412 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 37. 



This is an extremely distinct species, although bearing evident rela- 

 tionship to the S. leucoptera of Verrill and the NectoteutMs pourtalesii 

 of the same author, both of which are Atlantic forms. The superficial 

 resemblance which the latter species bears to the Hawaiian form is 

 very great, but the broad dorsal commissure uniting the head and 

 mantle at once distinguishes S. iris. 



Genus ABRALIA Gray, 1849. 



ABRALIA ASTROSTICTA, new species. 



'51 



•9 



Mantle firm, fleshy, cylindrical in shape, taper- 

 ing, at first gradvially, then more abruptly, to a 

 bhmtish point; anterior edge smooth, emargi- 

 nate below the funnel. Inner surface of the 

 edge of the mantle articulating with the head 

 in the nuchal region and with 

 the sides of the siphon at the 

 base, as usual in the genus. The 

 dorsal apparatus consists of a 

 simple longitudinal ridge on the 

 mantle and a corresponding plate 

 of. cartilage on the neck. The 

 ventral cartilages comprise a 

 slender linear ridge on either 

 side of the inner surface of the 

 mantle, and grooves with thick- 

 ened edges on the base of the 

 funnel. 



Fins moderately large, subter- 

 minal, triangular, each about as 

 broad as long; attached along 

 most of their inner margin. 



Head rather large, squarish, 

 flattened above and below; four 

 oblique, fleshy folds behind the 

 Eyes large; orbit with a small 

 rounded sinus in front. Funnel large, subtriangular, 

 its center rounded and protruding ventrally, so that 

 it has a ventrally swollen appearance. 



Sessile arms rather short, the second and fourth 

 pairs the longest; first and third pairs about equal 

 in length ; outer edge of arms furnished with a membranous or fleshy 

 keel, which reaches its maximum development on the ventral arms. 

 Armature consisting mainly of hooks in two alternating rows; suckers 

 minute, appearing only at the extreme tips of the arms. 



Fig. 4. — ABRALIA ASTRO- 

 STICTA. Ventral aspect. 

 (xlH.) 



eye on either side. 



Fig. 5.— Abralia as- 

 TRosTicTA. Left 



VENTRAL ARM. 



