ERYONICUS C^ECUS. 115 



podobranchial stems, a condition which also exists in those species of Polij- 

 cheks assigned by Spence Bate to the genus Stereomastis. 



Length from rostrum to end of telson, 62.5 mm.; length of carapace, 

 34.5 mm. ; length of abdomen, 30 mm. ; length of large cheliped, 59 ram. 

 (merus, 12 mm., carpus, 9 mm., basal part of propodite, 9 mm., dactjlus, 

 13.5 mm.). 



Color in life, purplish red, the branchial regions livid. 



Station 3375. 1201 fathoms. 1 male, 62.5 mm. long. 

 " 3377. 764 " 1 fem., 40 mm. " 



" 3383. 1832 " 1 juv., 37 mm. 



" 3388. Surface to 400 fathoms.* 4 juv., 19-29 mm. long. 



Bate's description of Erjjonicus ccecus was drawn up from a single imma- 

 ture specimen, 13 mm. long, captured during the voyage of the " Chal- 

 lenger," off the Canary Islands, ostensibly at a depth of 1620 fathoms. In 

 this specimen the first abdominal appendages were undeveloped. The 

 above-described specimen from the " Albatross " collection is a sexually 

 mature male with well developed gonopods. It differs from Bate's speci- 

 men in having much shorter spines upon the carapace and abdomen, and 

 the spines of the lowest series on the branchial region decrease in length 

 posteriorly, while in Bate's type the longest spines in this row are the pos- 

 terior ones. Whether these differences are due to the difTerence in age or 

 whether they are specific cannot be determined until more mature specimens 

 are obtained from the Atlantic. In the smallest of the " Albatross " speci- 

 mens, which have attained a length of only 19 mm., the spines, especially 

 those of the abdomen, are relatively longer than in the adult, although not 

 so long as in the " Challenger " specimen. In these small individuals the 

 first abdominal appendages are imperfectly developed, and the last thoracic 

 end simply in a short dactylus. 



The specimen from Station 3377 is a female, 40 mm. long. The appen- 

 dages of the first abdominal somite are two-jointed and one-branched, the 

 branch being narrow, flat, ciliated along its margin, and terminating in an 

 obtuse apex (Plate XXX., Fig. 1*). The second abdominal appendage is 

 two-branched, but diifers from the corresponding organ of the male in bear- 

 ing but one stylambly.s. The armature of the carapace differs somewhat from 

 that of the other specimens secured by the "Albatross," and it is ])ossible 

 that this individual belongs to a different species. The median carina is fur- 



* See page 110. 



