A REVIEW OF THE MYSIDACEA 249 



are short and stout and only about one-sixth of the length of the 

 distal joint. 



This species is most closely related to A. costata and to A. stelleri. 

 All three are characterized by the folds of the integument on the pleon. 

 A. sculpta is distinguished from the other two by the details of the 

 ornamentation of the pleon, by the form of the telson, and by the 

 structure of the fourth pleopod of the male. 



ACANTHOMYSIS sp. ? 



Neomysis sp. Tattersall, 1941, p. 6. 



Distribution. — Known only from Magdalena Bay, Baja California, 

 in 10 to 15 fathoms. 



Remarks. — In 1941 I recorded the occurrence of two female speci- 

 mens of a species of Acanthomysis from Baja California, which, in 

 the absence of males, I could not satisfactorily determine, though 

 suspecting that they probably represent a new species. The speci- 

 mens come nearest to Acanthomysis macropsis (Tattersall), A. pseu- 

 domacropsis (Tattersall), and A. columbiae (Tattersall). They 

 differ from the first two of these species in having more or less normal 

 eyes without specially elongate eyestalks, and from the last of the 

 above species in the absence of a supraocular spine on the anterior 

 margin of the carapace. The carapace is broadly rounded anteriorly 

 and somewhat vaulted, very similar to the condition seen in A. pseu- 

 domacropsis except that the rostral plate is perhaps more produced 

 in relation to the anterolateral spines of the carapace. The telson 

 resembles most closely that of A. pseudomacropsis in that the lateral 

 margins are closely set with spines and the shape is lingular. 



PRONEOMYSIS WAILESI Tattersall 



Figures 93, 94 

 Proneomysis wailesi Tattersall, 1933, p. 21, figs. 12, 13. 



Distribution. — This species is known only from the waters of British 

 Columbia in 3 to 25 fathoms. 



Remarks. — This species may be recognized by the following char- 

 acters: (1) The carapace is hardly produced into a rostral plate, the 

 anterior margin is broadly and evenly rounded, and the anterolateral 

 corners are acute. (2) The eyes (fig. 93, a) are not elongate, are large 

 and globose, cornea occupying much more than half the eye and wider 

 than the stalk, pigment black. (3) The antennal scale (fig. 94, a) 

 is very short, not longer than the antennular peduncle, five times as 

 long as broad. (4) The labrum has a spinous process. (5) The 

 endopods of the third to the eighth thoracic limbs (fig. 93, b) with 



