Brachyura, LATREILLE, 1802

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 200

INFRAORDER BRACHYURA LATREILLE, 1802

A straight, symmetrical abdomen, not used in swimming, characterizes brachyuran crabs. In most brachyurans (and in all of those in California and Oregon), the abdomen is closely bent under the thorax instead of extending posteriorly. The abdomen usually is symmetrical and calcified. The uropods (if present) are not biramous. The cephalothorax is fused with the epistome laterally. The third maxillipeds are broad and often from a cover over the oral field. Pereopod 1 forms a strong cheliped, often with distinctive teeth. The antennae are relatively short in most species. Pereopod 5 is not developed into cleaning brushes or shell-holding appendages as in the Anomura . Consult Garth & Abbott (1980) for good accounts of the natural history of many near-shore and intertidal species.

Recent comparative genetic studies and examination of the genital apparatus in brachyurans have led to different interpretations of the higher classification of brachyurans into sections, tribes or superfamilies. Guinot (1977, 1978) conducted a major reconsideration of the sections, incorporating the location of the genital openings into classification and stressing the importance of the male copulatory structures. She and most other authors have considered the brachyurans to constitute a monophyletic group. Spears et al. (1992), based on a molecular analysis, and Rice (1980) suggested that features of the larval development tended to link some of the "primitive" brachyurans, such as the dromiids, with the Anomura . Ng et al. (2008) summarized new evidence for the Brachyura as a monophyletic group and provided an extensive new description of the group. They also provided morphological and genetic evidence for the arrangement of families into superfamilies and attempted to place them in a sound phylogenetic order. These major works contain further information regarding classification to superfamilies and families.

The key to the families is artificial and based on characters readily visible in species that occur in the area. Family names follow Ng et al. (2008). For the sake of uniformity with other sections of the text, I have omitted the names of sections, tribes or subfamilies.

Benedict (1892b: 224) reported a specimen of Telmessus cheiragonus ( Tilesius, 1815: 347, pl. 7, fig. 1) ( Atelecyclidae ), from "Port Townsend, Oregon ", but Port Townsend actually is in the state of Washington. Kuris et al. (2007: 653) reported Telmessus cheiragonus as being "northern, subtidal, rarely low intertidal" in California and Oregon but did not document the source of this information. Schmitt (1921: 235) reported this species from " California ", but he quoted a report by Holmes (1900: 70) of the crab from "upper California.” Holmes mentioned that there was a specimen of this species at the museum of the University of California. (This specimen has been lost). He noted that the label said that it came from the "Gulf of California ", but "possibly this is wrong as this species appears to be a northern one.” Rathbun (1930: 152) quoted Stimpson (1857b) in saying that the species was collected "off northern California.”

Stimpson (1857b: 465) (as Cheirogonus hippocarcinoides ) said of the species that it "was found on the coast of Upper California by Dr. Le Conte.” John Le Conte was a noted naturalist who studied some of the beetles collected during the United States Exploring Expedition ( Watson 1985). In 1841, that expedition made collections in Puget Sound south to the mouth of the Columbia River, and visited San Francisco Bay. John Le Conte was not a member of the expedition, nor did he collect on the west coast of North America, but he may have sent specimens to Stimpson. Stimpson and others complained that specimens from the Expedition had no labels and their catalog records were lost or in error. The boundary between " Oregon Territory" and "Upper California " was poorly defined in 1841. It is possible that both the collector and the location of Stimpson's specimen from " California " (presumably lost in the Chicago Fire of 1871) were in error.