44 ANOMIAD.E. 



frequently taken delicate, pale, dirty white-brown shells with 

 similar markings, without an appearance of the green insides, 

 and instead of the vermilion animal, they presented a pale 

 yellow aspect; in addition, I have taken from rocks hauled 

 up from the coralline zone, A. ephippium of 3f inches dia- 

 meter, with and without anastomosing striae, and the insides 

 varying from green to light brown and white; and I have 

 little doubt that all the variations I have mentioned are those 

 of the type, A . ephippium, which under no circumstances loses 

 its characteristic sq^^amous character. 



With regard to the young or dwarf A. ephippium, A. squa- 

 mula, A. aculeata, and A. striolata, grouped and crowded on 

 the Pectines, I believe they are mere dwarf varieties of the 

 type ; these often adopt the markings of the substances on 

 which they are fixed, and as often show a complete disregard 

 thereto. I have seen shells combining all the supposed di- 

 stinctive marks in one individual, in which the decided, smooth, 

 glossy A. squamula has commenced the umbonal part of the 

 structure, gradually in respect of the middle portion, gliding 

 into the squamous A. ephippium, and dividing the basal part 

 right and left, the one into the asperities of the A. aculeata, 

 the other into the delicate smooth striulae of the variety^. 

 striolata. Nothing is more common than to see shells half 

 A. squamula and half A. ephippium, and other admixtures of 

 the characters of two or three supposed species. The last- 

 named four varieties are also found at the roots of Algae, but 

 both in colour and the union on the same shell of each other's 

 distinctive marks, they present the same incongruities and 

 discrepancies as their brethren on the Pectines. 



The A. cylindrica or A. cymbiformis, a variety of the 

 A. ephippium, takes its hollowed appearance from embracing 

 the roots of the Fuci; the A. tubularis, another variety of 

 the type, has the margin of the aperture elongated, to suit its 

 condition to some irregularity of the substance on which it is 

 placed. The A. punctata is also a young A. ephippium with 

 papillae-like eminences on the convex valve, and corresponding 

 depressions on the flat one, arising from similar markings on 

 the substances on which thev are fixed. I do not know the 



