THE SPECIES OF AEGLA — SCHMTTT 



447 



On the outer margin of the movable finger of a number of species 

 near the base there is a definite projecting lobe or angle, usually 

 spined, and, when present, spined in younger specimens if not in 

 the fully developed adults (as in A. platensis) ; sometimes the lobe 

 is reduced in size or suppressed and no more than suggested by some 

 small spinulation at the place occupied by it in other species, or 

 there may be no lobe, angle, or spinulation present at all, the finger 

 being perfectly smooth and rounded off, as in A. laevis talcahuano. 



The carpus of the chelipeds is armed on the inner margin with a 

 row of strong spines, but in this series I do not include the spine that 



rostrum 



rostral carina 



, orbital sinus 



/, orbital spine 



^/ ,, extra-orbital sinus 



anterolateral spine 



epigastric prominence 



ant. margin protogastric lobe 



first 1 



second 



---third 



cervical groove 



hepatic lobe 



--gastric area 

 -internal 



i — anterior 



branchial area 



-posterior 

 cardiac area 

 areola 



Figure 41. — Diagram of Aegla carapace, illustrating some of the terms used in describing 



species. 



may arm what I have called the carpal lobe at the anterior inner 

 angle of the carpus. This angle or lobe may be scarcely more than 

 bluntly rounded off and scabrous, sometimes it is more acute and 

 apically spinulated or furnished with a sharp denticle or small corn- 

 eous spine or two, and it may, as in yl. rioUmayana^ carry a slender, 

 clean-cut, sharp, corneous-tipped spine of good size, about as large 

 and conspicuous as the penultimate spine of the series arming the 

 inner margin of the carpus. The carpal lobe is not always so well 

 developed or so well armed in the female as in the male Aegla; the 

 descriptions given are based on male specimens only. 



More or less parallel to and above the inner spined margin of the 

 carpus there is in most species a definite carpal ridge, usually more 

 or less nodulated, with the nodulations more or less scabrous; on 

 each nodulation there is generally a row of small, corneous scales, 



435661 — 42 2 



