256 BULLETIN OP THE BUREAU OF FISHERIES. 



KEY TO SPECIES. 



Four strong spines at the top of the zooecium armata 



Zooecium unarmed elongata. 



Hippuraria armata (Verrill). [PI. xxix, 84, 843., 840.] 



Verrill, in Verrill and Smith, 1874, p. 710 (.Vesicularia armata, Verrill, n. sp.), Verrill 18790, p. 28 (Vesicularia armata). 



"Cells stout, oval, broad at base, with a short and narrow pedicel, attached either singly or in pairs 

 along slender, filiform, creeping stems, which often anastomose, the branches being mostly opposite. 

 Distal end of cells prolonged into four conical processes, each of which, when perfect, supports a long, 

 slender spinule, nearly half as long as the cell. Tentacles not seen. Cells yellowish horn-color, with an 

 oval, dark brown internal organ, visible in most of the cells" (Verrill, 1. c.). 



Verrill very evidently overlooked the flattened membranous area which is characteristic of this 

 family, but it must be recalled that the papers of G. O. Sars, on Triticella, and of Busk, on Hippuraria, 

 had not at that time made their appearance. The zooecia arise in pairs on either side of the stem at the 

 end of an internode, each cell arising from a protuberance, from which also the branch takes its origin 

 immediately below the zooecium. The branches are not formed at every internode, though zooecia 

 usually are, and occasionally a branch arises on one side only. They are usually in pairs, however, like 

 the zooecia, and the latter are very rarely suppressed on one side. The prominence is present in all cases, 

 and not infrequently bears the evidence of having lost the zooecium. This, I believe, led to Verrill 's 

 statement that they may be attached singly. While the stolon is characteristically creeping and adnate 

 it is not unusual to find erect shoots, an inch or more in height, beautifully symmetrical and frond-like 

 in appearance. A small but distinct gizzard is present, not completely surrounding the gut, but forming 

 several rounded lobes, with pointed teeth projecting into the cavity. A gizzard has not heretofore been 

 noted in this family, and its presence may indicate a separate genus, but the general character of this 

 species is so similar to Hippuraria that I have included it in this genus. 



"Vineyard Sound on floating seaweed, also in 6 to 10 fathoms, rocky, on Sertularia argentea" (Ver- 

 rill). Vineyard Sound and Buzzards Bay, fairly frequent; dredged in 4 to 15 fathoms, on various 

 bottoms; also from the piles of wharves at New Bedford, Woods Hole, Edgartown, Katama Bay, and 

 Nantucket. Best developed on piles, where the erect branches are of frequent occurrence. 



Hippuraria elongata, new species. [PI. xxix, fig. 85, 853, 8sb, SSG.] 



Zoarium entirely creeping, the stolon slender, transparent to light brownish in color, jointed, the 

 internodes sometimes elongate, but often very short; branches paired, arising from a lateral projection 

 on either side at the end of the internodes, the same projection giving rise to a zooecium ; spreading over 

 the gill-chamber or upon the carapace of various species of crabs. Zooecia rather large , elongate, mounted 

 on slender pedicels, tapering slightly toward both ends, the apex truncate or rounded in contraction, a 

 membranous area on the ventral side extending sometimes nearly the whole length of the cell and again 

 not more than two-thirds of the length; the pedicel varies greatly in length, sometimes shorter than the 

 cell and again more than twice as long, thin walled and transparent, with a flexible portion at the top 

 partly involving the base of the zooecium; the pedicel increases in size toward the top, where it. merges 

 into the cell rather gradually at the flexible portion. The zooecia arise in pairs from lateral processes at 

 the ends of the internodes just as in H. armata, but the internodes are often so short that the zooecia are 

 brought close together and the substratum covered with a close nap of the cells. 



A commensal species, found in the branchial chamber of the blue-crab (Callinectes sapidus) and 

 spider-crabs (Libinia sp.), and occasionally spreading out to a small extent along the bases of the legs, 

 also on the backs of the small crabs (Pinnixia sp.), living in the tubes of Chcetopterus. Taken a number 

 of times in Buzzards Bay and Vineyard Sound. Also abundant at Beaufort, N. C. , in similar situations. 

 The walls of the branchial chamber of the larger crabs are sometimes thickly clothed with the zooecia, 

 and not infrequently the gills are more or less infested with them. Pinnixia is sometimes completely 

 covered on the backs and legs with the white nap-like colonies. 



