of the West Coast of North America. 405 



The thick pubescence and the large size and granulated 

 surface of the tubercles on the upper surface of the chelipeds 

 render it extremely difficult to make out details, Avhile at the 

 same time they give it an unmistakable aspect. 



The large tubercles on carpus and manus, knobbed ambu- 

 latory feet, and equal-sized chelipeds at once distinguish 

 this species from P. rudis. 



Porcellana transversillneata^ nov. sp. 



Cara])ax elongate, length to width as one and a lialf to one; 

 a pair of transverse prominences, almost amounting to teeth, 

 just behind the frontal region, followed by several series of 

 short rugaj forming interrupted transverse lines across the 

 carapax ; rugfe becoming longer and more distinct poste- 

 riorly, where they are frequently ca]:»ped with a very short 

 fringe of setffi directed for\vard. 



Gastric region distinctly outlined. Lateral margins of 

 carapax thin, crossed by regularly disposed short ruga?, and 

 ending anteriorly in a sharp spine separated from the post- 

 orbital spine by a deep notcl). 



Front tridentate ; teeth long and acute, central one longest ; 

 lateral teeth slightly deflected. 



Eyes scarcely visible above, hiden beneath the broad bases 

 of the lateral spines ; eye-peduncles long. 



A flat spine below each antenna, at the side of the e])istome, 

 directed forwards and inwards. 



Chelipeds short, subequal ; meros and carpus about equal 

 in length, and equal to the palmar portion of the manus ; meros 

 with a sharp spine at its anterior distal end; carpus with a 

 smaller spine near the centre of its length ; manus broader 

 and thinner than the preceding joints, sharp-edged on botli 

 margins, beset with long setai having a club-like tip ; Angers 

 compressed, parallel, obtusely serrated on their inner edge. 



Ambulatory limbs short, subequal, stout, sparingly beset 

 with setse. 



All the limbs crossed by short squamose ruga?, similar to 

 those of the carapax. 



Abdomen long, the first two joints visible above wlieu it i.s 

 folded below the sternum. 



Boca de las Piedras, Sinaloa, 3 fms. ; also Angeles Bay, 

 west coast. Gulf of California, 5 fms. 



Several specimens, taken in September ; females with ova. 



Length of carapax 6 millims., width of ditto 4. 



Polyonyx nitidus^ nov. sp. 

 Carapax entirely smooth and shining, convex, transversely 



