180 C. Spence Bate on the Pencidea. 
specimen that I take to be P. sculptilis, Heller. It resembles 
P. afinis in every detailed appearance, except that it has pos- 
terior to the rostral crest a carina flattened at the summit, with 
traces of a longitudinal groove in the median line, and, more- 
over, it has two fine sutures resembling fractures on each side 
of the carapace. One, the longer, commences just above the 
orbital tooth on the frontal margin, and traverses the surface 
of the carapace longitudinally in a waved line to near the 
posterior margin; the other is at the infero-lateral margin of 
the carapace, near the centre of the branchial region. There 
is also a small suture on the infero-lateral margin of the first 
somite of the pleon; but all these I have observed as a con- 
dition in other species. 
The Penceeus monoceros (ensis) of De Haan is undoubtedly, 
I think, a female specimen of P. affinis. 
P. affinis (barbatus) of De Haan I consider to be P. velu- 
tinus of Dana. 
P. Hardwickii of Miers differs froin P. afinis in having the 
tooth over the gastric region apparently broken, and the apex 
of the rostrum a little more curved upwards. 
Peneus fissurus, n. sp. 
Like P. monoceros, but has only six teeth on the rostrum 
and one on the gastric region. Pleon carinated from the 
posterior portion of the third somite. Fourth, fifth, and sixth 
somites produced to a small dorsal tooth at the posterior margin 
in the median line. ‘Telson armed with a strong tooth on each 
side. 
Taken at a depth of 50 fathoms south of New Guinea. 
There are three remarkable fissures that I have observed in 
other species also traversing the carapace from the orbital to 
near the posterior margin, and from the lateral margin of the 
carapace vertically across the branchial region on each side. 
Penceeus rectacutus, n. sp. 
Rostrum horizontal, straight and sharp, armed on the upper 
surface with eleven ortwelve teeth and one on the gastric region. 
Lower margin straight and fringed with cilia. Dorsal surface 
of the pleon carinated on the fourth, fifth, and sixth somites, 
which last terminates in a posterior tooth. 
Taken in about 100 fathoms of water among the Philippine 
Islands. 
Peneeus brevicornis, Milne-Edwards. (Pl. XI. fig 3.) 
Rostrum very short, scarcely passing the eyes, elevated to 
a crest near the base, styliform, armed with six teeth on the 
