BARNACLES FROM GULF OF CALIFORNIA — HENRY 371 



Longitudinal furrow narrow but distinct. Basal ledge narrower 

 than in scutum; widest toward scutal margin. Labrum short, blunt 

 teeth on each side of notch. The margin is hairy. 



Palpi meet over labrum. 



Mandible : Five teeth ; fifth tooth united with inferior angle. Up- 

 per and lower margins hairy. 



Maxilla: Margin straight with seven pairs of spines below the 

 upper pair. Cluster of small spines on inferior angle. 



Cirri. All the cirri have pectinated spines. The spines of the 

 first two cirri are more coarsely pectinated than those of the pos- 

 terior cirri. Cirrus i, subequal rami of 9 and 8 segments. Cirrus ii, 

 subequal rami of 14 and 13 segments; both rami slightly protuberant. 

 Cirrus iii, slenderer and longer than cirrus ii but much shorter than 

 cirrus iv; rami have 21 and 20 segments; fine spines on distal sutures. 

 Cirrus iv and v long and slender; spination like that of cirrus vi. 

 Cirrus vi, median segments with two pairs of long spines and clumps 

 of short spines at the base of each pair. There are multifid spinules 

 on the distal sutures ; the spines at the posterior-distal angle are two- 

 thirds the length of the segment. Both rami have 38 segments; all 

 the segments except those at the tip are twice as wide as long. 



Penis nearly as long as cirrus vi ; dorsal point lacking. 



Remarks. — Chelonibia patula dentata, in addition to the presence 

 of teeth on the lines of suture between some of the compartments, 

 shows several minor differences from typical C. po.fi/7a (Ranzani). 

 The inner lamina is not so distinct from the sheath, the sutures on 

 the interior of the rostrum are usually not very clear, and the inside 

 of the radii are transversely grooved. 



All except the small specimens show teeth on the outer lamina of 

 at least the carina (pi. 31, figs. 11, 12, and 13). In the type specimen 

 there are three teeth on each side of the carina and two teeth on the 

 left carinolateral and left lateral but no teeth on the right or on the 

 rostrum. The teeth differ from those of C. testudinaria (fig. 14) by 

 being coarser and fewer in number (fig. 6), and they are oblique in- 

 stead of parallel to the basis as in that species. 



Chelonibia patula (Ranzani) has never been reported from the 

 west coast of North America, although it is nearly a cosmopolitan 

 species in tropical and subtropical waters. It has been recorded 

 from the Hawaiian Islands by Gruvel, according to Pilsbry (1916). 

 Seven specimens of typical C. patula from Portunus sanguinolemtus 

 from Honolulu from the collection of the Department of Zoology, 

 University of Washington, have been examined and agree with Dar- 

 win's description of this species. 



Chelonibia patula is the least modified species of this genus. The 

 development of the teeth in one to three compartments in C . patula 



