No. 424.] NOTES AND LITERATURE. 339 
cavity. "There may be as many as fourteen pairs of functional 
branchial vessels, all the efferent branchial arteries on each side 
being connected by a longitudinal commissural vessel which con- 
tinues forward as the common carotid of that side. "The dorsal 
aorta extends forward into the head region. An inferior jugular 
vein is present, and there is a persistent subintestinal vein which 
does not join the portal system. These characters are among those 
which the author regards as primitive. There is a portal heart whose 
walls contain distinctly striated muscle fibers. "The contractility of - 
the portal heart is included among the primitive characters. 
The following features the author considers to have been second- 
arily acquired. The venous system is asymmetrical. The branchial 
vessels distribute “to gill slits instead of gill arches.” The portal 
system receives blood from the anterior body region. The caudal 
vein connects with the posterior cardinals. The portal heart has 
well-developed valves. H.W. R. 

On Hair in the Equide. 11 discusses the hair 
of Equidz with special reference to peculiarities which, he believes, 
are of taxonomic importance. The chief characters which he finds 
to be of specific value are the shape and size, the extent of develop- 
ment of the medulla, the relative thickness of cortex and medulla, 
and the distribution and arrangement of pigment in the cortex. The 
cuticle exhibits only sight modifications in the several members of 
the group. : 
Much greater variability in the character of the hairs was found in 
Equus caballus than in the zebras. The hairs of zebra-horse hybrids 
show surprisingly little variation, even though the dams were of 
various breeds. The hybrid hairs resemble closely those of the 
zebra sire. 
No evidence was found, so far as hair was concerned, in support 
of um telegony hypothesis. H. W. R. 
Notes. — Wesley R. Coe describes the nemerteans collected by the 
United po Fish Commission steamer Fish Hawk, at Porto Rico, 
in the summer of 1899 (Bulletin United States Fish Commission, 1900, 
Vol II, pp. 223-229). Eight species are represented among the 
very few individuals collected. At least three of the species are new. 
The collections of Professor Verrill, at Bermuda, and Ehrhardt, at 
Barbados, exhibit the same marked scarcity of nemerteans. - 
1 Proc. Royal Soc. Edinburgh, vol. xxiii, pp. 375-390- 6 pls. 
