SPONGES OF BEAUFORT (N. C.) HARBOR AND VICINITY. 145 
SIGMATOMONAXONELLIDA Dendy. 
Family HAPLOSCLERID Topsent. 
Microscleres often absent; when present never chele. The megascleres are usually 
diactinal. Where the skeleton is made up of distinct spiculo-fibers, these are typically 
not plumose. 
Subfamily RENIERINZ. 
Megascleres oxeas or strongyles varying occasionally to styles. Skeleton reticu- 
late, or the spicules may be scattered without definite arrangement. Spongin absent 
or present in small amount; only exceptionally does it envelop the spicules. No micro- 
scleres. 
Reniera Nardo. 
The skeleton is typically a close, uniform, reticulum, each side of the polygonal 
mesh formed by a single spicule. Spongin usually at the nodes of the reticulum. 
The side of the mesh may, however, be multispicular, and long miultispicular fibers 
may develop. 
Reniera tubifera,n.sp. (Pl. LVII, fig. 12; Pl. LVIII, fig. 15; Pl. LIX, fig. 16; Pl. LXVI, fig. 5sa, b,c.) 
Reniera sp., Wilson, 1910. 
A fairly common species in the harbor. The best collecting locality is Newport River, close to 
the town. The sponge is scattered over the bottom and may conveniently be taken at low tide. 
The body of the sponge (Pl. LVIII, fig. 15) is of irregular shape and consists of a reticular system of 
anastomosing cylindrical branches varying in diameter from 3 to 8 millimeters. It is not soft, but 
quite fragile. The specimen figured measures 130 millimeters in length, 30 millimeters in height. 
Rising vertically from the anastomosing branches are numerous tubes, 2 to 10 millimeters high and 1 to 
3 millimeters in diameter, bearing oscula at their tips. In some cases these oscular tubes fuse with 
one another where they come in contact. The walls of the oscular tubes are colorless, thin, and trans- 
parent; the oscula at the tips measure o.5 to 2 millimeters in diameter. 
The dermal membrane of the sponge is delicate and is perforated by numerous irregularly dis- 
tributed pores measuring about 50 u in diameter. The pores open into small subdermal spaces, which 
ramify in the meshes of the ectosomal skeleton and lead into a system of very abundant canals in the 
sponge body (Pl. LIX, fig. 16). The flagellated chambers are conspicuous in stained sections and are very 
numerous. They measure about 25 wu in diameter. The mesenchyme is granular and rather scanty. 
Color of sponge pink or reddish purple, varying to brown; color fading quickly in alcohol. 
Spicules (P1. LXVI, fig. 55a, 6,c).—Smooth, slightly curved oxeas measuring 125 to 170 u by3to 8uyu, 
the smaller sizes, doubtless, being young stages. The usual variants occur in the shape of styles (fig. 54b) 
and strongyles (fig. 54c). 
Skeletal framework (P1. LVILI, fig. 12, Pl. LIX, fig. 16) —The main skeleton (fig. 16) consists of a com- 
bination of fibers, reticulum, and scattered spicules. The fibers course longitudinally through the 
component branches of the sponge and are conspicuous. They are 30 to 100 w in diameter, 3 to 8 spicules 
abreast, the spicules parallel to one another. In the parenchyma between the spiculo-fibers are many 
scattered spicules. These are commonly cemented together with spongin where they meet or cross, 
thus giving rise to a vague and irregular, predominantly unispicular reticulum, There are also many 
free spicules. The dermal and ectosomal skeleton (figs. 12, 16) is a distinct unispicular reticulum. 
The meshes are commonly three sided but may be four or five sided. 
The Beaufort species departs from the typical Renieras, in which the skeleton is a 
unispicular reticuium, and falls in the large group of species in which special multispic- 
ular tracts are developed in the midst of a skeleton that preserves more or less the orig- 
