314 14 



Iphiculus spongiosus Adams and White. 

 Iphiculus spongiosus Alcock, LXV, 256, 1896. 



Singapore, 2-3 fath.: XII. 4; 1 c?- Koh Kahdat, 8—10 fath., mud; I. 27 ; 1 ? 

 jiiv. 12 miles east of Koh Mak, 20 fath., large seine; I. 28; Id'. South of Koh 

 Kut, 17 — 20 fath., niud; I. 28; 1 c?. 15 miles west of Koh Kut, 30 fath. (s. m.); I. 

 28; 1 c?. 10—12 miles west of Koh Chang, 20 fath., mud; I. 29; 2 c? 2 ?. 20 miles 

 south of Koh Samit, 20 fath., mud; I. 31; 1 J*. 4—6 miles south of Koh Samit, 

 14—18 fath.; II. 1 ; 1 ? ovig. North of Koh Kut, 15 fath., mud; III. 4; 1 c? 2 ?. 



Arcania septemspinosa (Fabricius). 



Arcania septemspinosa Alcock, LXV, 265, 1896. 



South of Koh Kut, 17—20 fath., mud; I. 28; 4 ? (2 ovig.). 15 miles west of 

 Koh Kut, 30 fath. (s. m.); I. 28; 1 ? juv. 10—12 miles west of Koh Chang, 20 fath., 

 mud; I. 29; 12 juv. 20 miles south of Koh Samit, 20 fath., mud; I. 31 ; 2 c? 2 ? 

 (1 ovig.). Between Koh Chuen and Koh Chang, 15 fath., mud; III. 3; Id". North 

 of Koh Kut, 15 fath., mud; III. 4; 1 c?. 



Arcania siamensis Rathbun. 



Plate I, fig. 11. 

 Arcania siamensis Rathbun, Proc. Biol. Soc. Washington, XXII, 108, 1909. 



Near A. septemspinosa (Fabricius), from which it differs in few particulars: 

 Carapace more subglobular, the branchial regions being more swollen. Surface 

 densely covered with granules visible to the naked eye. The seven marginal spines 

 shorter than in A. septemspinosa; the long lateral spine is less than one-third as 

 wide as the carapace; the five posterior spines are short, subequal, the median one 

 very slightly longer than the others. 



Locality. — Sound at Koh Chang, 3—5 fath., soft clay bottom; 1900; 1 Ç 

 immature (type), 1 small <?• A c? from Singapore, collected by E. Deschamps, is 

 in the U. S. National Museum. 



Length of type Ç, with spine, 17 5 mm.; without spine 157 mm.; width, with 

 spines, 245 mm.; without spines 155 mm. 



Arcania undecimspinosa de Haan. 



Arcania undecimspinosa Alcock, LXV, 266, 1896. 



Koh Kam, 5 fath., gravel; II. 6; 1 c? incomplete. 



Ixa cylindrus (Fabricius). 



Ixa cylindrus Alcock, LXV, 271, 1896. 



4 miles south of Koh Sakait, 9 fath., shell bottom; II. 3; 1 c?. Koh Kahdat, 

 5—8 fath., sandy mud; II. 16 and III. 4; 1 ? ovig. Tung Kaben, 6 fath., sand, 

 mud, phanerogams; II. 22; 1 J". 



