrum. Apex 

 small and hooked. 



9. QUADRiDENTATA, f. 17, 18, LssueuT. — Succiuea, ovata, 

 disco ventrali tumido, dorsali triloba to ; apice producto 

 rotundo bis-pinoso ; appendicibus lateralibus approximatis. 



