191S Pomona College Journal of Entomology and Zoology, Vol. X, No. 2, June 



Crabs Taken at Laguna Beach in the 

 Summer of 1916 



H. H. NININGER 



Drawings by John Cofjinan. Determinations by the U. S. Nat Museum. 



While enjoying the pleasant surroundings at Laguna Beacli in the summer of 

 1916, it was my pleasure to make a brief and partial survey of the crabs of that 

 region. In this paper it is intended to give a description of those species taken which 

 may be of use to students who, in the future, may choose to carry on this line of work. 

 The drawings are intended to represent accurately only the outline of form as viewed 

 from the dorsal side. No attempt is made to indicate pubescence (except in a few 

 cases )or irregularities of surface which would require shading. 

 Heterocrypta occidentalis Dana 



This species which was reported by Prof. Hilton from Hermosa Beach in the 

 summer of 1915, was found in abundance directly off Laguna bathing beach in 12-20 

 fathoms of water. Fig. 1 represents an adult male. 



Portunis xantusii (Stimpson) 



These very interesting crabs were taken quite frequently in water of 10-15 

 fathoms. Fig. 2 is of an adult male. 



Cancer gracilis Dana 



Only the young of this species were taken; 5-10 fathoms of water. Fig. 3. 



Cancer gibbosulus (De Horn) 

 Fig. 4 shows the only specimen taken, a young one. 



Cancer productus Randall 

 The only specimen taken was a young one. Fig. 5 outlines the carapace. About 

 15 fathoms. 



Cancer jordani Rathbun 

 Scores of these were taken by dredging. Fig. 6 shows an adult female. The 

 sexes are much alike. They are covered by a rather dense coat of somewhat flexible 

 hairs. The carapaces of the young vary greatly in color. Adults are generally 

 mottled with reddish brown on carapace and legs. Fig. 7 is of a young specimen. 



Opisthopus transversus Rathbun 



Though small, this is certainly one of our most beautiful species. The carapace 

 richly spotted with vermilion to deep red, is polished almost to pearly smoothness. 

 Only a few of these were obtained. Fig. 8 illustrates an adult. 10-20 fathoms. 



Clythrocerus plana Rathbun 



Though they could lay no claim to such beauty as the last named species, these 

 crabs surely received their full share of attention in the aquarium. They persist in 

 carrying about upon their backs pieces of shell, pebbles, sticks, fragments of seaweed, 

 or entire shells with their living contents and seem much embarrassed without some 

 such covering. When placed in a glass dish where nothing else was available, one 

 seized a snail shell more than twice its own size and seemed perfectly content when 

 it had this firmly gripped upon its back. They are found in 15-20 fathoms of water 

 on gravel and shell beds. The two rear pairs of legs are peculiarly modified into 



