A REVIEW OF THE MYSIDACEA 179 



men 46 mm., 2 immature males, 31 mm. (type lot) ; 4867, 1 adult 

 female, 46 mm., 1 immature female, 31 mm. 



Distribution. — All the specimens were caught in the Sea of Japan, 

 off the coast of Korea. 



Genus NEOMYSIS Czerniavsky 



Neomysis Czerniavsky, 1882a, pp. 57, 63; 1882b, p. 23. 



Heteromysis Czerniavsky (nee Smith) 1882a, pp. 57, 62; 1882b, p. 33. 



In 1932, discussing the California species belonging to this genus 

 in its widest interpretation, I suggested on the grounds of convenience 

 that it would perhaps be desirable to separate those species with a 

 spiniform apex to the antennal scale (Neomysis, sensu stricto) from 

 those species in which the antennal scale has a rounded apex (Acan- 

 thomysis Czerniavsky) . The genus Neomysis (sensu lato) is growing 

 to unwieldy proportions, and the division into two groups of generic 

 rank would be convenient. Ii ( 1936a) has now taken this definite step 

 and reinstated the genus Acanthomysis for those species with the 

 rounded antennal scale. Zimmer (1915) had previously canceled this 

 genus as a synonym of Neomysis on the grounds of the close similarity 

 of the two genera especially in the form of the fourth pleopod of the 

 male. While recognizing the close morphological similarity of these 

 genera, I accept Ii's conclusion, which I had myself suggested earlier 

 as desirable on the grounds of convenience. 



In 1932 I called attention to two morphological features of N. 

 mercedis, N. franciscorum, and N. kadiakensis that had hitherto 

 escaped notice, namely, the presence of a median sternal process on 

 the last three thoracic sterna of the female and the presence of a baling 

 lobe on the posterior border of the anterior pair of brood lamellae. 

 Ii (1936a, p. 580) has called attention to an unfortunate misprint 

 in my paper, the use of "posterior' instead of "anterior" in describing 

 the lamellae on which the baling lobe is found. Ii states correctly 

 that this lobe is on the posterior border of the anterior pair of 

 oostegites. Ii has found this lobe in other species of the genus, and 

 it would seem to be a universal feature of this genus and probably 

 also of Acanthomysis. 



With regard to the sternal processes Ii could find them present only 

 on the last two thoracic sterna in N. japonica, N. intermedia, N. 

 czerniawskii, and N. nakazawai, and he failed to find them at all in N . 

 spinosa. I can confirm Ii as regards N. intermedia and N. czerniaw- 

 skii, but I have reexamined N. rayii, N. mercedis, and N. kadiakensis 

 and have confirmed my original observation that there are three 

 processes in these species. With regard to N. nakazawai, I believe 

 this species to be synonymous with N. mirdbilis (Czerniavsky) , and in 

 this species I have found two sternal processes in the female. I am 



