OF MOLLUSCA. 91 



1. R. melanostoma, t. 51. f. 11. 



2. R. aurata, t. 51. f. 10 ; f. 14, variety of preceding ? 



3. R. lutea, t. 51. f. 12. 



These mollusks appear to take the place of our periwinkles on the 

 Australasian coast. 



■j"f Operculum subcircular, of few rapidly enlarging whorls. 



8. Pagodxjs. 



Shell top-shaped, muricated, imperforate ; whorls suhangular in 

 front ; inner lip rather callous in front, outer striated internally. 

 Operculum ovate, suhcircular ; whorls rapidly enlarging ; edge thin. 



1. P. verus, t. 82. f. 1, 4 ; Adams, Gen. Moll. t. 33. f. 2. 



2. P. , n. s. t. 126 a. f. 4. 



The foot of Pagodus verus is short, simple ; side of the body quite 

 simple. Mouth short, annulated, the lingual band extremely long. 

 — Quay, t. 62. f. 31. Tentacles conical, distant at the base, with 

 eyes or small tubercles on their outer bases. Penis large, club-shaped, 

 placed a little below and behind the right tentacles, conical, covered 

 with minute spicula at the tip, and with two large spinose promi- 

 nences almost one-third down the hinder edge. Operculum subor- 

 bicular, thin, horny, of three or four rapidly enlarging whorls. 



•f"j-f Operculum circular, many-whorled. 



9. ECHINELLA. 



Eyes ? Shell top-shaped, tubercular, perforated ; aperture 



ovate; inner Up arched, edentulous. Operculum annular, of many 

 whorls. — Adams, Gen. Moll. t. 33. f. 3 a. 



1. N. Cumingii. 



10. Modulus. 



Eyes half-way up the tentacles. Shell top-shaped or depressed, 

 perforated ; aperture oval ; inner lip deeply notched. Operculum 

 circular, of many whorls. — Adams, Gen. Moll. t. 33. f. 4. 



1. M. retusus. M. tectum, Adams, Gen. Moll. t. 33. f. 4. 



2. M. trochiformis, t. 126 a. f. 1. 



3. M. lenticularis, Adams, t. 33. f . 4 a (shell only). 



The teeth of Modulus lenticularis are in seven series, 3 • 1 • 3 ; the 

 central broad, denticulated ; outer lateral curved, elongate. — Morch. 



b. Tentacles with a basal internal lobe. Eyes basal. 

 11. Fossar. 



Shell half-ovate, costate, perforated ; mouth half-ovate ; lips thick, 

 outer simple. Operculum ovate. — Adams, Gen. Moll. t. 33. f. 7 a. 



1 . F. ambigua, t. 51 . f. 7, t. 125. f. 7 ; Adams, Gen. Moll. t. 33. f. 7. 



