The Anatomy of Lazla Cockerelli 
MABEL GUERNSEY 
In a recent number of this Journat the circulatory system of this species was 
described. The present paper is a continuation of that anatomical study. 
In cross-sections of the animal, the body-wall may be seen 
to consist of an outer layer of epithelium; within that a thick 
layer of rather spongy connective tissue, containing spicules, 
blood spaces, and in places gland cells; and within that again a 
thin layer of muscle lining the body eavity. The connective 
tissue and muscle stain with picro-fuchsin in a manner similar 
to mamalian muscle and connective tissue, the muscle fibres 
staining yellowish-brown and the connective tissue pink or red- 
dish. The epithelium is very thin, consisting of a single layer of 
short columnar cells, containing a few mucus cells. Over the 
foot, however, it abruptly changes its character and the cells 
become much elongated and very strongly ciliated, except at the 
anterior margin of the foot, where they lose most of their cilia 
and assume the appearance of gland cells. The connective tissue 
layer is most dense over the back and becomes very loose and 
spongy in the foot, which contains a mass of blood sinuses. It 
contains numerous spicules in the back, a few at the sides, and 
a very few in the foot. These are irregular in shape and size, 
but usually large at the center and tapering toward the ends, 
with a small angle at the center. Sometimes there is a short 
branch springing off near the center or they are more sharply 
angled. Around the spicules, the connective tissue is condensed 
to form a capsule. In the foot the connective tissue contains 
masses of gland cells, grouped just below the epithelium. Over 
the main part of the foot these masses are rather scattered and 
small, but at the anterior angle they abruptly become very 
numerous and closely packed and the separate cells become 
larger. Here also, as has been said, the epithelium changes, 
losing most of its cilia and resembling the gland cells in staining 
reaction. The muscular layer consists partly of a distinct layer 
lining the body cavity and partly of strands of muscles extending 
