CERAPUS. 453 



Say, in his character of the genus, described the 

 flagella to the antennae as consisting of a single joint, 

 a mode of expression not unusual among authors. 

 Milne Edwards consequently established his genera 

 Ericthonius and Cerapodina in consequence of the antennas 

 terminating in multi-articulate flagella. The former was 

 founded upon an animal examined by the author, the 

 latter upon Templeton's inaccurate figure of Cerapus 

 abditus. Professor Dana has likewise founded his genus 

 Pyctilus upon a misconception of the figure of Ericthonius 

 difformis, illustrative of M. Edward's description of that 

 genus, which the artist has drawn with the coxa of the 

 first pair of legs fused with the body of the animal, 

 a circumstance not alluded to in the author's description, 

 and one that Professor Milne Edwards informs us was 

 an error of his draughtsman. It is for these reasons 

 that we are led to consider that these several genera are, 

 together with Dercothoe,* only synonyms of Cerapus. 



The species of this genus are not very numerous, but 

 they have a tolerably wide geographical range. They 

 exist mostly in the warm temperate zones. The form of 

 their abodes appears from Say and Templeton to be 

 membraneous tubes; the former states them to be un- 

 attached to any substance, and carried by the free will of 

 the animal as it swims or walks about a fact which has 

 not been corroborated by any subsequent observer. Mr. 

 Stimpson,inhis "Marine Invertebrata of Grand Manan," 

 p. 47, writing of Cerapus rubricornis, says, " it inhabits 

 flexible tubes, of sizes corresponding to that of the 

 individuals, composed of fine mud and some animal 

 cement by which it is agglutinated. These tubes are 

 generally adherent for about one-half the length and 

 closed below. They are usually found in large groups 

 * Vide page 459. 



