110 Bulletiyi Vanderbilt Marine Mitseum, Vol. VI 



Technical description : Carapace compact, median or great- 

 est height equal to four-fifths of length, sides moderately convex, 

 produced in the median dorsal line to a crest-like rostral carina 

 that arises slightly posterior to halfway the length of the carapace 

 and extends forward confluent with the long, curved rostrum, 

 which is one and one-sixth times as long as the carapace. There 

 are three laterally compressed, acute, procurved spines, the series 

 increasing in size from the epigastric, or proximal spine, forward, 

 the third spine being just above the orbital angle ; there is a fourth, 

 subequal spine just in advance of this on the rostrum above the 

 cornea, and a fifth, slightly smaller spine, subequally spaced in 

 advance of the fourth spine. The rostrum is vertically much ex- 

 panded, with the dorsal margin concave, dipping lower than the 

 carapace carina, and the distal half is directed abruptly upward 

 on a much higher plane than the carapace and has the apex trun- 

 cate and tridentate ; the lower proximal portion of the rostrum is 

 much expanded, with the distal lower portion less so, there being 

 nine teeth on this margin, the proximal four of which are deep, 

 approximately equal, well separated by deep sulci ; the first and 

 second of these teeth occur immediately in advance of the eye 

 and are directed nearly straight downward, while the third and 

 fourth teeth are directed obliquely forward, the fifth to ninth teeth, 

 inclusive, have their apices directed nearly straight forward. The 

 acute antennal spine is the only other spine present on the cara- 

 pace. The frontal margin curves regularly to the weakly subacute 

 anterolateral angle. 



The antennular peduncle extends as far as the second rostral 

 tooth, or is three-fifths as long as the scaphocerite ; the first article 

 is rectangular, deeply concave dorsally, with the outer distal angle 

 produced into a very acuminate spine, which extends to the base 

 of the third article and which is separated proximally from the 

 main portion of the first segment by a deep, oblique incision ; the 

 second and third articles are fleshy, short, subcylindrical, the dis- 

 tal one not deeply cleft ; the flagellum is biramose, the upper branch 

 being the thicker, and extending for about one-third its length 

 beyond the rostrum ; the lower branch is twice as long as the upper 

 one and very fine. 



The antennae have the basal article two-fifths as long as the 

 scaphocerite, with the outer lateral margin thick, terminating 

 distally in an acute spine ; the scaphocerite is a little shorter than 



