Isis, 1825, p. 73G. 



TOMOPTERIS INNATANS. 159 



ToMOPTERis Eschscholtz. 



TOMOPTERIS INNATANS, Sp. nov.^ 



Plate 27, fig. 3. 



Body not pigmented, transparent, or nearly so. 



The body has a conspicuous caudal appendage, or tail, on which the para- 

 podia are reduced, or rudimentary. In the type there are eighteen distinct pairs 

 of parapodia, of which the last three pairs are on the caudal appendage and are 

 much reduced, with caudad of them vague traces of a few other parapodia. 



Head with tentacles not thick, relatively long, flattened, and moderately 

 acuminate. First tentacular cirri not present. The second tentacular cirri 

 longer than the body, but not more than half as long again. 



Brain transversely somewhat oblong, with the caudal side a little concave 

 and the anterior convex and mesally transversely truncate. (Plate 27, fig. 3.). 

 Eyes with pigment black, the number of facets not to be made out with certainty 

 in the types. 



The parapodia have the fins rather large, broadly acuminate beyond the 

 distally rounded or somewhat pointed end of the parapodium proper, conspicu- 

 ously differing from euchaeta, in which the fin forms only a narrow fringe along 

 the side and end. Parapodia more in general form like those of septentrionalis, 

 with the fin-membrane attached along both sides of the rami and extending 

 much beyond. Glands present in ventral fins, or in all excepting the first three 

 pairs ; but the preservation is such that examination for their detailed structure 

 could not be satisfactorily made. 



The length, including the tail, is 10+ mm., and exclusive of the tail, about 

 7 nam. Length of the second cirri 11 mm. In the paratype the cirri are rela- 

 tively longer, length 9.25 mm., where the body length is only 6.5 mm. 



Localities. Cahfornia to Marquesas Islands: Sta. 3788 (lat. 4° 35' N., 

 long. 136° 54' W.). Surface. 8 September, 1899. Two specimens. 



Between Easter Island and the Galapagos: Sta. 4711 (lat. 7° 47' 30" S., long. 

 94° 05' W.). Surface. 31 December, 1904. One small specimen with thirteen 

 pairs of parapodia in front of the tail seems to be this species. Total length 

 6 mm., with the second cirri measuring 8.5 mm. 



This species is like T. euchaeta Chun, in having the second cirri longer than the 



' innatare, to swim upon, or float. 



