OWBNTA FUSIFORMIS. 363 



second day they had reached the morula- stage. On the third and fourth days the larva 

 is a Mitraria, and soon becomes an active free-swimming form, appearing in the various, 

 tow-nets in St. Andrews Bay, in May and June. 



Habits. — The species is gregarious, occurring in numbers near the surface of the 

 sand, as at Southport, at low-water mark. Fauvel and Watson have kept specimens for 

 years in small aquaria, without change of sea-water, so that they are hardy — muddy sand 

 being, it is said, almost as important as abundance of oxygen. The tubes are buried in 

 the sand in a definite direction, each end having a minute aperture, and the animals can 

 reverse themselves in the tube, and invarably eject the excreta into the surrounding water 

 from the anterior end, which is near the surface. The tube can be moved by the animal, 

 as, for instance, when burrowing in the sand. 



Claparede (1868) stoutly maintained the priority of Delle Chiaje's title, Oweniafili- 

 forniis, notwithstanding that the Neapolitan author only gave figures and a title, for the 

 accuracy of the figure in most respects is, he said, more valuable than a feeble description. 

 Claparede calculated that there were 10,000 hooks in each segment, and no less than 

 150,000 in the whole animal, a considerably lower computation than that of De St. Joseph. 

 The author describes the numerous branches of the blood-vessel, which in the long segments 

 number thirty-five pairs, and have ampulla or dilatations at their commencement. All these 

 debouch into the great dorsal vessel, which surrounds the alimentary canal as far forward 

 as the first torus. Delle Chiaje described a single pair of secretory glands which traversed 

 the segments, and KolKker thought that a pair occurred in each segment. Claparede, 

 however, found four pairs of tube-secreting glands in the Neapolitan examples, the first 

 opening behind the capillary bristles of the first segment. On the other hand, Eisig 

 maintains that fusifor mis and not filiformis is the correct specific name, since the latter 

 was given in error by the Neapolitan author himself. In Claparede's last (posthumous) ' 

 publication (1873) he gives a section of the body- wall, and shows a gland on each side 

 dorsally at the base of the bristle-tufts, whilst the coelom is distended with large ova. 1 



Verrill 2 (1879) includes both Ammocliares assimilis and Owenia filiformis, Delle Chiaje, 

 but there is a misapprehension, for the names are synonymous. 



Von Drasche (1885) gave a careful account of the general and minute structure of 

 this species, with excellent figures. He describes the nervous system as consisting of 

 brain, oesophageal ring, and ganglionated cord (Bauchmark), all of which lie in the 

 hypoderm outside the musculature. He locates the brain under the " Lippen-organ," and 

 states that it consists of " Leydig'schen Punkt oder Fasersubstanz " and ganglion-cells, 

 and he gives a figure and description of a " Schlundcommissur " as occurring on the 

 ventral surface — apparently when the cords are approaching each other — about the first 

 bristle-bundle. His figures of the minute structure of the cords are good, but the arrange- 

 ment of the dorsal and ventral longitudinal muscles, of the alimentary canal, of the 

 mucous glands and blood-vessels, are only briefly alluded to. 



Fewkes 3 (1888) found a Mitraria in the Bay of Funcly, but its actual relationships 

 were then unknown. In all probability it is a larval form pertaining to this family. 



1 ' Annel. Sedent./ pL'viii, fig. 8. 



3 ' Mar. Invert. Atlantic Coast/ Eep. U. S. Comm. Fish and Fisheries, 1879, p. 10. 



3 ' The Microscope/ June, 1888, pp. 1 — 4, pi. vi. 



