9920 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 
CERATOMYSIS, gen. nov. 
Cephalothorax robust. Carapace short (leaving the last two segments of the 
thorax exposed), spinose ; frontal margin truncate, not forming a rostrum, armed 
at the external angles with a pair of long horn-like spines ; a conspicuous notch 
at the anterior end of the lateral margin serving as an excurrent orifice from 
the respiratory chamber. Abdomen slender, cylindrical, spinose ; sixth seg- 
ment not much longer than the fifth. Eyes absent, their stalks taking the 
form of slender styles, whose tips are soft and delicate, perhaps serving as 
tactile organs. Antennular peduncle rather short ; flagella much longer than 
the peduncle, flattened and fringed with long sete on their margins. Antennal 
scale linear, ciliated on both margins. Mandibular palpi reaching beyond the 
antennular peduncle ; terminal segment long oval, margins fringed with long 
setee. First maxillipeds devoid of an exopod. Distal segment of second max- 
illipeds oval, ciliate. Legs long and slender, propodi not segmented. Seven 
pairs of incubatory lamelle in the female. Fifth and sixth abdominal limbs 
elongated in the female. Telson linear, setose on the margin. Both branches 
of the uropods linear, setose on each margin, subequal, shorter than the telson; 
outer branch not divided by a transverse suture. 
Ceratomysis spinosa, sp. nov. 
In front of the cervical groove are three long erect spines in the median line, 
the foremost of which is on the frontal margin; there is, besides, a spine on 
each side of the carapace in a transverse line with the middle one of the median 
row; behind the cervical groove there is one spine in the median line near the 
posterior margin of the carapace, two on each side of the tongue-shaped dorsal 
area, and a long row of six on each side, in line with the lateral spines of the 
gastric area. Abdomen armed with five longitudinal rows of spines (one me- 
dian, four paired and lateral). Telson very long and narrow, nearly equalling 
the length of the remaining portion of the abdomen. 
Color in life, milk-white. 
Length, 36 mm.; carapace, 9 mm. 
Station 3357. 782 fathoms. 1 female. 
