M. Valenciennes on the Organization of Lucina and Corbis. 41 



Section TRIMERA. 



Family Coccinellid^. 



Scymnus Galapagoensis, Seym, ater, pubescens ; capita piceo ; tho- 

 race utrinque flavo ; elytris pallide testaceis, indistinctissime punc- 

 tulatis ; sutura, margine anteriore, fascia valde flexuosa, maculisque 

 duabus subapicalibus, nigris ; antennis pedibusque flavis. — Long. 

 Corp. f lin. 



From James' Island. 



This species is about equal in size to tbe Sc. minimus ; its form 

 is rather more elongated and less convex than in that insect. The 

 suture of the elytra is black ; the black forms a broad mark at 

 the base, but becomes very narrow towards the tip of the elytra ; 

 the outer margin of each elytron is narrowly edged with black, but 

 on the anterior third the dark colour is suddenly expanded, and 

 forms a broadish mark which extends to the humeral angle, and 

 there meets a broad transverse black mark which crosses the base 

 of the elytra : about the middle of the elytron is a nari'ow black 

 fascia, which as it parts from the suture descends, about the 

 middle is suddenly bent upwards so as to become longitudinal, 

 and then again descends obliquely outwards and nearly reaches 

 the outer margin : behind this central band is an oblique black 

 spot. 



VI. — On the Organization of the l^ucinse and 0/ Corbis. 

 By M. A. Valenciennes*. 



Those anatomists who have been engaged in the study of the 

 Acephalous MoUusca, that numerous class of animals related to 

 the oysters, mussels, &c., regard as one of the constant characters 

 of these creatures, that the respiratory organ fixed on each side 

 of the body under the folds of the mantle is composed of two 

 pairs of branchial leaflets, i. e. that under the common covering 

 of the body there are four branchiae arranged symmetrically on 

 each side of the visceral mass. 



These branchiae are in some pectinated, or composed of small, 

 straight and triangular laminae arranged close together; the 

 oysters, scallops, and the Spondyli present examples of this general 

 sti:ucture, which calls to mind that of the branchiae of almost all 

 the osseous fish. In other Acephalous MoUusca the pectinated 

 lamellae are connected by numerous transversal ridges which im- 

 part more consistence to the branchial leaflet and render it more 

 dense ; the Anodonta, so common in all our fresh waters, ofier, 

 with a large number of other Acephala, examples of this struc- 

 tui-e ; a confirmation which is seldom met with in fish, for Xiphias 

 is the only one in which I have observed this arrangement. 



♦ From the Comptes Rendus, June 9th, 1845. 



