496 MAZATLASf UNIVALVES 



624. NASSA TEGULJ, Rve. 

 Conch. Ic. pi. 15, sp. 98. 

 Comp. Buccinum tiarula,* Kien. Icon. Conch, p. Ill, pi. 30, 



f. 4. Rve. Conch. Ic. sp. 92. -= (Nassa) Phrontis t. H. & A. 



Ad. Gen. i. 118. 



This sliell looks like a very small IN", luteostoma, with a white 

 lip. It is of a prevailing slate colour, with a light band round 

 the periphery, and a darker tint above. Sometimes the whole 

 takes an olivaceous tinge. The labrum is more or less strongly 

 lirate internally. The spiral strise are distant, and generally 

 very faint ; but sometimes they are strong enough to make the 

 ribs subnodulous. The last two ribs behind the varix degener- 

 ate into tubercles. The operculum is the exact anologue of 

 that of ]ST. luteostoma, both normally, and in its frequent 

 abnormal changes. The smallest of the adult specimens 

 measures long. '42, long. spir. '17, lot. '27, div. 60. 



An acuminated sp. '6, '24, '38, 50. 



A broad sp. '53, '2, '4, 65. 



Hob. Mazatlan ; not common ; L'pool Col. 



Tablet 2384 contains 7 sp., in different stages of growth. 

 2385, 7 sp. adult, normal. 2386, 2 do. broad. 2387, 2 dp. 

 acuminated. 2388, 5 do. small variety (two with opercula in. 

 situ.) 2389, 6 sp. with opercula in situ, normal and abnormal ; 

 two of the latter are very small in proportion. 2390, 1 normal 

 and 2 abnormal opercula ; sides of the [latter with one or two 

 prongs. 2391, 2 sp. mended after fracture. 2392, 5 sp. shew- 

 ing development of spiral striae, nearly smooth to nodulous. 



624, b. NASSA PTEGULA, var. NODULIFERA, Phil. 



.Nassa nodulifera, Phil, in Mus. Cum. : = (JSTassa) Phontis n. 



ff. $ A. Ad. Gen. i. 118. [Non K nodifera, Pow. in Proc. 



Zool. Soc. 1835, p. 95. Galapagos and Panama, Cuming. 



= (Nassa) Uzita n. H. $ A. Ad. Gen. i, 120.] 



N. t. "N. tegulcs" simillimd ; sed costis ultimis. haud obsole- 

 tis ; striis spiralibus intensioribus ; colore supra fascia pallido, 

 Tubro-fwsco maculato. 



The shells in the last tablet approach this so closely that it 

 is more than probable that the species are identical ; never- 



* The specimens in the B. M. Col. marked B. tiarula, J&en. were received from 

 Mr. Powis as from " South Seas" and "Africa." The habitat assigned by Keeve 

 (without authority) to B. tiarula, is Madagascar. The two species are regarded by 

 Dr. Baird as identical : they are here kept provisionally separate. 



