504 
W. T. CALMAN. 
of the thoracic somites are easily seen. The investing* cuticle, 
however, is almost uniformly thin, and the tergites, which are 
hardly to be described as sclerites, are defined from one 
another only by superficial grooves. In the posterior part of 
the thoracic region the tergites are regularly transverse, but 
anteriorly the median portions are pushed backwards and 
crowded, together owing to the backward extension of the 
connection between the carapace and the body, which exten- 
sion is visible externally on the dorsal surface of the carapace 
Text-fig. 12. 
Gnatliophausia zoea. Anterior region of body with free 
portion of carapace cut away, from right side. c.f. Origin of 
carapace-fold. ep'. Epipodite of first thoracic appendage 
(maxilliped). ex 2 ., ex*. Exopodites of second and eighth 
thoracic appendages (that of the first is absent in this species). 
gr. Groove marking boundary between maxillary and first 
thoracic somites, uniting above with origin of carapace-fold, 
ma:'. Palp of maxillula. mx" . Maxilla, pip'. Pleopod of first 
pair. I, VIII. Tergites of first and eighth thoracic somites. 
1*. Tergite of first abdominal somite. 
as the “linguiform area” of Sars (1885, p. 22). This crowd- 
ing makes it difficult to count the narrowed anterior tergites, 
but by careful manipulation seven of them can be distinctly 
seen to be continuous across the mid- dorsal line. The fore- 
most of these, the second thoracic tergite, is defined in 
