4 c Cumacea. 



Station 27c. "Lagoon-bay at CoUinson point, Alaska, 15th September 

 1913. 0-1 foot of water." 1 adult male. 



Remarks. — ^The females and young males from the first-named locality 

 differ from typical specimens of D. sulcata in lacking the furrow from which 

 the species takes its name. While the spiniferous ridge crossing the frontal lobe 

 is well-marked, its vertical continuation on the side of the carapace is indistinct, 

 and there is no horizontal ridge or furrow above the lower margin. The only 

 other differences worthy of mention are that the postero-lateral prolongations 

 of the last thoracic somite are shorter and less acute, and that the telson, instead 

 of being longer than the peduncles of the uropods, is a little shorter. 



On the other hand the specimens agree with D. sulcata and differ from D. 

 rathkii in the less inflated form of the carapace, which is smooth except for the 

 transverse row of spinules on the frontal lobe, and in the greater backward 

 prolongation of the side-plates of the third and fourth free thoracic somites, 

 leading to a marked separation between the second and third pairs of legs. It 

 must be admitted that these differences of f acies are hard to define with precision 

 and are unconvincing as a ground for specific separation. Although the speci- 

 mens appear to me to resemble the types of D. sulcata more closely than they 

 do any of the forms of the polymorphic D. rathkii with which I have compared 

 them, they justify a strong suspicion that D. sulcata may be, at most, only a 

 local race of that species. 



The male from lagoon bay, lacking the supra-marginal furrow of the typical 

 males of D. sulcata described above, approaches D. rathkii even more closely 

 than do the females and it is only recorded here because of its agreement in size 

 with the females found in the same neighbourhood. 



Diastylis goodsiri (Bell). 



Locality. — ^Station 43a. "Off Cockburn point. Dolphin and Union strait? 

 Northwest Territories, about lat. 68° 50' N., long. 115° W., 13th September, 

 1915. About 50 fathoms. Mud with pebbles; no algae." 1 male, 1 female, both 

 immature. "Uniformly white-grey coloured." 



Remarks. — The distribution of this conspicuous and well-known species 

 is given in detail by Hansen (Ingolf Malacostraca, IV, 1920, p. 58). The present 

 record extends its known range somewhat to the west but there remains a large 

 gap towards the eastern record of 116° E. (Stuxberg). Further research may 

 diminish or obliterate this gap, but is appears significant that the species was 

 not found among the rich Alaskan and Bering sea collections of the U.S. Na- 

 tional Museum (Caiman, Proc. U.S. Nat. Mus., XLI, 1912, p. 662). 



Diastylis spinulosa Heller. 



Locality. — ^Station 43a. "Off Cockburn point. Dolphin and Union Strait, 

 Northwest Territories, about lat. 68° 50' N., long. 115° W., 13th September, 

 1915. About 50 fathoms. Mud with pebbles, no algse." 1 female (broken). 



Remarks. — -The specimen is very fragmentary, but, in spite of the 

 presence, on the surviving portions of the carapace, of more numerous spinules 

 than are usually attributed to this species, there can be little doubt as to its 

 identification. The species has not been recorded west of 74° 20' W., or east of 

 83° 8' E. 



