1076 General Notes. [ October, 
Casco bay southward, is familiar with the cast shells of this 
remarkable animal. When found in the course of molting the 
shell, the creature appears as if spewing itself out of itself, as 
the front edge or frontal doublure splits open around the extreme 
edge, the narrow rent, easily overlooked in the cast skin, ending, 
in a half-grown specimen six inches long, including the caudal 
spine, a little over half an inch from the acute hinder edge of the 
cephalothoracic shield. Not only is the outer shell cast, includ- 
ing all the spines and hairs, but also the chitinous lining of | 
«esophagus and proventriculus, the proventriculus corresponding 
to the stomodzum of the embryo. What we call the proventricu- 
lus corresponds to the “stomach” of authors, the true stomach 
not being lined with chitine. How much of the rectum is cast 
is uncertain, but the chitinous parts lying within the body and 
serving as attachments for the muscles moving the caudal spine, 
including two sets of slender, tendon-like processes, are cast 
The gill plates are also cast, as well as the delicate hair-like set# 
fringing their edges. 
Moreover, and this is an interesting pcint, as in this respect the 
molted integument or shell of Limulus is like that of an Asaphus 
we have examined, the seven pairs of apodemes or internal pro- 
cesses, six pairs of which support the six pairs of abdominal feet, 
are also shed. This similarity of form in the apodemes of trilo- 
bites and Limulus has been, to our mind, a strong argument for 
the existence in trilobites of membranous abdominal swimming 
feet like those of the Limulus. ‘ 
A small specimen taken in the act of molting, 50™ long, 1- 
cluding the caudal spine, and 30™™ broad, was considerably 
larger after casting its shell, measuring 65™™ in length, and 4 
in breadth, or about one third larger.—A. S. Packard, Fr. 
CRUSTACEA OF THE NEw ENGLAND COAST, ESPECIALLY OF ie 
‘GULF STREAM SLOPE.— The number of species of this class ate 
added to the faunal lists of this region is quite large, ere 
greater proportion, as was the case with the Anthozoa and omit 
odermata, have been obtained from what is known as the uniting 
grounds ” or “Gulf Stream slope,” that is, from the slope un | 
the continental plateau with the depths of the ocean basin. “tei 
this slope flows the still comparatively warm water of the 
Stream, bearing with it many forms of animal life which "a : 
` previously known to occur north of the coast of Flot ae 2 
between it and the shore flow the cold waters of the polar to live : 
conditions of depth, temperature and nature of bo ; 
none will be found. Thus at some spots 2000 or more of a sp 2 
