REVIEW OF SPENGEL’S MONOGRAPH ON BALANOGLOSSUS. 401 
somewhat dorsal to the submedian line—the line in 
which the gill-pores and gonads open in this genus. Of these, 
some just behind the gills are asymmetrically disposed ; whilst 
separated from them by an interval, and placed just in front of 
the liver region are a pair. 
There is no circular muscular layer in the trunk; 
it is replaced by a system of oblique dorso-ventral muscles 
arising from the dorsal mesentery, and ventro-dorsal arising 
from the ventral mesentery. 
The genus Glandiceps is closely allied to Schizocardium. 
It includes two species—one from the deeper zone of the 
Mediterranean, another from the Bay of Tokio, in Japan ; of 
the latter alone the whole body is known, and it will be taken 
as type. 
Glandiceps differs from Schizocardium in the absence of 
synapticula in the gill-skeleton, and of liver saccules ; 
also the pericardium has only two rudimentary ante- 
rior horns. 
The proboscis resembles that of Glandiceps in the 
notochord and muscles. The collar region is extra- 
ordinarily short (PI. 30, fig. 4), and the skeletal rods 
reach right to the end. The peripharyngeal cavities are 
entirely absent. The central nervous system has no roots. 
The inner gill-pores are not so long as in Schizocardium 
(Pl. 29, fig. 14.6). The genital region resembles that of Schizo- 
cardium ; there are, however, additional gonads dorsal 
to gill-sacs, opening in the submedian line. 
In the body musculature and gut-pores Glandiceps resembles 
Schizocardium. The chondroid tissue of the skeleton 
reaches its maximum of development in this genus; 
though there are no liver saccules, a liver region of the gut 
can be recognised by its histological characters, and in this 
region there is a dorsal siphon of non-glandular cells 
opening into the intestine before and behind. 
The genus Balanoglossus includes several species differ- 
ing widely from each other, but agreeing in the follow- 
ing characters :—The central organs of the proboscis are like 
