iQi6. J ,S. Kemp : Notes on Crustacea Decapoda. 387 



border there are 2 in one specimen and 3 in the other. The telson 

 in one case bears four pairs of dorsal spinules, in the other five. 



De Man has drawn attention to the great development of the 

 third maxilHpedes and first peraeopods in the male. In the two 

 specimens obtained by Dr. Annandale this character is well shown, 

 the proportions of the limbs agreeing precisel}^ with de Man's des- 

 cription. The enlargement of these appendages in the adult male 

 is a feature of considerable interest, for though apparently rare in 

 the genus Spirontocans, an almost precisely similar phenomenon 

 is met with in the genera Alope and Saron. 



"'Yjf- Tanabe, Kii prov., Japan. S. Voshida. Two, 34, 36 mm. 



The third maxilHpedes in the larger specimen are 30 mm. in 

 length ; in the smaller they are 26 mm. 



Genus Thor, Kingsley. 



The definition of this genus requires modification in order to 

 include T. maldivensis, Borradaile, in which supraorbital spines 

 are found on the carapace. In addition to the greater number of 

 segments in the carpus of the second peraeopods and the presence 

 of a movable plate at the distal end of the antennular peduncle — 

 characters by which the genus is readily distinguished from Hippo- 

 lyte — the outer antennular fiagellum, in Thor, is greatly swollen 

 in both sexes. 



An interesting species, hitherto undescribed, was obtained at 

 Port Blair ; it lives commensally with giant sea-anemones of the 

 genus Discosoina and is very peculiar in its pigmentation. 



The three known species of Thor, all of which have been found 

 in the Andamans, may be distinguished as follows : — 



I. Rostrum with two or more dorsal teeth; 

 supraorbital spines absent. 



A. Apex of rostrum bifid ; lateral process 



of antennule without a tooth at its 



proximal end ... ... T. paschdlis (HeWev). 



B. Apex of rostrum simpl)- pointed ; 



lateral process of antennule with a 

 small upstanding- tooth at its prox- 

 imal end ... ... ... T. cfiscosoDiiifis, sp.nov. 



II. Rostriun with only a single dorsal tooth; 



supraorbital spines present ... ... T. niatdiveiisis, Borra- 



daile. 



Thor paschalis (Heller). 



1914. Tlwr pasclialis, Kemp, Rec. hid. Mas., X, p. 94, pi. i, fio-s. 6-10. 



Additional specimens are from Singapore and from Port Blair 

 in the Andamans, The species was found on several occasions in 

 the latter locality, living among weeds at depths of from 2 to 5 

 fathoms in .^e neighbourhood of Ross I. The specimens are 

 smaller than the majority of those obtained in the Gulf of Manaar ; 

 the largest is only 8 mm. in length and ovigerous females some- 

 times do not exceed 6-5 mm. The single individual from Singa- 

 pore, a male, was obtained at low water under a block of coral. 



