728 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [30] 



Largest specimen. 

 Length, 10""'". 

 Width, 0.5'°'^. 

 Number of segments, 49. 

 This species lives in delicate sand tubes; lo^v water. • 



PRIONOSPIO {Malmgren) Bars. 



PmONOSPio (species not determined). 



A single specimen, too much injured for identification, was dredged 

 in the harbor. Bottom muddy, covered with dead eel-grass. 



STEEBLOSPIO Webster. 



Streblospio Benedicti Webster. 



(Pl. V, Figs. 60-64.) 

 Ajinel. Cliaet. of New Jersey, p. 120, pl. v, figs. 48-50. 1880. 



The head (fig. G) is emarginate in front. The lobes of the dorsal and 

 ventral rami do not disappear as stated in the original description, but 

 become much smaller ; the error arose from not studying transverse 

 sections. 



We found this species in great numbers at Wellfleet, above the har- 

 bor, living in soft, black mud, which formed a layer, two or three 

 inches thick, over compact sand. The tubes were placed vertically in 

 the mud, very close together. They were not as large as the specimens 

 found in New Jersey. 



The anal segment has a shallow sucker (fig. 64), with thick, rounded 

 margin. 



SPIOPHANES Grube. 



Spiophanes Verrilli n. sp. 



(Pl. VI, Figs. 65-72.) 



Head (fig. 66) resting on the buccal segment; posterior half raised, 

 presenting somewhat the appearance of a carina; anterior half rapidly 

 widening, thin, depressed, with anterior angles much prolonged. Eyes 

 four, small, black, lateral; anterior pair about on the middle line; pos- 

 terior pair half way between the anterior j)air and the i)Osterior margin 

 of the head. 



We were unable to find the minute posterior antenna represented a« 

 belonging to this genus. 



Tentacles (fig. 65) reaching back to the eighth segment; canalicu- 

 late, margins of canal rounded and scolloped. 



The dorsal cirri on the anterior segments are wide at base, narrowed 

 at about the middle, with their outer half conical (fig 67); the base grad- 

 ually becomes more swollen, the apex more attenuated, until the middle 



